Building standards technical handbook 2022: non-domestic - July 2022

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0.1 Application

0.1.1Introduction The Building (Scotland) Act 2003 gives Scottish Ministers the power to make building regulations to:

•secure the health, safety, welfare and convenience of persons in or about buildings and of others who may be affected by buildings or matters connected with buildings

•further the conservation of fuel and power and

•further the achievement of sustainable development.

This document gives guidance on how to comply with these regulations.

This is one of two Technical Handbooks, one covering domestic buildings and the other non-domestic buildings. These Technical Handbooks have been issued by Scottish Ministers for the purpose of providing practical guidance with respect to the requirements of the provisions of the building regulations under a notice given in accordance with Section 4(2) of the Building (Scotland) Act 2003. Each Handbook has eight sections. Section 0, this section, is identical in both Handbooks. It covers

general

issues and sets out how and when the regulations apply to buildings and works.

From the 2013 edition onwards, the Handbooks are published electronically and are available free on the Scottish Government, Building Standards Division website.

Sections 1 to 7 give guidance on how to achieve the standards set by the regulations, and there are different sets for domestic buildings and non-domestic buildings. The seven sections each cover a number of related standards. They are:

Section 1 Structure

Section 2 Fire

Section 3 Environment

Section 4 Safety

Section 5 Noise

Section 6 Energy

Section 7 Sustainability

Each of the seven sections consists of an introduction and then general guidance on the standards within the section. This is followed by each standard which has specific introductory information and guidance on how to comply with the standard. At the end of the Handbook, after Section 7, there are the following two sections:

Appendix A: Defined terms.

Appendix B: List of standards and other publications.

The Technical Handbooks are supported by a Procedural Handbook, published separately, which clarifies the intent of the Building (Scotland) Procedures Regulations 2004. A separate procedural guidance document for Crown buildings has also been produced.

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This Technical Handbook gives guidance on achieving the standards set in the Building (Scotland) Regulations. The standards themselves can be found in schedule 5 to regulation 9, and are in the form of ‘expanded functional standards’. That is, the standards describe the functions a building should perform, such as ‘providing resistance to the spread of fire’.

The Building (Scotland) Regulations made by the Scottish Ministers are subject to approval by the Scottish Parliament. The content of the regulations, so far as it relates to technical specifications, is also scrutinised by the European Commission (EC). The EC checks with all the other countries that have adopted the Construction Products Regulations (CPR) to ensure that no barriers to trade in construction products are created, either directly or indirectly by the way products are described.

To meet the requirements of the CPR, materials and construction methods must be described by use of suitable European Standards wherever these exist. As there is a rolling programme of change to these National and European Standards, which includes conversion to, and the further provision of, ENs and harmonised ENs, the Handbooks have been designed to be readily updated. An explanation of the relevance and status of specific European and British standards referred to in the Handbooks is in the section concerned. There is also a list of the publications referred to in the Handbooks provided in Appendix B.

The arrangement of Sections 1 - 7 within the Handbooks relates directly to the Basic Works Requirements of the CPR (as published by the EC), which construction works are expected to satisfy when they have been properly designed and built. The arrangement is as follows:

Section 1 Structure (EC - Mechanical resistance and stability)

Section 2 Fire (EC - Safety in case of fire)

Section 3 Environment (EC - Hygiene, health and the environment)

Section 4 Safety (EC - Safety and accessibility in use)

Section 5 Noise (EC - Protection against noise)

Section 6 Energy (EC - Energy, economy and heat retention)

Section 7 Sustainability (EC - Sustainable use of natural resources)

0.1.3 The building standards system

The building regulations are enforced through the building standards system that is established by the Building (Scotland) Act 2003. The Act sets out the enabling powers that allow the Scottish Ministers to make, not only the building regulations, but also procedural regulations, fees regulations and the other supporting legislation needed to operate the system. The system is designed to ensure that new buildings and works achieve the objectives of the Act in terms of health, safety, welfare, convenience, conservation of fuel and power, and sustainable development.

The roles of those operating the building standards system are explained in detail in the guidance on the procedural regulations. Briefly, the duty to comply with the building regulations lies with the owner, or in some cases the client, for the work. Before work begins a building warrant must be obtained.

For some simpler works a warrant is not required (see regulation 5 and schedule 3), but the regulations still apply. The owner or client again has the duty to comply. The role of issuing warrants and accepting completion certificates rests with verifiers, enforcement is

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by local authorities, and the system is overseen and updated by the Building Standards Division (BSD). BSD forms part of the Scottish Government and acts on behalf of, and is responsible to, Scottish Ministers. These bodies are further explained in the guidance to the procedural regulations.

The building standards system is pre-emptive, ensuring so far as possible that the proposed works will comply with the regulations. It recognises that proposals can change during construction, so there are requirements for amendments to the proposals to be agreed and recorded. On completion, the owner or client must certify that the works have been constructed in accordance with the building warrant and the building regulations. The verifier will make reasonable inquiry to ensure the completion certificate is accurate before accepting the certificate. Usually an inspection of the works will be made, and on most projects some inspection of work in progress will also have been carried out. However verifiers cannot inspect all materials and work on every building site. It is the client that should put in place the contractual and practical arrangements needed to assure themselves that the desired quality of work has been achieved.

0.1.4 Status of Technical Handbooks

The regulations are mandatory, but the choice of how to comply lies with the building owner. This Technical Handbook has been issued by Scottish Ministers, through the Building Standards Division, for the purpose of providing practical guidance with respect to the building regulations. If the guidance is followed in full then this should be accepted by the verifier as indicating that the building regulations have been complied with. However it is quite acceptable to use alternative methods of compliance provided they fully satisfy the regulations.

Failure to comply with the Technical Handbook does not render a person liable to civil or criminal procedures, but proof of compliance with the guidance may be relied on in any proceedings as tending to negative liability for an alleged contravention of the building regulations.

Following the advice in the Technical Handbooks is therefore likely to be the normal way of complying with the building regulations. However, a designer may put forward other ways of meeting the regulations, in the form of alternative solutions.

There are a further two guidance documents that have the same standing as the Technical Handbooks. Scottish Ministers have issued these under Section 4(1) of the Building (Scotland) Act 2003. They are:

•Guide for practitioners 7: Fire Safety Management in Traditional Buildings, published by Historic Scotland, and

•The Scottish Building Standards - Technical Handbook – Conservatories, published by the Building Standards Division.

In due course other documents may be issued by Scottish Ministers to provide further guidance. Such guidance might deal with specific building types, or provide alternative methods of showing compliance with those provided in the Technical Handbooks.

0.1.5 Alternative solutions

The use of expanded functional standards, backed up by detailed guidance, provides a flexible system of control. Consideration of alternative solutions is assisted by the expansion of the functional standards previously used in the building standards regulations to clarify the necessary properties of each building. The need for a formal relaxation of standards is reduced as meeting the full details of given solutions is no longer mandatory. The professional judgement of the verifier, assisted by guidance on questions referred to Scottish Ministers, through the Building Standards Division, decides whether a standard is met.

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In considering alternative solutions, however it is necessary to have regard to the details of this guidance. Where performance standards or policy statements are given, every part of the solution is expected to meet them. As a result, alternative solutions that appear suitable may not be acceptable in detail. For example, some of the solutions offered in relation to the English and Welsh building regulations, in the ‘Approved Documents’ (ADs), are not suitable because the levels of thermal insulation recommended are not the same. Similarly different approaches are taken to the control of fire size and the design of compartmentation which means that constructions meeting the AD on fire safety may not be acceptable. This will vary in time as both ADs and the Scottish Technical Handbooks are updated. Solutions based on other documents, such as British or European Standards, will have to be carefully evaluated to see if the Scottish standards are being met in an appropriate manner.

0.1.6 Domestic and non-domestic buildings

Where any building contains both domestic uses and non-domestic uses, the appropriate parts from each Technical Handbook will need to be used to ensure the standards are complied with in full, for example a caretakers flat in an office building. However, communal rooms or other areas in a block of dwellings that are exclusively associated with the dwellings should be considered using the domestic guidance. Examples of this might be a room used as an office for the operation of a sheltered housing complex or a lounge communal to a block of dwellings. It is also a general principle that where a building or part of a building might be seen as falling into more than one category it should be designed to meet the most stringent recommendations.

0.1.7 Latest changes

The following is a summary of the changes which have been introduced since 1 June 2022. Very minor changes to text have not been included here.

•0.2.1 – Updated list of amended legislation.

•0.5.1 – Guidance amended for work types 1, 17 and 25 of schedule 3 to regulation 5. New guidance provided for new work type 25A.

•Schedule 3 to regulation 5 – Amended for types 17 and 25. New work type 25A added for external wall cladding systems that are a minor repair.

•Regulation 8 – Amended to include new requirements for the prohibition on the use of highly combustible metal composite material panels and fire performance criteria for parts of an external wall cladding system.

•0.8.1 – New explanatory text added for the amended Regulation 8.

0.1.8 Updating

It is intended that this Technical Handbook will be available in electronic form and available free of charge on the Building Standards Division website http://www.scotland.gov.uk/ topics/built-environment/building/building-standards/. It is not expected that the standards will change regularly as these are set in the building regulations and can only be changed with Parliamentary approval. Therefore it is anticipated that the guidance will be replaced more regularly than the standards themselves.

0.1.9 Arrangement of Section 0

Section 0 is arranged to follow the actual regulations. This sub-section provides an introduction to the building standards system. Sub-section 0.2 covers regulations 1 and 2 which are the citation, commencement and interpretation. Sub-sections 0.3 to 0.15 cover

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the significant technical regulations with each sub-section setting out and discussing the regulation with the same number (sub-section 0.3 covering regulation 3 etc.). Regulation 16 establishes which regulations cannot ever be relaxed by Scottish Ministers. These are the regulations on citation and commencement, interpretation, exempted buildings, work not requiring a warrant and the methods of measurement. Regulation 17 was introduced in 2007 to help with the implementation of the Energy Performance of Buildings Directive.

0.1.10 Certification

Scottish Ministers can, under Section 7 of the Building (Scotland) Act 2003, approve schemes for the certification of design or construction for compliance with the mandatory functional standards. Such schemes are approved on the basis that the procedures adopted by the scheme will take account of the need to co-ordinate the work of various designers and specialist contractors. Individuals approved to provide certification services under the scheme are assessed to ensure that they have the qualifications, skills and experience required to certify compliance for the work covered by the scope of the scheme. Checking procedures adopted by Approved Certifiers will deliver design or installation reliability in accordance with legislation.

0.2 Citation, commencement and interpretation

Regulations 1 & 2

Regulation 1

These regulations may be cited as the Buildings (Scotland) Regulations 2004 and shall come into force on 1 May 2005.

Regulation 2

Regulation 2 sets out the defined terms within the regulations. It is not reproduced in Section 0; instead the terms have been incorporated in the list of defined terms which form Appendix A.

0.2.1 Explanation of Regulation 1

Regulation 1 contains the citation and commencement of the building regulations. They apply to buildings and works as defined in the Building (Scotland) Act 2003, other than works exempted by regulation 3, schedule 1. The full text is:

The Act defines a building as any structure or erection, whether temporary or permanent. This is very wide, but there are exceptions in the The Act for:

•any public road (including any bridge on which the road is carried)

•any private road (bridges on private roads are not excluded in the Act)

•any sewer or water main vested in Scottish Water

•any aerodrome runway

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•any railway line

•any large raised reservoir within the meaning of the Reservoirs Act 1975

•any wires and cables, their supports above ground and other apparatus used for telephonic or telegraphic communications.

The term building is, subject to context, taken to include a prospective building, a part of a building and, for extensions, alterations and conversions, it can mean the extension alone or the part subject to alteration or conversion. Works in relation to a building is defined in The Act as including works carried out in relation to the enclosure and preparation of the site. Works therefore includes all construction, demolition and conversion work, the provision of services fittings and equipment, and any work carried out in relation to the site.

The Building (Scotland) Regulations 2004 apply to all buildings and works where an application for warrant is made on or after 1 May 2005. In the case of a Crown building, the regulations apply to all buildings and work where an application for warrant is made on or after 1 May 2009. However, full exemption from the building standards system is provided for defence and national security buildings in legislation under The Building (Scotland) Act 2003 (Exemptions for Defence and National Security) Order 2009, SI 2009 No. 822 (S.6).

The Building (Scotland) Act 2003 (Commencement No. 2 and Transitional Provisions) Order 2009 allows work to Crown buildings that has started prior to 1 May 2009 to continue with immunity from building regulations. In addition, work carried out pursuant to a contract entered into prior to 1 May 2009 will continue with immunity on the basis that work commenced before 1 November 2009. In both cases, work must be complete before 1 May 2012.

Buildings and works related to earlier warrant applications or exempt works commencing before 1 May 2005 are subject to previous building standards and procedures regulations, in particular the time by when these works must be completed. Previously exempt works, in particular any no longer exempt, must have been completed by 2 September 2005, otherwise the exemption falls and a warrant for any outstanding work may be required.

On completion of the works, before the period specified in the building warrant expires, a completion certificate must be submitted. If a completion certificate is submitted for work done without a warrant, the regulations that are applicable are those in force at the time of submission of the certificate, which may well be more onerous that those which would have applied when the work started. Fuller details of the arrangements for submitting warrant applications and completion certificates will be given in the guidance on the procedure regulations.

The building regulations also incorporate requirements previously set in separate Building Operations Regulations (regulations 13-15). These cover the provision of protective works, clearing of footpaths and securing of unoccupied buildings.

The following is a list of all amendments made to the Building (Scotland) Regulations 2004, together with the date they came into force and a summary of the major changes.

The Building (Scotland) Amendment Regulations 2006 (1 May 2007)

•New regulation 17 - inserted to implement the terms of Article 9 of EPBD regarding the inspection of air conditioning systems.

•Schedule 1 - changes to building types 1 and 20.

•Schedule 3 - changes to building types 1,2,5,6 and 19.

•Schedule 5 - minor changes to functional standards. New functional Standards 6.9 and 6.10.

The Building (Scotland) Amendment Regulations 2007 (28 March 2007)

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•Replacement Schedule 2 for that contained in 2006 amendments.

•Schedule 5 - minor changes to functional Standards 6.9 and 6.10.

The Building (Scotland) Amendment Regulations 2008 (4 January 2009)

•Minor changes to reflect requirements of energy performance certificates.

The Building (Scotland) Amendment Regulations 2009 (1 May 2009)

•Schedule 1 - change to paved areas or hard-standing exempt from regulations 8-13.

•Schedule 3 - amended to include certain Crown buildings.

The Building (Scotland) Amendment Regulations 2010 (1 October 2010)

•Schedule 3 - rewording of building type 2A.

•Schedule 5 - minor changes to several functional standards. Re-write of functional Standard 5.1 and new functional Standard 5.2.

The Building (Scotland) Amendment Regulations 2011 (1 May 2011)

•Definition of 'statement of sustainability'.

•Schedule 3 - new work type for any work associated with affixing a statement of sustainability to a building.

•Schedule 5 - introduction of Section 7 (Sustainability).

The Building (Scotland) Amendment Regulations 2012 (9 January 2013)

•Regulation 17 - change to require issue of inspection reports following an air conditioning system inspection.

•Schedule 5 - change to limitation to functional Standard 6.9(c) requiring display of EPC in buildings with a floor area of more than 500 square metres which are frequently visited by the public.

Building (Miscellaneous Amendments) (Scotland) Regulations 2013 (1 October 2013)

•Schedule 5 - change to limitations to functional Standard 2.15 and 3.25; new Standard 3.27 Water Efficiency introduced; change to Standard 7.1.

•Schedule 6 - new Standard 3.27 introduced.

Explosives Regulations 2014 (1 October 2014)

•Schedule 1 - change to exempt building type 1.

Building (Scotland) Amendment Regulations 2014 (1 October 2015)

•Schedule 5 - change to limitations to functional Standards 6.1 and 6.9.

Building (Scotland) Amendment Regulations 2015 (9 July 2013 and 1 October 2015)

•Schedule 5 - change to limitations to functional Standard 6.9 (9 July 2015).

•Schedule 5 - change to limitations to functional Standard 6.3 (1 October 2015).

Building (Energy Performance of Buildings) (Scotland) Amendment Regulations 2016 (13 March 2016)

•Regulation 17 - change to 17(1)(a).

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•Schedule 5 - change to Standard 6.1.

Building (Scotland) Amendment Regulations 2016 (1 July 2016)

•Schedule 5 - new Standard 4.14 In-building physical infrastructure for high-speed electronic communications networks introduced.

•Schedule 6 - new Standard 4.14 introduced.

Building (Miscellaneous Amendments) (Scotland) Amendment Regulations 2017 (30 June 2017)

•Schedule 3 – Type 23A exception text amended.

Building (Miscellaneous Amendments) (Scotland) Regulations 2017 (1 July 2017)

•Regulation 9 - change to recognise new Type 23A in Schedule 3.

•Schedule 3 - new type 23A introduced.

Building (Scotland) Amendment Regulations 2019 (1 October 2019)

•Schedule 5 - change to Standard 2.4.

Building (Scotland) Amendment Regulations 2020 (1 March 2021)

•Changes to defined terms cited under regulation 2.

•Schedule 5 – change to Standard 2.15.

Building (Scotland) Amendment Regulations 2022 (1 June 2022 & 1 October 2022)

•Changes to defined terms cited under regulation 2.

•Schedule 3 - changes to type 17, 25 and new type 25A.

•Regulation 8 – limitations on materials used in cladding systems and internal linings to limit fire growth.

•Schedule 5 – changes to Standards 2.7, 6.1 and 6.7.

•Schedule 5 - new Standard 3.28 Overheating Risk introduced.

•Schedule 6 - new Standard 3.28 referenced.

0.2.2 Explanation of Regulation 2

Regulation 2 sets out the defined terms within the regulations. It is not reproduced in Section 0, instead the terms have been incorporated in the list of defined terms which form Appendix A. The Appendix also includes definitions from the Building (Scotland) Act 2003 and those used in these Technical Handbooks.

In the determination of the description of a building, any use which is ancillary to another use or which is of a minor nature should be disregarded and the building taken to be that of the principal description. Minor uses within the curtilage of a dwelling may also be disregarded, for example a single-room office for use by up to two people. Notwithstanding the above, parts of a building may be considered to be of a separate description where the context requires (for example a caretakers flat should be taken separately from any other part of the building in which it is located).

A dwelling may include any surgeries, consulting rooms, offices or other accommodation, of a floor area not exceeding in the aggregate 50 square metres, forming part of the dwelling and used by an occupant of the dwelling in a professional or business capacity. A

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dwelling may provide bed and breakfast facilities provided this does not exceed two double bedrooms and is not in use for more than half of the year.

Where further guidance on building types is needed to define the proposals for particular buildings, it is included in the relevant section.

0.3 Exempted buildings and services, fittings and equipment

Regulation 3

1.Regulations 8 to 12 shall not apply to any building or any services, fittings and equipment the whole of which falls into any one or more of the exempted types described in schedule 1.

2.The provision of:

a.services, fittings and equipment to, or the demolition or removal of, exempted buildings is exempt, and

b.services, fittings and equipment to, or the demolition of, exempted services, fittings and equipment is exempt.

3.For the purposes of this regulation, for the avoidance of doubt, each such exempted type does not include any of the exceptions expressed in relation to that type.

0.3.1 Explanation

Regulation 3 and schedule 1 set out what buildings and work are exempted from the building regulations. The general principles applied to establish exemption are that the regulations do not need to apply where:

•other legislation covers the buildings or work (types 1 - 3)

•the buildings or work are covered by another regulation (type 4)

•the buildings or work are not normally frequented by people (types 5 - 8)

•the buildings or work are so separated that the regulations are largely inappropriate, and are likely in any case to be supervised by specialists including civil engineers (types 9 - 12)

•the buildings or work are sufficiently minor that they have little or no impact on the public interest and it is not in the public interest to seek to enforce the regulations (types 13 - 15 and 17 - 21)

•the buildings or work are temporary (type 16).

Particular care is necessary where exempted work is in the vicinity of, or attached to, an existing building. The level of compliance of the existing building with building regulations should not be adversely affected when exempt works are undertaken.

Where exempt work requires that alteration is made to an existing building to maintain the level of compliance with building regulations, a building warrant may be required.

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For example where it is intended to construct a porch, which falls within type 18, over an accessible entrance and a new accessible entrance is required.

0.3.2 Schedule 1

Table 0.1 Exempted buildings and services, fittings and equipment

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0.4 Changes in the occupation or use of a building that cause the regulations to apply

Regulation 4

For the purposes of section 56(1) of the Act and these regulations, the changes in occupation or use of buildings set out in schedule 2 shall be conversions to the extent specified by regulation 12.

0.4.1 Explanation

The building regulations always apply where construction occurs, unless exempted by regulation 3, and construction includes alterations and extensions as well as entirely new buildings. When there is a conversion it will be necessary to seek a warrant and possibly to undertake works to improve the standards of the building, or part of the building, concerned.

Regulation 4 and schedule 2 set out what changes of occupation or use of a building are defined as conversions and for which the owner must obtain a warrant before making the change. The warrant for a conversion will only be granted if the standards set out in regulation 12 are achieved and this might well require building works.

Those changes of use or occupation listed in schedule 2 are those which are considered critical due to the risks involved. They relate to:

a.domestic buildings, for example:

•a hotel to a dwelling (type 1)

•use of an attic space as a room within a dwelling (type 1)

•use of a garage attached to a dwelling as a room (type 2)

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•sub-division of a house into two flats (type 3)

•use of a house as shared residential accommodation (type 4)

b.residential buildings, for example:

•use of a hotel as office (type 5)

•use of a hotel as a residential care home (type 6)

•use of offices as a backpackers hostel (type 7)

c.whether a building falls within the exemptions of schedule 1, for example:

•use of a railway signal box as a house (type 8)

d.public access to buildings, for example:

•development of a retail trade in a storage building (type 9)

e.division of a building into different occupancies, for example:

•use of a single shop to provide space for two different occupancies (type 10)

Type 6 in schedule 2 refers to the significant alterations in the type and the number of expected occupants. A significant alteration of type could be considered to occur when there was a significant change in the mobility, the familiarity with building, or the awareness of danger, of the occupants. For example, significantly different types would include:

•patients receiving care and/or treatment in a residential care home/hospital

•children in a residential institution or residential school

•guest in a hotel

•people held in lawful detention.

A significant alteration in number could be considered to occur where it amounted to an increase greater than 25%.

Type 9 in schedule 2 refers to allowing access by the general public where previously there was none. Access by the general public refers to permitting members of the general public to enter a building during opening hours and allowing them to access all parts of the building, other than those parts restricted to staff only.

For conversions it is the intention that the standards achieved in the converted building should be broadly similar to those achieved by entirely new buildings. Schedule 6 to regulation 12 guides the verifier as to where discretion is expected to be necessary. It identifies those standards where it is not expected to be reasonably practicable to have existing buildings fully comply. However, for these standards improvement of the existing building is expected where it is reasonably practicable. This means that matters such as thermal insulation now have to be improved even if meeting the full standard is not practically achievable. Guidance on what is normally reasonably practicable is given in schedule 6 and in the individual sections. Guidance is also given on the treatment of historic buildings.

It is also relevant that the requirements of other legislation, for example regulations made under Health and Safety at Work or licensing legislation, will apply to changes of use, so that risk assessments of changed circumstances will provide protection to the occupants of buildings.

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Table 0.2 Conversions to which the regulations apply

0.5 Buildings work, services, fittings and equipment not requiring a warrant

Regulation 5

For the purposes of section 8(8) of the Act, any work which consists solely of a building or conversion, including the provision of services, fittings or equipment, of a kind specified in schedule 3, shall meet the standards required by regulations 8 to 12 but shall not, subject to the exceptions and conditions, require a warrant.

0.5.1 Explanation

Regulation 5 and schedule 3 specifies what work can be done without the need to obtain a building warrant. However, such work must still comply with the regulations.

Building type 1 means much more work to or in houses does not need a warrant. This could include:

•work external to, but immediately adjoining, the house (e.g. patio, decking, wall, fence, steps or ramp)

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•small penetrations of the external walls or roof (e.g. balanced flues, sanitary pipework, mechanical extract ducts or vent pipes)

•small attachments to the external walls (e.g. canopies or micro-renewables)

•erection, demolition or alteration of non-loadbearing partitions

•electrical work

•an en-suite bathroom or shower room (including associated drainage)

•a central heating system.

The exceptions are intended to safeguard against changes that might have significant effect, such as the removal of structural walls. The following list provides some examples of the various exceptions:

•increasing the floor area of the house (e.g. creation of a mezzanine floor or the infill of a stair well)

•demolition or alteration of the roof (e.g. forming a dormer window or construction of a masonry chimney through the roof)

•demolition or alteration of the external walls (e.g. slapping a new window or door, applying an external wall cladding system). The guidance in clause 2.7.1 to standard 2.7 explains the meaning of external wall cladding system including the various component parts that could make up the system.

•demolition or alteration of an element of structure (e.g. removal of a loadbearing wall)

•work adversely affecting a separating wall (e.g. installing recessed electrical sockets)

•work involving a change to wastewater discharge (e.g. disconnection from the mains system).

The exception about increasing the floor area applies because there will be significant implications arising from such work. Other changes, such as the development of a roof space or a garage as habitable space are conversions in terms of regulation 4, a warrant is required and the standards also apply. Where a roof space has limited boarding inserted to allow access to services or to allow attic storage, or where the removal of a non- loadbearing wall creates a marginal increase in floor area these should not be considered as increasing the floor area.

Building type 2 - buildings, other than domestic buildings or residential buildings, where the public are not normally admitted are granted a similar concession in type 2, allowing many offices and factories for example, to make the kind of small alterations necessary to accommodate changes in production or process. Again however the building work done should be to the standard of the building regulations. Exemptions under type 2 recognise security concerns relating to a prison, a building where a person may be legally detained or legally held in custody, the Scottish Parliament and property owned by Her Majesty in right of Her private estates.

Thus, types 1 and 2 permit virtually any work to be carried out to 1 or 2 storey houses and to non-domestic buildings not more than 7.5m high, other than the exceptions listed.

Building types 3 - 23 - the broad types described above are followed by types 3 to 23 covering more specific work that can be carried out to a wider range of buildings without restricting the work allowed by types 1 and 2. Types 3 to 23 begin with small buildings, particularly those within the curtilage of dwellings (types 4 and 5). Note that some of these may now be in the curtilage of flats or maisonettes provided they are a sufficient distance from the dwellings. A sanitary facility should not be considered to be a wet-floor shower room and such work is not intended to be covered by type 11.

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Building type 17 – the exception to type 17 is intended to apply to any thermal insulation material associated with the application of an external wall cladding system. The guidance in clause 2.7.1 explains the meaning of external wall cladding system including the various component parts that could make up the system.

Building type 23A – a building, used for shelter or sleeping in connection with recreation. This building type is different from other building types in schedule 3 in that they must comply with the requirements of standards 1.1, 3.17 – 3.22 and 4.4. Exceptions are added to recognise galleries, proximity to buildings and boundaries.

Building types 24 - 26 - these are different in that they cover work that is closer to a repair than new work. These replacements are therefore required to be to a standard no worse than the existing, rather than to the standard for completely new work.

Doors, windows and rooflights which are a complete replacement are not considered to be a repair and have to meet the full requirements of the standards (see type 20). For historic buildings, where there is a specific need to match existing doors, windows or rooflights, the principle of ‘like for like’ may still be permitted.

Type 25A limits the exemption for replacement external wall cladding systems to minor repairs that can be carried out to a standard no worse than existing.

As a consequence of this new type, the reference to cladding in type 25 has been omitted.

In relation to work to external wall cladding systems, minor repair means isolated repair or replacement of elements of cladding which are physically damaged or have degraded to the point that the element is no longer fit for its intended purpose.

The changes to type 17 and 25 are intended to safeguard against rapid fire spread on or within external wall cladding systems.

Refer also to requirements specific to work undertaken on cladding systems under regulation 8.

0.5.2 Schedule 3

Table 0.3 Description of building and work, including the provision of services, fitting and equipment, not requiring a warrant

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0.6 Limited life buildings

Regulation 6

For the purposes of paragraph 3 of schedule 1 of the Act (which enables special provision to be made for buildings intended to have a limited life) a period of five years is hereby specified.

0.6.1 Explanation

Regulation 6 deals with constructions that are intended to have only a short life span on site and in view of this the mandatory standards and associated guidance give some concessions to such buildings. These concessions only apply to buildings which are not dwellings.

Standard 3.1 in schedule 5 allows a lesser standard for the treatment of the site of a limited life building, other than a dwelling.

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Section 6 Energy, indicates that less demanding U-values can be adopted for the insulation envelope of certain types of limited life buildings, other than dwellings and residential buildings.

Section 7 Sustainability, does not apply to these limited life buildings.

0.7 Measurements

Regulation 7

For the purpose of these regulations, measurements shall be made or calculated in accordance with schedule 4.

0.7.1 Explanation

Schedule 4 to regulation 7 specifies those methods of measurement that are necessary for the regulations themselves. In the Technical Handbooks certain additional measurements are also used, and references to additional methods of measurement specific to particular sections are included in the introductions to those sections.

0.7.2 Schedule 4

Measurements

Area

1.Measurement of area shall be taken to the innermost surfaces of enclosing walls or, on any side where there is no enclosing wall, to the outermost edge of the floor on that side.

2.A room excludes any built-in fixture extending from the floor to the ceiling.

3.In the case of a dwelling, a room excludes any part where the height is less than 1.5m.

Height and depth

4.The height of:

a.a building shall be taken to be the height from the surface of the ground to the underside of the ceiling of the topmost storey or, if the topmost storey has no ceiling, one-half of the height of the roof above its lowest part, and

b.a storey above the ground or the depth of a storey below the ground shall be taken to be the vertical height or depth as the case may be from the ground to the upper surface of the floor of the storey, and the expressions “a storey at a height” and “a storey at a depth” shall be construed accordingly.

5.In the measurement of height or depth from ground which is not level the height or depth shall be taken to be the mean height or depth, except that:

a.for the purpose of types 1, 2, 3, 4, 5, 18 or 19 of schedule 3, and

b.for any other purpose where the difference in level is more than 2.5m, the height or depth shall be taken to be the greatest height or depth.

General

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6.Except where the context otherwise requires, measurements shall be horizontal and vertical.

0.8 Durability, workmanship and fitness of materials

Regulation 8

1.Work to every building designed, constructed and provided with services, fittings and equipment to meet a requirement of regulation 9 to 12 must be carried out in a technically proper and workmanlike manner, and the materials used must be durable, and fit for their intended purpose.

2.All materials, services, fittings and equipment used to comply with a requirement of regulations 9 to 12 must, so far as reasonably practicable, be sufficiently accessible to enable any necessary maintenance or repair work to be carried out.

3.Subject to paragraph (4), work must be carried out so that materials which form part of an external wall cladding system, or specified attachment, of a relevant building are of European Classification A2-s1, d0 or A1, classified in accordance with BS EN 13501-1:2018 entitled “Fire classification of construction products and building elements. Classification using testing data from reaction to fire tests” published by the British Standards Institution.

4.Paragraph (3) does not apply to materials which form part of -

a.cavity trays,

b.cavity vents,

c.any part of a roof (other than a roof pitched at an angle 70 degrees or more to the horizontal) if that part is connected to an external wall,

d.door frames and doors,

e.insulation and water proofing materials used below the ground and up to 300mm above the ground,

f.intumescent and fire stopping materials, fire barriers and cavity barriers where the inclusion of the materials is necessary to meet the requirements in section 2 (fire) of schedule 5,

g.membranes,

h.seals, gaskets, fixings, sealants and backer rods,

i.thermal break materials,

j.window frames and glass.

5.Work must be carried out so that an external wall cladding system or internal lining does not comprise of highly combustible metal composite material.

6.In this regulation —

“highly combustible metal composite material” means any panel or sheet, having a thickness of no more than 10mm, which consists of a number of

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layers, two or more of which are made of metal, alloy, or metal compound and one or more substantial layer of which is made of material having a gross calorific value of more than 35 MJ/kg when tested in accordance with BS EN ISO 1716:2018 entitled “Reaction to fire tests for products – Determination of the gross heat of combustion (calorific value)” published by the British Standards Institution in 2018;

“relevant building” means a building having a storey, or creating a storey (not including roof-top plant areas or any storey consisting exclusively of plant rooms) at a height of 11 metres or more above the ground and which contains-

a.a dwelling,

b.a building used as a place of assembly, or as a place of entertainment or recreation,

c.a hospital,

d.a residential care building or sheltered housing complex,

e.a shared multi-occupancy residential building.

“specified attachment” means-

a.a balcony,

b.solar shading,

c.a solar panel, attached to an external wall.

“substantial layer” means a layer is one which is at least 1mm thick or has a mass per unit area of at least 1 kg per m².

0.8.1 Explanation

Regulation 8 applies to all building work, and requires that materials, fittings and components used in the construction of buildings should be suitable for their purpose, correctly used or applied, and sufficiently durable, taking account of normal maintenance practices, to meet the requirements of these regulations. For example, external timber cladding for low-rise buildings that is readily accessible and replaceable need not be as durable as that which is to be used at a higher level on medium-rise buildings.

It also implements the European Regulation 305/2011/EU Construction Products Regulation (CPR), in force on 1 July 2013 that replaces the current Construction Products Directive (89/106/EEC). This Regulation requires that products covered by a harmonised European product standard or conforming to a European Technical Assessment should normally have CE marking.

The intention of the guidance below is to provide adequate flexibility to accommodate new techniques as well as proven traditional practices. This guidance ensures acceptance of products which satisfy the basic works requirements of the CPR to avoid barriers to trade. For example, products bearing a CE mark (European Mark of Conformity) must be accepted as meeting regulation requirements where the declaration of performance satisfies the requirement and the product is being correctly used.

Sections 1 - 7 of the Technical Handbooks are arranged to equate with the 7 basic works requirements of the CPR. This should aid assessment of products against the regulation requirements. There may however be other Directives applicable to certain products or constructions.

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A verifier may only reject CE marked products if the declaration of performance does not meet the regulation requirement or the products are being incorrectly used. If the verifier rejects a product the relevant trading standards officer should be notified. This is a requirement of the CPR, and will enable the UK government, where necessary, to notify the European Commission.

It should be noted that CE marking alone does not show compliance with the building regulations, as the CE mark may be showing compliance with other Directives or Regulations applicable to certain products or constructions. For example, a self contained smoke alarm, manufactured in accordance with the Electro Magnetic Compatibility Directive should be accepted as satisfying requirements only insofar as they relate to prevention of electromagnetic disturbances by, and prevention against disturbances to, such smoke alarms.

External wall cladding systems and specified attachments – There may be a risk of fire spread on the external wall of a building due to the presence of combustible external wall cladding systems or specified attachments. Fire could break out through a window or door opening and spread onto the external walls. External walls close to the boundary are also at risk as they may be exposed to direct flame impingement or radiant heat flux from a fire in an adjoining building or other external source e.g. bin fire.

Fire-fighters may not be able to apply a water jet from a fire-fighting hose directly onto a fire that has spread onto an external wall cladding system or specified attachment high above the ground. This is because the external wall is either inaccessible or is out with the reach capability of fire-fighting equipment. Therefore, the construction and materials used on facades of taller buildings should not contribute to the fire development. The 11m storey height in Regulation 8 and in the guidance to standard 2.4 (cavities) and standard 2.7 (spread on external walls) is based on the reach capability of a fire and rescue service ground mounted water jet where there is sufficient pressure and flow in the water main. More detailed guidance on the meaning of external wall cladding system and specified attachments is provided in the guidance to standard 2.7 in section 2: Fire of the Technical Handbooks.

0.8.2 Explanation of terms

There are useful terms and acronyms used in this section included below.

BSI - The British Standards Institution is the UK national standards body. BSI publishes European standards in the UK as BS EN See http://www.bsi.org.uk.

CEN - Comité Européen de Normalisation is the European standards body that prepares harmonised product standards. Declarations of Performance against such standards are expected to provide sufficient information for any member state to allow the product onto their market and for specifiers and users to be able to assess whether the product is suitable for its intended use.

CEN also prepares non-harmonised European standards, such as test or calculation standards and standards for products or services that have not been mandated under a CE Marking Directive.

CEN does not issue standards directly, only through national standards bodies; BSI is the designated standards body for the UK. Further information is available at http:// www.cen.eu/cen.

EA - The European co-operation on Accreditation is the umbrella organisation for all National Accreditation Bodies in Europe. Product certification bodies, inspection bodies and test laboratories approved by national accreditation bodies belonging to EA are equivalent to those approved by UKAS. See http://www.european-accreditation.org/.

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ETA - European Technical Assessments is a favourable technical assessment issued under the European Construction Products Regulation 2011 that allows a manufacturer to affix CE markings on their products. See http://www.eota.eu/.

ISO - International Organization for Standardization is the worldwide federation of national standards institutions. Standards are identified by ‘ISO’ and a number. ISO standards may be published separately or transposed into the UK as BS ISO or BS EN ISO. See http://www.iso.org/.

Materials - include manufactured products such as components, fittings, items of equipment and systems. Naturally occurring materials such as stone, timber and thatch, and backfilling for excavations in connection with building work are also included.

NANDO - New Approach Notified and Designated Organisations is an information system produced by the European Commission. It lists the harmonised European standards and bodies notified by member states to carry out conformity assessment tasks for CE marking. See http://ec.europa.eu/enterprise/newapproach/nando.

UKAS - United Kingdom Accreditation Service is the sole national accreditation body recognised by the UK Government to assess against internationally agreed standards, organisations that provide certification, testing, inspection and calibration services. Accreditation by UKAS demonstrates the competence, impartiality and performance capability of these organisations. See http://www.ukas.com/.

Verifier - the role of the verifier is to protect the public interest by providing an independent check of applications for building warrant to construct or demolish buildings, to provide services, fittings or equipment in buildings, or to convert buildings. Verifiers are appointed by Scottish Ministers.

0.8.3 Performance

Regulation 8 will be met if the following are satisfied:

a.materials used in the construction of buildings are of a suitable nature, quality and in relation to the purposes and conditions of their use, and

b.workmanship is such that, where relevant, materials are adequately mixed or prepared and applied, used or fixed so as to perform suitably the functions for which they are intended.

Materials include:

a.manufactured products such as components, fittings, items of equipment and systems

b.naturally occurring materials such as stone, timber and thatch, and

c.backfilling for excavations in connection with building work.

0.8.4 Materials

Building work must meet the functional requirements of Schedule 5 of the Building (Scotland) Regulations 2004, as amended. The Technical Handbooks refer to materials covered by European harmonised product standards, British Standards, and other technical specifications. However, as there is no obligation to adopt any particular solution contained in the Technical Handbooks in order to meet functional requirements, the references are not exclusive and other materials may be suitable in the particular circumstances.

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The fitness and suitability of a material for use for a specific purpose can be assessed in the following number of ways.

•CE marking under the CPR

Many materials are construction products that have CE marking under the CPR (305/2011/EU-CPR).

The CPR requires that construction products on the EU market covered by a harmonised European product standard should normally have CE marking. In addition, manufacturers of products not covered by a harmonised standard can choose to affix CE marking to their products by obtaining a European Technical Assessment. You can find a list of the harmonised product standards under the CPR on the NANDO information system see www.ec.europa.eu/enterprise/newapproach/nando/index.cfm? fuseaction=cpd.hs.

CE marking includes the reference of the product standard and levels or classes of performance being declared against some or all of the characteristics covered by the standard. The CE marking should be on the product, its label, the packaging or accompanying documents. The CE symbol by itself does not necessarily indicate that the material is suitable for building work.

In addition to CE marking, the product will have a declaration of performance containing more detailed information on the product. This may be a paper or electronic document, or it may be on a website. It is essential to check that the declared performance is suitable for building work.

In the absence of indications to the contrary, the verifier should assume that the information given in the CE marking and declaration of performance is accurate and reliable, and that the product meets the declared performances.

If the declared performance of a product is suitable for its intended use, the verifier should not prohibit or impede the use of the product.

•CE marking under other EU Directives and Regulations

Products may have CE marking under other European legislation, such as the Gas Appliances Directive (2009/142/EC) or the Pressure Equipment Directive (97/23/EC). Such CE marking shows that the product meets the essential requirements set out in the legislation, for example, minimum safety requirements, and can be placed on the EU market.

Some products will have CE marking in accordance with both the CPR and other legislation. The CE marking shows that the product complies with the requirements in all relevant EU legislation.

•British Standards

Nearly all British Standards for construction products are the British version of harmonised European Standards used for CE marking. The British Standards Institution (BSI) numbering policy is to adopt the European Committee for Standardisation (CEN) numbering, prefaced with BS e.g. BS EN 197-1: 2000.

Some British Standards are the British version of non-harmonised European standards; these also adopt the CEN numbering, prefaced with BS. These do not contain an Annex ZA, so CE marking cannot be affixed to products made to these standards.

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Some British Standards for products not covered by a European standard will continue to exist.

Where a construction product has been made and assessed in accordance with one or more British Standards, this may show whether the product is suitable for its intended use.

•Other national and international technical specifications

An international technical specification, including those prepared by the International Organization for Standardization (ISO) http://www.iso.org/iso/home.html, or on a national technical specification of a country other than the UK, may be used to demonstrate that a product not covered by a harmonised European standard meets the performance requirements of the Building Regulations.

Where necessary, the ‘relevant person’ who intends to carry out the work should obtain translations of specifications to demonstrate how the material meets the requirements of regulation 8.

It should be noted that the national technical specifications of other EU Member States (and non-EU countries that are full members of CEN) are being progressively replaced by harmonised European standards, as is the case with British Standards.

•Independent certification schemes

There are many independent product certification schemes in the UK and elsewhere which may be a further source of information on product performance. Such schemes certify that a material complies with the requirements of a recognised document and indicates it is suitable for its intended use. These may be in addition to, but not conflict with, CE marking. It should be noted that, materials which are not certified by an independent scheme may still conform to a relevant standard.

Accreditation of a certification body by a national accreditation body belonging to the European co-operation on Accreditation (EA) provides a means of demonstrating that their certification scheme can be relied upon. In the UK, most independent certification bodies are accredited by UK Accreditation Service (UKAS), which belongs to the EA.

It is important to check the scope of the accreditation of certification body, as accreditation may cover only part of the certification body’s testing or certification business.

•Tests and calculations

Where there is no relevant harmonised European standard, tests, calculation or other means may be used to demonstrate that materials will be capable of performing the function for which they are intended. UKAS or an equivalent national accreditation body belonging to the EA may accredit the testing laboratories. This accreditation provides a means of showing that such tests can be relied on.

•Past experience

Past experience, such as in buildings in use may show that materials can perform the function for which they are intended.

0.8.6 Short lived materials

Some materials, in the absence of special care, may be considered unsuitable because of their rapid deterioration in relation to the expected life of the building.

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Short-lived materials that are readily accessible for inspection, maintenance and replacement may meet the requirements of the regulations if the consequences of failure are not likely to be serious to the health or safety of persons in and around buildings.

If short-lived materials are not readily accessible for inspection, maintenance and replacement, and the consequences of failure are likely to be serious for health or safety, it is unlikely that the material will meet the requirements of the regulations.

0.8.7 Materials susceptible to change in their properties

The properties of some materials can change in certain environmental conditions. These changes can affect the performance of the materials over time.

Materials that are susceptible to changes in their properties may be used in building work and will meet the requirements of the regulations if the residual properties, including the structural properties:

1.can be estimated at the time of their incorporation in the work, and

2.are shown to be suitable for buildings to perform the function for which they are intended, for the expected life of the building.

0.8.8 Ways of establishing the suitability of workmanship

The term workmanship has been included so that references to methods of establishing workmanship can be included in the Technical Handbooks. For example, where performance depends on the construction being carried out with a crucial standard of workmanship, say in the construction of separating walls in a dwelling, it will prove useful to consider the information provided in British Standard BS 8000.

It is not the intention that verifiers check workmanship generally, certainly not for purely aesthetic matters.

It may be useful to consider the following as ways of establishing the suitability of workmanship:

•CE marking

For materials having a CE marking, workmanship may be specified in the relevant ETA or harmonised product standard.

•Standards

Methods of carrying out different types of work are also given in British Standards or other appropriate technical specifications. It should be noted that the BS 8000 series of standards on workmanship on building sites combines guidance from other BSI codes and standards. These are:

•BS EN ISO 9000: 2005 – Quality management systems. Fundamentals and vocabulary.

•BS EN ISO 9000: 2008 – Quality management systems. Requirements.

•BS 8000-1: 1989 - Workmanship on building sites. Code of practice for excavation and filling.

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•BS 8000-2-1: 1990 (AMD 9324 1997) - Workmanship on building sites. Code of practice for concrete work. Mixing and transporting concrete.

•BS 8000-2-2: 1990 - Workmanship on building sites. Code of practice for concrete work. Sitework with in situ and precast concrete.

•BS 8000-3: 2001 - Workmanship on building sites. Code of practice for masonry.

•BS 8000-4: 1989 - Workmanship on building sites. Code of practice for waterproofing.

•BS 8000-5: 1990 - Workmanship on building sites. Code of practice for carpentry, joinery and general fixings.

•BS 8000-6: 1990 - Workmanship on building sites. Code of practice for slating and tiling of roofs and claddings.

•BS 8000-7: 1990 - Workmanship on building sites. Code of practice for glazing.

•BS 8000-8: 1994 - Workmanship on building sites. Code of practice for plasterboard partitions and dry linings.

•BS 8000-9: 2003 - Workmanship on building sites. Cementitious levelling screeds and wearing screeds. Code of practice.

•BS 8000-11: 2011 - Workmanship on building sites – Internal and external wall and floor tiling. Ceramic and agglomerated stone tiles, natural stone and terrazzo tiles and slabs, and mosaics. Code of practice.

•BS 8000-12: 1989 - Workmanship on building sites. Code of practice for decorative wall coverings and painting.

•BS 8000-13: 1989 - Workmanship on building sites. Code of practice for above ground drainage and sanitary appliances.

•BS 8000-14: 1989 - Workmanship on building sites. Code of practice for below ground drainage.

•BS 8000-15: 1990 - Workmanship on building sites. Code of practice for hot and cold water services (domestic scale).

•BS 8000-16: 1997 (A1: 2010) - Workmanship on building sites. Code of practice for sealing joints in buildings using sealants.

•Independent certification schemes

Some independent certification schemes specify how workmanship will deliver a declared level of performance. The relevant person carrying out the work should show that the workmanship will provide the appropriate level of protection and performance.

Schemes, including “Certification of design” and “Certification of constructions” that register installers of materials can provide a means of ensuring that work has been carried out by knowledgeable contractors to appropriate standards. See 0.8.9 Certification.

•Management systems

The quality of workmanship is covered by a quality management scheme, such as one that complies with the relevant recommendations of BS EN ISO 9000, and related series of standards. There are a number of such UKAS accredited schemes.

•Past experience

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Past experience, such as in a building in use, may show that the method of workmanship is capable of performing the function for which it is intended.

•Tests

Tests can be used to show that workmanship is appropriate for compliance with building regulations.

Those carrying out building work may voluntarily include testing to demonstrate that the work complies with the requirements of the building regulations.

Verifiers may request a ‘materials test’ under Section 41 (2) of the Building (Scotland) Act 2003 if they consider it necessary, to establish whether building work and materials comply with the requirements of regulations 8 and 9 of the Building (Scotland) Regulations 2004, as amended.

0.8.9 Certification

Scottish Ministers can, under Section 7 of the Building (Scotland) Act 2003, approve schemes for the certification of design or construction for compliance with the mandatory functional standards. See 0.1.10 for works that can be Certified.

0.9 Building standards applicable to construction

Regulation 9

(1)Subject to paragraph (2), construction shall be carried out so that the work complies with the applicable requirements of schedule 5.

(2)Only the requirements of the standards set out in paragraphs 1.1, 3.17, 3.18,

3.19, 3.20, 3.21, 3.22 and 4.4 of schedule 5 apply in the case of the construction of a building of a type described in paragraph 23A of schedule 3.

0.9.1 Explanation

Regulation 9 and schedule 5 are the heart of the building standards system as they set out what must be achieved in building work. The standards are given in full along with the associated guidance on compliance in Sections 1 – 7 of the Technical Handbooks. Sections 1 - 7 relate directly to the basic works requirements, as published by the EC, which buildings and works. are expected to satisfy when they have been properly designed and built.

The seven sections are:

Section 1 Structure (EC - Mechanical resistance and stability)

Section 2 Fire (EC - Safety in case of fire)

Section 3 Environment (EC - Hygiene, health and the environment)

Section 4 Safety (EC - Safety and accessibility in use)

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Section 5 Noise (EC - Protection against noise)

Section 6 Energy (EC - Energy, economy and heat retention)

Section 7 Sustainability (EC - Sustainable use of natural resources)

The basic work requirements are also subject to overall requirements related to durability, which are covered in regulation 8.

The guidance on suitable provision to meet the building regulation standards is given without assurance that any other legislative or administrative requirement might apply more onerous standards.

In considering which standards apply, where more than one is relevant to any building work all the standards should be met.

0.9.2 Schedule 5

The mandatory standards in schedule 5 are given in the seven sections of this Handbook (Structure, Fire safety, Environment, Safety, Noise, Energy and Sustainability) and are therefore not repeated here.

0.10 Building standards applicable to demolition

Regulation 10

1.Every building to be demolished must be demolished in such a way that all service connections to the building are properly closed off and any neighbouring building is left stable and watertight.

2.When demolition work has been completed and where, no further work is to commence immediately, the person who carried out that work shall ensure that the site is:

a.immediately graded and cleared, or

b.provided with such fences, protective barriers or hoardings as will prevent access thereto.

0.10.1 Explanation

Regulation 10 sets out the mandatory requirements when undertaking demolition work.

The building regulations do not control the method or process of demolition. This is the responsibility of the Health and Safety Executive and is covered under other legislation.

What the building regulations do seek to control is the area which is left after demolition has been completed, and the state of any surrounding buildings affected by the demolition. Any adjacent buildings must be left safe and watertight and all service connections must be properly sealed. Unless it is intended to build on the cleared site without delay, it must be left in a safe condition. This might be achieved by site clearance and grading, or by ensuring adequate perimeter enclosures.

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Regulation 11

Every service, fitting or piece of equipment provided so as to serve a purpose of these regulations shall be so provided in such a way as to further those purposes.

0.11.1 Explanation

Regulation 11 requires that every service, fitting or piece of equipment provided so as to serve a purpose of the regulations should be designed, installed, and commissioned in such a way as to fulfill those purposes.

0.12 Building standards applicable to conversions

Regulation 12

Conversion shall be carried out so that the building as converted complies with the applicable requirements of schedule 6.

0.12.1 Explanation

Certain changes of use or occupation were defined as conversions in schedule 2 and are therefore subject to the building regulations. Regulation 12 requires that in these cases the building shall meet the requirements of schedule 6. However it is recognised that this is not reasonably practicable in many existing buildings. Therefore the schedule also lists those standards where a lower level of provision may well be sufficient. It is essential to establish with the verifier where meeting the standards in full is not reasonably practicable, and early discussion will be necessary. The individual sections of the Handbooks give further details.

For historic buildings, the classification of the building should influence the extent to which improvement is required, depending on whether the classification is for the outside, the inside, all parts, etc.

0.12.2 Schedule 6

Every conversion, to which these regulations apply, shall meet the requirements of the following standards in schedule 5:

a.Standards 2.1, 2.3, 2.5, 2.9, 2.10, 2.11, 2.13, 2.14, 2.15 in Section 2, Fire

b.Standards 3.5, 3.6, 3.7, 3.8, 3.9, 3.11, 3.12, 3.13, 3.14, 3.17, 3.18, 3.20, 3.21, 3.22, 3.23, 3.24, 3.25, 3.26, 3.27 in Section 3, Environment

c.Standards 4.5, 4.6, 4.7, 4.9, 4.11, 4.12, 4.13 in Section 4, Safety

d.Standards 5.1 and 5.2 in Section 5, Noise, and

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e.Standards 6.7, 6.8, 6.10 in Section 6, Energy.

Every conversion, to which these regulations apply, shall meet the requirements of the following standards in schedule 5 in so far as is reasonably practicable, and in no case be worse than before the conversion:

a.the standards in Section 1, Structure

b.Standards 2.2, 2.4, 2.6, 2.7, 2.8, 2.12 in Section 2, Fire

c.Standards 3.1, 3.2, 3.3, 3.4, 3.10, 3.15, 3.16, 3.19 in Section 3, Environment

d.Standards 4.1, 4.2, 4.3, 4.4, 4.8, 4.10 in Section 4, Safety, and

e.Standards 6.2, 6.3, 6.4, 6.5, 6.6 in Section 6, Energy.

Note: Standard 7.1, Sustainability does not apply to conversions.

0.13 Provision of protective works

Regulation 13

1.No person shall carry out work unless the following provisions of this regulation are complied with.

2.Subject to paragraph (3), where work is to be carried out on any building site or building which is within 3.6m of any part of a road or other place to which members of the public have access (whether or not on payment of a fee or charge) there shall, prior to commencement of the work, be erected protective works so as to separate the building site or building or that part of the building site or building on which work is to be carried out from that road or other place.

3.Nothing in paragraph (2) shall require the provision of protective works in any case where the local authority is satisfied that no danger to the public is caused, or is likely to be caused, by the work.

4.The protective works referred to in the preceding paragraphs are all or any of:

a.providing hoardings, barriers or fences

b.subject to paragraph (5), where necessary to prevent danger, providing footpaths outside such hoardings, barriers or fences with safe and convenient platforms, handrails, steps or ramps, and substantial overhead coverings

c.any other protective works which in the opinion of the local authority are necessary to ensure the safety of the public, all of such description, material and dimensions and in such position as the local authority may direct.

5.Nothing in paragraph (4)(b) shall require the provision of a platform, handrail, step or ramp:

a.where no part of the existing footpath is occupied by the protective works or in connection with the work, or

b.where that part of an existing footpath remaining unoccupied affords a safe means of passage for people, and is of a width of not less than 1.2m or such greater width as the local authority may direct.

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6.Any protective works shall be so erected as to cause no danger to the public and shall be maintained to the satisfaction of the local authority.

7.Subject to paragraph (8), any protective works shall be removed:

a.in the case of a building which has been constructed by virtue of a warrant, not more than 14 days or such longer period as the local authority may direct from the date of acceptance of the certificate of completion, and

b.in any other case, on completion of the work.

8.Nothing in paragraphs (1) to (7) of this regulation shall prohibit the removal of the protective works or any part thereof prior to the completion of the work where the local authority is satisfied that no danger to the public is caused or is likely to be caused as a result of their removal.

9.Any protective works shall be illuminated, and any such works which project on to or over that part of a road which is not a pavement or footpath shall be provided with such markings, as in the opinion of the local authority are necessary to secure the safety of the public.

10.Where work has been carried out without the provision of protective works, or where work on a building site has stopped or a building site has been abandoned, a local authority may require the site owner to carry out protective works.

0.13.1 Explanation

Regulation 13 requires that building sites are fenced off in such a way as to protect the public. It also provides powers to deal with building sites where work has for any reason ceased and the Health and Safety at Work etc. Act provisions are no longer applicable.

0.14 Clearing of footpaths

Regulation 14

Where any work is being carried out on a building site or building, any neighbouring footpath (including any footpath provided so as to form part of the protective works) shall be regularly cleaned and kept free of building debris and related materials by the person carrying out the work, to the satisfaction of the local authority.

0.14.1 Explanation

Regulation 14 requires the keeping free from mud or dust footpaths adjacent to building sites.

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Regulation 15

1.Subject to paragraph (2) a person carrying on work shall ensure that any building which is partly constructed or partly demolished or which has been completed but not yet occupied is, so far as reasonably practicable, properly secured or closed against unauthorised entry at all times when work thereon is not in progress.

2.Nothing in paragraph (1) shall apply to any work where the local authority is satisfied that adequate supervision of the building is being or will be maintained for the purpose of securing the building.

0.15.1 Explanation

Regulation 15 requires that all building sites where there are unfinished or partially complete works are kept safe and secure.

0.16 Relaxations

Regulation 16

No direction may be given under section 3(2) of the Act in relation to regulations 1 to 3, 5 and 7.

0.16.1 Explanation

Regulation 16 sets out the regulations that cannot be relaxed.

0.17 Continuing Requirements

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1.Subject to paragraph (2), the owners of buildings shall ensure that:

a.every air-conditioning system within a building is inspected at regular intervals, and

b.following each inspection of that system the owner of the building or, where the owner is not the occupier, the occupier is given a report containing the result of the inspection and including recommendations for the cost-effective improvement of the energy performance of that system.

2.This regulation shall not apply to:

a.air-conditioning systems with a total effective output rating of less than 12kW, or

b.air-conditioning systems solely for processes within a building.

3.In terms of Section 2 of the Building (Scotland) Act 2003 the provisions of paragraph (1) are a designated provision in respect of which there is a continuing requirement imposed on the owners of buildings.

0.17.1 Explanation

Regulation 17 requires the owners of an air-conditioned building to have such plant regularly inspected and to provide advice to the users of the building on related energy efficiency improvement work and how to operate the system efficiently. This regulation implements the terms of Articles 15 & 16 of Directive 2010/31/EU on the Energy Performance of Buildings (EPBD).

Scope - the regulation relates only to larger, fixed air-conditioning systems and does not cover portable systems. It also relates to comfort cooling of people in a building but does not cover any other system, such as cooling solely used in a manufacturing, trade or mechanical process. For example, a system only cooling computer equipment would be exempt.

The efficiency of the system should be assessed and the sizing compared to the cooling requirements of the building and appropriate advice given to the users of the building on possible improvement or replacement of the system and on alternative solutions.

0.17.2 Implementation

Continuing requirement - the regulation imposes a continuing requirement that means inspections are required not only throughout the life of a new building, but also for the life of an existing building, for as long as it has an air-conditioning system. The requirement to inspect systems in existing buildings was introduced in stages, starting with first inspection of all larger systems over 250kW by 4 January 2011, followed by first inspection of all remaining systems over 12kW by 4 January 2013.

0.17.3 Procedures to be followed

CIBSE Technical Memorandum 44 (TM44) 'Inspection of air conditioning systems' provides guidance on the regular inspection and assessment of air-conditioning systems and on the provision of advice and alternative solutions.

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Inspection frequency - for completely new air-conditioning systems, one way of meeting paragraph 1(a) of this regulation would be to make arrangements at completion for the first inspection. This should be carried out by an accredited expert no later than 5 years after the acceptance of the completion of commissioning of the system to Standard 6.7.

For existing systems over 12kW, one way of meeting paragraph 1(a) of this regulation would be to make arrangements for an inspection to be carried out by an accredited expert.

In all cases, the accredited expert doing the inspection has the discretion to set the frequency of inspections ranging from three years for poorly maintained and inefficient systems up to five years for those systems that are well maintained and demonstrate excellent levels of efficiency. In order to ensure compliance with the continuing requirement, the subsequent inspection should be carried out within the intervening time period.

The following issues should be considered in setting an inspection of systems more frequently than five years:

a.inefficiency of system

b.significantly oversized in relation to the cooling requirements

c.evidence that the design is not fit for purpose

d.evidence of poor installation

e.evidence of lack of maintenance

f.control system out of adjustment

g.age of system.

Size of systems - a number of individual systems each 12kW or less, but taken together totalling more than 12kW, within one building or fire-separated part of a building, would only qualify for inspection if they are linked by way of a central control.

New buildings - for new buildings, commissioning of building services including air- conditioning systems and the provision of written information shall be in accordance with Standards 6.7 and 6.8 respectively and guidance to these standards is provided in the Domestic and Non-domestic Technical Handbooks.

Accredited experts - inspections of existing air-conditioning systems should be carried out by accredited experts who are members of protocol organisations who are approved by Scottish Government to carry out such inspections.

Information on current protocol organisations can be found on the Building Standards Division web pages at www.scotland.gov.uk/epc

0.17.4 Provision of information to owners and occupiers

Following inspection of a system, the inspection report shall be issued by the member of the protocol organisation to the owner of the building. The inspection report shall contain the result of the inspection and include recommendations for the cost-effective improvement of the energy performance of the inspected system.

Where the owner of the building is not also the occupier, the owner should provide a copy of the report to the occupier.

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This guidance relates solely to duties imposed under Articles 15 & 16 of the Directive 2010/31/EU http://eur-lex.europa.eu/LexUriServ/LexUriServ.do? uri=OJ:L:2010:153:0013:0035:EN:PDF on the Energy Performance of Buildings. There are other separate legislative requirements for the inspection of air conditioning systems such as the F-Gas Regulations which are not dealt with in building regulations. However from an operational point of view, building owners should give consideration to the economic benefits of combining such inspections where appropriate.

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1.0 Introduction

1.0.1Background The

structure

of a building is fundamental to ensuring the safety of people in or around new and existing buildings and can be affected by a number of factors inside and outside the building including environmental factors. These factors should be considered to prevent the collapse, excessive deformation or the disproportionate collapse of buildings.

The climatic conditions in Scotland including temperature, snow, wind, driving rain and flooding and the impact of climate change should be carefully considered in the assessment of loadings (actions) and in the structural design of buildings.

The Standing Committee on Structural Safety (SCOSS) is an independent body supported by the Institution of Civil Engineers, the Institution of Structural Engineers and the Health and Safety Executive to maintain a continuing review of building and civil engineering matters affecting the safety of structures. The prime function of SCOSS is to identify in advance those trends and developments that might contribute to an increasing risk to structural safety. The collation and dissemination of information relating to matters of structural concern is a vital element of achieving safe structures. SCOSS has established a UK wide confidential reporting system (CROSS) to gather data on structural problems.

Appraisal of existing buildings - conversions to existing buildings present particular problems and an appraisal of the existing structure for its new occupation or use should be undertaken to ensure that appropriate measures are taken to meet the requirements of regulation 12. Guidance on how a structural appraisal may be undertaken is given in 'Appraisal of Existing Structures', 1996 published by the Institution of Structural Engineers.

Procurement - the contractual arrangements used by clients to procure a building can have important consequences for the reliability of the design and the adequacy of the construction. Frequently, building design procurement will involve the appointment of a number of designers who may be employed by more than one organisation. Detailed design of individual structural details and components can be passed to specialist contractors. In these circumstances the client should appoint a lead designer or other appropriately experienced and qualified person to oversee the design process.

1.0.2 Aims

The intention of this section is to ensure that the structure of a building shall be designed and executed in such a way that, during its intended life, it will not pose a threat to the safety of people in and around the building with an appropriate degree of reliability. To achieve a structure with adequate structural resistance, serviceability and durability the following should be taken into account:

a.the loadings (actions) on the building

b.nature of the ground

c.collapse or deformations

d.stability of the building and other buildings

e.climatic conditions

f.materials

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g.structural analysis, and

h.details of construction.

The actions on the building will comprise a set of loads applied directly to the structure that will include dynamic, concentrated and peak load effects, together with a set of imposed deformations caused for example by temperature changes or uneven settlement.

1.0.3 Latest changes

The following is a summary of the changes made to this section since 1 May 2009.

1.0.1reference to SCOSS updated

1.0.1reference to procurement added

1.0.2aims re-written to reflect Structural Eurocodes

1.0.4guidance on relevant legislation added for CDM regulations

1.0.6guidance on alternative approaches added including the use of withdrawn British Standards

1.0.8clause on certification introduced

1.1.1reference to guidance on fixings and stone masonry added

1.1.2reference to Structural Eurocodes added for loadings

1.1.3reference to Structural Eurocodes added for design and construction

1.1.4reference to BS EN 1997-2:2007 added for geotechnical investigation of the site

1.1.5reference to BS EN 1997-1:2004 added for design of foundations adjacent to existing buildings, and

1.2.1guidance in relation to disproportionate collapse updated to align with Structural Eurocodes

1.A. Annex A - list of structural Eurocodes and corresponding British Standards to be withdrawn added.

Minor alterations and corrections have also been made. A full list of changes to this edition of the Technical Handbooks is available on the Building Standards website.

1.0.4 Relevant legislation

The Construction (Design and Management) Regulations 2007 are intended to protect people working in construction and others who may be affected by their activities. The regulations require the systematic management of projects from concept to completion and throughout the life cycle of the structure, including eventual demolition. Clients have a duty to ensure that competent people are employed to do the work, that sufficient time is allocated for the work to be undertaken and that the various members of the design and construction teams co-operate and exchange information.

Safety of Sports Grounds Act 1975, Fire Safety and Safety of Places of Sport Act 1987 - in the case of sports grounds, reference should be made to the Guide to Safety at Sports Grounds (fifth edition 2008). The guide has no statutory force but many of its recommendations will be given force of law at individual grounds by their inclusion in safety certificates issued under either of the Acts referenced.

Guide to Safety at Sports Grounds (fifth edition 2008) - Chapter 4 and 14 of the Guide to Safety at Sports Grounds (fifth edition 2008) provides guidance on permanent and

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temporary structures at sports grounds and makes recommendations for designers to follow including minimising the risk of disproportionate collapse and designing stadia on the basis of risk assessments having regard to the likely hazards, for example, if the stadium is intended to be used as a venue for pop concerts.

Dynamic performance and testing of grandstands - in addition to normal static loads permanent grandstand structures must be designed to withstand the dynamic load arising from crowd action. Advice on the management and design of grandstand structures has been published by the Institution of Structural Engineers; “Dynamic Performance Requirements for permanent grandstands subject to crowd action December 2008”. This report recommends that the design team appointed for the design of a new grandstand or significant alteration to an existing grandstand should include an engineer who has the necessary knowledge and experience to oversee those aspects of the design concerned with dynamic crowd behaviour. The Institution of Structural Engineers maintains a list of suitably experienced engineers which can be found on the Institute’s website.

1.0.5 Alternative approaches

Where alternative approaches to the structural design are proposed other than using the guidance contained in this section, the structural design should take account of all of the factors identified in clause 1.0.2 above. For example, care should be taken where alternative numerical values are placed on factors of safety as this may have a detrimental effect on the overall stability of the structure.

The British Standards Institution (BSI) agreement with the European Committee for Standardisation (CEN) obliges it to withdraw UK national standards after a harmonised European Standard with the same scope and field of application has been produced. Withdrawal of a standard implies that while documents will still be available there will be no support or five-year review by a BSI committee to consider the currency of the standard and to decide whether it should be confirmed, revised or withdrawn. BSI, in line with this commitment, will be 31 March 2010 replace the British Standards relating to loading and structural design with the European Standards and associated National Annexes listed in Sections 1.1.2 and 1.1.3 of this guidance.

Whilst other guidance documents or international standards, including withdrawn national standards might be used in alternative approaches to satisfy building regulations, designers, verifiers, or in the case of certified projects, the approved certifiers of design (building structures) will need to satisfy themselves that the use of such guidance is appropriate for a specific project. Care should be exercised, particularly with withdrawn standards, in relation to wind and snow loadings (actions) where the effects of climate change may render these unsafe.

Where alternative approaches use design methods or codes other than those listed in this guidance then these must be used within the context of the assumptions set out in Section

1.1.3.Designs must be checked in order to deliver similar levels of design reliability.

Agricultural buildings - BS 5502: Part 22: 2003 provides an alternative approach to the design of buildings to be constructed solely for the purposes of agriculture. Designers using this approach must be satisfied that the reduced loads permitted by this standard are appropriate for the location of the building and for the intended use.

1.0.6 Temporary demountable structures

Temporary demountable structures are usually made from lightweight components and are used for a wide variety of functions at public and private events. They include grandstands, tents and marquees that can accommodate large numbers of people, and stages and supports for performers. A collapse of such a structure can have serious consequences. These structures are usually in place for a short time, generally no more than 28 days, and

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may not be covered by the requirements of regulations 8 to 12. The erection and use of many types of temporary structure will be controlled by the local authority.

Section 89 of the Civic Government (Scotland) Act 1982 requires that no person shall use or permit the use of a raised structure for seating or standing accommodation unless such use has been approved by the local authority. Certain raised structures are exempt from this including any structure that has been granted a building warrant.

The Institution of Structural Engineers has published guidance on the ‘Procurement, design and use of Temporary demountable structures’ (second edition 1999) such as grandstands, marquees and stage structures. Towers and masts to support media facilities are also included. The guidance is intended to assist event organisers, venue owners, local authorities, contractors and suppliers of demountable structures and for competent persons who are responsible for their design.

1.0.7 Annex

A list of structural Eurocodes and corresponding British Standards to be withdrawn is contained in Annex 1A.

1.0.8 Certification

Scottish Ministers can, under Section 7 of the Building (Scotland) Act 2003, approve schemes for the certification of design or construction for compliance with the mandatory functional standards. Such schemes are approved on the basis that the procedures adopted by the scheme will take account of the need to co-ordinate the work of various designers and specialist contractors. Individuals approved to provide certification services under the scheme are assessed to ensure that they have the qualifications, skills and experience required to certify compliance for the work covered by the scope of the scheme. Checking procedures adopted by Approved Certifiers will deliver design or installation reliability in accordance with legislation.

The Certification of Design (Building Structures) scheme has been approved by Scottish Ministers to confirm compliance with Standards 1.1 and 1.2. Details are available on the Building Standards Division website http://www.scotland.gov.uk/Topics/Built-Environment/ Building/Building-standards.

1.1 Structure

Mandatory Standard

Standard 1.1

Every building must be designed and constructed in such a way that the loadings that are liable to act on it, taking into account the nature of the ground, will not lead to:

a.the collapse of the whole or part of the building

b.deformations which would make the building unfit for its intended use, unsafe, or cause damage to other parts of the building or to fittings or to installed equipment, or

c.impairment of the stability of any part of another building.

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The loadings on the building will comprise actions that may be applied both separately and in various combinations.

The stability of a building and other existing buildings in the vicinity can be affected by ground conditions which should be investigated and assessed to ensure that the ground can safely support the building.

The collapse of the whole or part of a building is clearly a matter of the highest importance with respect to public safety. The design and construction of buildings should take into account all contributing factors such as loadings, climatic conditions, partial safety factors for materials and loadings, and design methodology to ensure that there is an acceptable probability that the building will not collapse (ultimate limit state) during its design lifetime.

Similarly deformations of buildings while not leading to an ultimate collapse can lead to public safety concerns particularly where they become unfit or unsafe for use. This can become apparent in several ways ranging from cracking, movement or springiness of floors, doors or windows not opening or closing, damage to pipes and other services within the building. The design and construction of a building should ensure that, by taking into account the factors set out above, the building does not fail in normal use (serviceability limit state).

The stability of existing buildings can be affected if the design and construction of a new building does not take into account any potential impacts on existing buildings. This could lead to a risk of collapse or damage to existing buildings with a consequent risk to public safety.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirements of this standard in so far as is reasonably practicable, and in no case be worse than before the conversion (regulation 12, schedule 6).

1.1.1 General

In order to be safe, a building should be capable of resisting all loads acting on it as a result of its intended use and geographical location. To achieve this, the structure of a building should be designed with margins of safety to ensure that the mandatory functional standard has been met.

In clause (b) of Standard 1.1 deformations are not intended to cover aesthetic damage such as shrinkage and other minor cracking.

Specialist advice from approved certifiers of design, chartered engineers or other appropriately qualified persons should be sought if the designer is in any doubt about the loads acting on a building or how these loads can be accommodated by the structure and safely transmitted to the ground.

Fixings - the SCOSS committee has expressed concern that safety critical fixings do not always receive the attention that they deserve. Fixings are important structural components. Designers must be satisfied that fixings receive the same consideration as other aspects of the design in terms of their selection, design, installation, inspection and testing. A SCOSS ALERT “The Selection and Installation of Construction Fixings” has been issued that can be found on the SCOSS website http://www.cross-structural- safety.org.

Stone Masonry - the Scottish Stone Liaison Group publication ‘natural stone masonry in modern Scottish construction’ provides guidance in the use of natural stone in new construction. Guidance includes information on stone and mortar selection, soiling of

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facades and design details for structures and moisture control http://www.scotland.gov.uk/ Topics/Built-Environment/Building/Building-standards.

1.1.2 Loading

Any reference to European Standards for Structure (Structural Eurocodes) in this section must be taken to include reference to the relevant UK National Annex.

The loadings to which a building will be subjected should be calculated in accordance with the appropriate Structural Eurocodes:

a.for densities, self-weight and imposed loadings, BS EN 1991-1-1: 2002 (Eurocode 1)

b.for snow loadings, BS EN 1991-1-3:2003 (Eurocode 1)

c.for wind loadings, BS EN 1991-1-4:2005 (Eurocode 1)

d.for earth retaining structures, BS EN 1997-1:2004 (Eurocode 7)

e.any greater loadings to which the building is likely to be subjected.

1.1.3 Design and construction

Any reference to European Standards for Structure (Structural Eurocodes) in this section must be taken to include reference to the relevant UK National Annex.

The structural design and construction of a building should be carried out in accordance with the following Structural Eurocodes:

a.for foundations, BS EN 1997-1:2004 (Eurocode 7)

b.for structural work of reinforced, prestressed or plain concrete, BS EN 1992-1-1:2004 (Eurocode 2)

c.for structural work of steel, BS EN 1993-1-1:2005 (Eurocode 3)

d.for structural work of cold form, thin gauge steel members and sheeting BS EN 1993-1-3:2006 (Eurocode 3)

e.for structural work of composite steel and concrete construction, BS EN 1994-1-1:2004 (Eurocode 4)

f.for structural work of aluminium, BS EN 1999-1-1:2007 (Eurocode 9)

g.for structural work of masonry, BS EN 1996-1-1:2005 or BS EN 1996-3:2006 Simplified calculation rules for masonry structures (Eurocode 6)

h.for structural work of timber, BS EN 1995-1-1:2004 (Eurocode 5)

i.for earth retaining structures BS EN 1997-1:2004 (Eurocode 7).

The reliability of designs carried out in accordance with these codes is based on a number of assumptions set out in BS EN 1990:2002 that include:

•the choice of the structural system and the design of the structure is made by appropriately qualified and experienced personnel

•the design and construction is carried out by personnel having the appropriate skill and experience

•adequate supervision and quality control is provided during execution of the work

•the construction materials and products are used as specified in BS EN 1990 or in BS EN 1991 to BS EN 1999 or in the relevant execution standards, or reference material or product specifications

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•the structure will be adequately maintained, and

•the structure will be used in accordance with the design assumptions.

Those responsible for procuring the design and construction of buildings based on Structural Eurocodes should be aware of these assumptions and should ensure that they have employed individuals with the necessary qualifications, skills and experience and that appropriate procedures for checking designs have been adopted.

1.1.4 Nature of the ground

The foundations of buildings should be designed to sustain and transmit the loadings to the ground in such a manner that there will be no ground movement which will impair the stability of the building. All aspects of the nature of the ground should be taken into consideration including ground movement caused by:

•swelling, shrinkage or freezing of the subsoil, or

•landslip, or

•subsidence such as that arising from the collapse of abandoned mineral workings or quarrying operations.

There may be known or recorded conditions of ground instability, such as that arising from landslides, disused mines or unstable strata which, if ignored, could have an adverse effect on a building. Such conditions should be taken into account in the design and construction of the building and its foundations.

Attention is drawn to Planning Policy Guidance Note 14 (PPG 14) Development on unstable land www.communities.gov.uk. Although PPG 14 contains specific reference to England & Wales, it does set out the broad planning and technical issues relating to development on unstable land.

Information on the scale and nature of problems arising from mining instability, natural underground cavities and adverse foundation conditions is available from the following:

•British Geological Survey, Murchison House, West Mains Road, Edinburgh, EH9 3LA http://www.bgs.ac.uk

•The Coal Authority, 200 Lichfield Lane, Mansfield, Nottinghamshire, NG18 4RG http:// www.coalminingreports.co.uk

Information can also be obtained from local authorities that hold Building Standards Registers and other relevant records.

Where new foundations are to be constructed or existing foundations altered it will generally be necessary to undertake a geotechnical investigation of the site. This should be carried out using the methods described in BS EN 1997-2: 2007.

1.1.5 Stability of existing buildings

The stability of existing buildings may be affected by a new building located in their vicinity. Care must be taken to avoid undermining the foundations or otherwise affect the stability of existing buildings. The design of foundations adjacent to existing buildings should be carried out in accordance with the recommendations of BS EN 1997-1:2004.

Factors that can also affect the stability of an existing building and should be taken into account include:

•additional or new loads arising from the construction of the new building

•increased or new wind loads arising from the construction of the new building

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•pressure bulb extending below existing building

•changes in groundwater level

•loss of fines during pumping operations or climatic conditions.

1.2 Disproportionate Collapse

Mandatory Standard

Standard 1.2

Every building must be designed and constructed in such a way that in the event of damage occurring to any part of the structure of the building the extent of any resultant collapse will not be disproportionate to the original cause.

1.2.0 Introduction

All buildings must be designed to accommodate unforeseen or accidental actions in such a way as to prevent the extent of any resulting collapse being disproportionate to the cause of the collapse. Buildings should be designed so that they are robust which is defined in BS EN-1991-1-7:2006 as the ability of a structure to withstand events like fire, explosions, impact or the consequences of human error without being damaged to an extent disproportionate to the original cause.

Explanation of terms. Nominal length of load-bearing wall construction should be taken as:

•in the case of a reinforced concrete wall, the distance between lateral supports subject to a length not more than 2.25 x storey height

•in the case of an external masonry wall, or timber or steel stud wall, the length measured between vertical lateral supports

•in the case of an internal masonry wall, or timber or steel stud wall, a length not more than 2.25 x storey height.

Storey height is the distance from the underside of one floor to the underside of the floor immediately above.

Key element is a structural member upon which the stability of the remainder of the structure depends and should be capable of sustaining an accidental design loading of 34kN/m² applied in the horizontal and vertical directions (in one direction at a time) to the member and any attached components such as cladding, having regard to the ultimate strength of such components and their connections. Such accidental design loading should be assumed to act simultaneously with 1/3rd of all normal characteristic loading.

Load bearing wall construction - includes masonry cross-wall construction and walls comprising close centred timber or lightweight steel section studs.

Educational building is any building used for educational purposes including kindergartens, schools, colleges and university buildings.

Buildings accessible to the general public is intended to include buildings where members of the public can enter during normal opening hours and are allowed to access all parts of the building, other than those parts restricted to staff only.

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Fire - the protection to be afforded to the structure of a building when it is exposed to the action of fire is dealt with by mandatory Standard 2.3. The guidance within Section 2 refers to relevant codes that should be used for the design of the structure in a fire.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirements of this standard in so far as is reasonably practicable, and in no case be worse than before the conversion (regulation 12, schedule 6).

1.2.1 Disproportionate collapse

A building which is susceptible to disproportionate collapse is one where the effects of accidents and, in particular, situations where damage to small areas of a structure or failure of single elements could lead to collapse of major parts of the structure.

Buildings should be provided with a level of robustness by adopting the principles of risk analysis, categorising buildings, taking into account both the risk of the hazard and its consequences and providing additional measures commensurate to the level of risk and consequences of such collapse of the building. The risk level and accidental actions that should be considered when undertaking the structural design of a building for disproportionate collapse should be in accordance with the recommendations of BS EN 1991-1-7:2006 or the method set out below.

Any reference to European Standards for Structure (Structural Eurocodes) in this section must be taken to include the relevant UK National Annex.

To ensure that buildings are designed and constructed to sustain a limited extent of damage or failure without a disproportionate level of collapse from an unspecified cause, the following procedure should be followed:

•determine building risk group

•assess additional measures

•design and construct additional measures.

1.2.2 Determine building risk group

The issues to be considered with respect to assessing the risk group of a building are its occupancy level, use, the number of storeys and floor areas.

The risk of an extreme event such as an explosion or other incident occurring would not be decreased simply by providing these measures and there is no certainty that demolition or building alteration would be carried out in accordance with good practice but the consequences of such an incident occurring would be considerably reduced.

Table 1.1 Determine building risk group

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Notes.

1.Agricultural and related buildings unless exempt under clauses 7 and 8 of Schedule 1 of the Building (Scotland) Regulations 2004.

2.Hotels in risk group 2A have been identified separately from residential buildings.

3.Educational buildings in risk groups 2A and 2B have been identified separately from assembly buildings.

4.For the purposes of this table where the gallery area:

•is not more than 20% of the plan area of the building or 20m² whichever is the less then it should be ignored for the purposes of calculating the storey area

•is more than 20% but not more than 50% of the plan area of the building or 20m² whichever is the less then the floor area of the gallery should be added to the floor area in calculating the floor area

•is more than 50% of the plan area of the building then the gallery should be considered to be a separate storey in calculating the number of storeys.

The nomenclature of the risk groups 1, 2A, 2B and 3 are synonymous with the consequence classes in Table A.1 – Categorisation of consequence classes of BS EN 1991-1-7: 2006.

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In determining the number of storeys in a building, basement storeys may be excluded provided such basement storeys fulfil the robustness of risk group 2B buildings.

For buildings intended for more than one type of use the risk group should be that pertaining to the most onerous risk group.

1.2.3 Assess additional measures

The additional measures which should be provided vary extensively according to building type and use and the actual measures should be designed in accordance with the relevant sections of design codes. For example, high rise hotels or flats or assembly buildings or grandstands require a different level of robustness than low rise buildings or storage buildings.

The additional measures which should be applied to buildings of the risk groups derived from the above table are set out below:

Risk Group 1 buildings - no additional measures are likely to be necessary when the building has been designed and constructed in accordance with the rules given in this Technical Handbook, or other guidance referenced under Section 1, for complying with Standard 1.1 in normal use.

Risk Group 2A buildings - provide effective horizontal ties, or effective anchorage of suspended floors to walls, for framed and load-bearing wall construction.

Risk Group 2B buildings - provide effective horizontal ties for framed and load-bearing wall construction, together with effective vertical ties, in all supporting columns and walls.

Alternatively, check that upon the notional removal of each supporting column and each beam supporting one or more columns, or any nominal length of load-bearing wall (one at a time in each storey of the building) the building should remain stable and that the area of floor at any storey at risk of collapse should be not more than 15% of the floor area of that storey or 100m², whichever is the less and does not extend further than the immediate adjacent storeys (see diagram below).

Where the notional removal of such columns and lengths of walls would result in an extent of damage in excess of the above limit, then such elements should be designed as ‘key elements’.

Figure 1.1 Floor collapse limit

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Risk Group 3 buildings - a systematic risk assessment of the building should be carried out, taking into account all the normal hazards that can be foreseen as far as possible together with any abnormal hazards.

Critical situations for design should be selected that reflect the conditions that can be foreseen as far as possible during the life of the building.

The structural form and concept and any protective measures should then be chosen and the detailed design of the structure and its elements undertaken in accordance with the recommendations in the codes and standards in clause 1.2.4.

1.2.4 Design and construct additional measures

The structural design and construction to take account of the additional measures including horizontal and vertical ties where appropriate and checking the integrity of the building following the notional removal of vertical members and the design of key elements, should be carried out in accordance with the design recommendations contained in Annex A of BS EN 1991-1-7:2006.

1.2.5 Other sources of guidance

More detailed information has been produced by organisations on disproportionate collapse as follows:

a.Technical Guidance Note – ‘The Building Regulations 2004 Edition – England and Wales Requirement A3 – Disproportionate Collapse’, National House Building Council (NHBC)

b.Technical Bulletin Number 3 ‘Design Guidance for Disproportionate Collapse’, UK Timber Frame Association

c.‘Masonry Design for Disproportionate Collapse Requirements under Regulation A3 of the Building Regulations (England & Wales)’, Brick Development Association

d.'Guidance on meeting the Robustness Requirements in Approved Document A', Steel Construction Institute

e.'How to design concrete buildings to satisfy disproportionate collapse requirements'. http://www.concretecentre.com/

The above guidance is based on England & Wales Regulation A3 and should be interpreted in relation to Standard 1.2. In particular, references to building classes should be risk groups and the building types and occupancy should be interpreted as the building types set out in the table to clause 1.2.2.

Annex 1.A Structural Design Standards

1.A.0 Introduction

The British Standards Institution (BSI) agreement with the European Committee for Standardisation (CEN) obliges it to withdraw UK national standards after a harmonised European Standard with the same scope and field of application has been produced. BSI, in line with this commitment, will by 31 March 2010 replace the British Standards relating to loading and structural design with the European Standards and associated National Annexes listed in the tables below:

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Table 1.2 Eurocode: Basis of structural design

Table 1.3 Eurocode 1: Actions on structures

Table 1.4 Eurocode 2: Design of concrete structures

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Table 1.5 Eurocode 3: Design of steel structures

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Table 1.6 Eurocode 4: Design of composite steel and concrete structures

Table 1.7 Eurocode 5: Design of timber structures

Table 1.8 Eurocode 6: Design of masonry structures

Table 1.9 Eurocode 7: Geotechnical design

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Table 1.10 Eurocode 8: Design of structures for earthquake resistance

Table 1.11 Eurocode 9: Design of aluminium structures

Additional Information. Note 1: Many of these standards are not directly, or are not currently referenced in Section 1: Structure. Some may not be applicable to Section 1 Structure such as, BS 5400 for bridges, or are applicable to other parts of the technical handbooks.

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2.0 Introduction

2.0.1Background Life safety is the paramount objective of

fire

safety. Non-domestic buildings should be designed and constructed in such a way that the risk of fire is reduced and if a fire does occur, there are measures in place to restrict the growth of fire and smoke to enable the occupants to escape safely and fire-fighters to deal with fire safely and effectively.

There are more than 2000 reported fires in non-domestic buildings every year in Scotland. The most common cause of accidental fires in non-domestic buildings is faulty appliances, accounting for more than 20% of fires followed by cooking at around 16%. Statistics also show that around 24% of fires in non-domestic buildings are deliberately started. While the number of deaths from fires in non-domestic buildings is less than domestic buildings the potential for significant life loss and injuries is far greater. This is due to large occupancy capacities, building complexity, occupant capability and behaviour including the potential for delay in occupant evacuation following the outbreak of fire.

In the event of an outbreak of fire, it is important that the occupants are warned as soon as possible. The guidance to Standard 2.11 provides recommendations for the installation of alarm and detection systems in buildings where people may be asleep or where there is a particularly high risk.

The standards and guidance in this section are designed to work together to provide a balanced approach to fire safety. The building elements, materials, components or other parts of the building identified in the guidance should follow the appropriate performance levels that are recommended throughout the guidance. However where an element, material, component, or other part of a building is covered by more than one standard, the more demanding guidance should be followed in most cases.

2.0.2 Aims

The purpose of the guidance in Section 2 is to achieve the following objectives in the case of an outbreak of fire within the building:

•to protect life

•to assist the fire and rescue services, and

•to further the achievement of sustainable development.

Protection of life - it is important to recognise that the standards will not guarantee the life safety of all building occupants. Occupants in buildings do not normally perceive themselves to be at risk from fire and are not usually aware of the speed that fire can spread. The risk to occupants is greater if they are asleep during the outbreak of fire as they are likely to be roused more slowly. Occupants should be warned as soon as possible following the outbreak of fire and the guidance to Standard 2.11 provides recommendations for the installation of alarm and detection systems in non-domestic buildings.

Fire and rescue service - in some cases, occupants will not react quickly enough before being overcome by the effects of the fire and smoke and as a result, may require to be rescued by the fire and rescue service. For facilities to assist the fire and rescue service, see Standards 2.12 to 2.14.

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Sustainability - the building regulations are primarily concerned with the protection of people from the dangers inherent in buildings, rather than protecting the owners of buildings from any economic loss which might occur. However following the guidance in the handbook will continue to embed active and passive fire protection systems within buildings which should reduce the likelyhood of the total destruction of the building following the outbreak of fire.

2.0.3 Scope

Guidance in this section may not be appropriate for the following buildings as they are rarely designed and constructed in Scotland:

•buildings with a storey at a height of more than 60m

•enclosed shopping centres with malls on 3 or more storeys, and

•air supported structures.

In such cases, the alternative approach as described in clause 2.0.7 should be followed.

In the case of a mixed use building containing non-domestic and domestic accommodation, reference should be made to the Technical Handbook for domestic buildings as well as the guidance contained in this Handbook.

2.0.4 Method of measurement

The rules of measurement in Section 0 of the Technical Handbook may not be appropriate for the guidance in Section 2 Fire. For example, to establish the height of the topmost storey for fire and rescue service facilities, the height should be measured from the fire and rescue service access level and not necessarily the lowest ground level. Therefore, methods of measurement unique to fire are described within the guidance under each of the relevant standards.

The following guidance on measurements are unique to Section 2 Fire of the Handbooks and where appropriate, should be read in conjunction with the measurements specified in schedule 4 to regulation 7 as set out in Section 0 General.

Plant storeys - for the purpose of measuring the height above ground to the top most storey of a building, roof-top plant areas and any top storeys consisting solely of plant rooms, should be excluded.

An openwork floor is a floor with an open mesh decking which allows smoke to pass through. It is common to construct multi-level openwork floors around high bay racking systems. In such cases, the total storey area should be taken to be the total area of all openwork floors within that storey, including the floor area taken up by the racking system. Therefore, each level should be measured independently to the innermost surface of the enclosing walls and then added together to give the total storey area.

The area of:

a.a compartment should be taken to be the total floor area of all storeys within that compartment

b.an enclosed shopping centre with a mall should be taken to be the total floor area of all storeys within that enclosed shopping centre

c.a storey should be taken to be the total area of all floors within that storey, including the floor area of any gallery or openwork floor.

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The key changes that have been made to the standards and guidance applicable from 1 June 2022 are:

•General – Minor editorial change to refer to fire resistance duration throughout.

•Clause 2.0.9 – Clause re-written to include reference to European Classification F and further explanation provided in annex 2.E.

•Clause 2.0.10– Guidance on third party certification and accreditation re-written to add clarity.

•Clause 2.1.0 – Last sentence removed in third paragraph.

•Clause 2.1.12 – Typographical error in first sentence.

•Clause 2.2.7 – Minor editorial changes.

•Clause 2.1.15 – Additional guidance provided on junctions with walls.

•Clause 2.4.0 – Cross reference to Standard 2.1 compartmentation and Standard 2.2 separation included in third paragraph.

•Clause 2.4.1 – minor editorial changes to clarity intent.

•Clause 2.4.2 – European Class F products added to guidance on dividing cavities.

•Clause 2.4.6 – Guidance clarified to include the amended Regulation 8 of the Building (Scotland) Amendment Regulations 2022.

•Clause 2.4.9 – Guidance on junctions amended to clarify intent.

•Clause 2.5.0 – Reference to prohibition on the use of highly combustible metal composite material panels added.

•Clauses 2.6.0 - Reference to the prohibition on the use of highly combustible metal composite material panels added and previous guidance removed.

•Clause 2.6.4 – First paragraph replaced, minor editorial changes and guidance changed in accordance with Regulation 8 of the Building (Scotland) Amendment Regulations 2022.

•Clause 2.6.6 - Minor editorial changes.

•Standard 2.7 – Mandatory standard amended to clarify intent with regard to the height, use and position of the building.

•Clause 2.7.0 – Reference to the prohibition of highly combustible metal composite cladding material panels added. Cross reference made to Standard 2.1 Compartmentation and Standard 2.2 Separation. Advice on compliance provided under the Building Standards Futures Board.

•Clause 2.7.1 – Meaning of external wall cladding systems explained, clause re-written and Table 2.9 amended to include Regulation 8 of the Building (Scotland) Amendment Regulations 2022.

•Clause 2.7.2 – Guidance amended to include Regulation 8 of the Building (Scotland) Amendment Regulations 2022 and additional guidance on awnings, canopies and signage provided.

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•Clause 2.D.4 – Reference to BR 128 removed.

•Clause 2.E.0 – Reference to the Construction Products Regulations removed.

•Clause 2.E.1 – Clause re-written to provide additional guidance on external wall cladding systems including exemptions and the use of large scale fire testing.

•Clause 2.E.2 – European Class A updated and Class F reintroduced to table. Guidance provided on smoke production and burning droplets.

•Clause 2.E.3 – Reference to Classified Without Testing process updated.

•Appendix A: New Regulation 8 definitions included for highly combustible metal composite material, relevant building, specified attachment and substantial layer. Hospital definition amended.

•Appendix B: References to BS 8414/BR 135 and BS 9414 added. Reference to the publication ‘Guide to Undertaking Technical Assessments of Fire Performance of Construction Products Based on Fire Test Evidence’ (Passive Fire Protection Forum, 2021) added.

2.0.6 Explanation of terms

Buildings accessible to the general public is intended to include buildings where members of the public can enter during normal opening hours and are allowed to access all parts of the building, other than those parts restricted to staff only.

Protected routes of escape - throughout the document there are references to protected routes of escape these include: escape routes in a central core, fire and smoke control in corridors, flat roofs, access decks, galleries with rooms enclosed below, openings in floors, places of special fire risk, protected lobbies, protected zones, rooms, toilets and washrooms in protected zones, external escape stairs, escape stairs in basements and auditoria. This list is not exhaustive and is not intended to cover all parts of a building providing protected routes of escape. For example, compartment walls and compartment floors also protect routes of escape but are covered by the guidance to Standard 2.1.

External areas - a roof, an external balcony, or an enclosed courtyard open to the external air, where the area is more than 8m² and to which there is access for a purpose other than maintenance, should be regarded as a room.

Circulation areas in non-domestic buildings include unprotected zones or areas in a room or space which provide access to an exit and may be permanently demarcated from any space intended for human occupation.

2.0.7 Alternative approaches

Alternative means of complying with building standards – the guidance contained within this Technical Handbook indicates one or sometimes more than one means of complying with the mandatory building standards 2.1 to 2.15. In the majority of projects it is envisaged that meeting the guidance will be the usual means of showing that compliance with the building standards has been achieved.

However, it should be appreciated that, due to the generic nature of the guidance it cannot cover all building designs or, for example, innovative or new methods of construction. In such cases the designer or engineer will be required to show, by alternative means, that compliance with the building standards will be achieved in the completed building. For example, where the elements of structure are engineered timber (including cross laminated timber), the structure should maintain stability during the fire growth and fully developed post flashover phases of the fire without reliance on intervention from the fire

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and rescue services. Encapsulation of combustible elements of structure may require to be provided to protect the structure against ignition and charring for the duration of the fire. Where encapsulation (i.e. both physically and in terms of the period of fire resistance duration) is not provided or does not protect the combustible material against ignition and charring for the duration of the fire, the structural fire engineer should consider the additional contribution of the exposed combustible material to the fire load density including an assessment of the structural stability of the building due to both potential delamination and failure of the fixings at elevated temperatures.

Fire safety engineering - it is reasonable to demonstrate compliance with the functional standards by alternative means and in such cases, the fire engineer, the building standards verifier and the fire and rescue service should be consulted early in the design process.

Fire safety engineering may be the only practical way to achieve a satisfactory level of fire safety in some large and complex buildings or where innovative or new methods of construction are used. In such cases a holistic approach is desirable from first principles rather than following, in part or wholly, the guidance contained in the Technical Handbooks. In such cases the building standards verifier and the fire and rescue service should be consulted as part of the Qualitative Design Review (QDR) process.

For many projects it is likely that designers will follow the guidance in the Technical Handbooks and fire engineering techniques will not be necessary. In its simplest form the QDR team may define the acceptance criteria in terms of compliance with the Handbooks.

However, it is common for fire engineers and regulators to be engaged relatively late in the design process to resolve fire safety issues raised during the verification or, in extreme cases, the construction process. This is unhelpful as fire engineers are often commissioned to resolve specific issues where the design does not follow the guidance rather than assessing the building holistically. This can lead to a comparative exercise against unrealistic worse case scenarios of a “code compliant” design to justify deviations. This is not the intent of the guidance and it is important that the safety goals are well defined and achieved with a sufficient margin of safety. The objective of a comparative study should be to demonstrate that the building design, as a whole, presents no greater risk to the occupants than a similar type of building designed in accordance with the Technical Handbook guidance. Further, it is common for the inappropriate use of Computational Fluid Dynamics where the deviations from the Handbooks would not merit such an exercise to be carried out. It is recognised that there may be instances where small deviations from the guidance do not warrant a “whole building” fire engineered design and inevitably involves a degree of negotiation without the need for detailed analysis.

Not all cases of variance from the guidance will require the appointment of a fire engineer. Reference could be made to ‘A simplified approach to alternative fire safety strategies’ Scottish Government (2010), which provides additional advice.

Existing buildings - it may be appropriate to vary the guidance contained in this Handbook when assessing the guidance against the constraints in existing buildings, especially those buildings which are listed in terms of their architectural or historic interest. In such cases, it would be appropriate to take into account a range of fire safety features, some of which are dealt with in this Handbook and some of which are not addressed in any detail. For more detailed information, guidance is contained in the ‘Guide for Practitioners 6

–Conversion of traditional buildings’ (Historic Scotland).

Fire engineering designs can be complex and many require extensive use of engineering judgement. The following documents are cited to ensure that the guidance given encompasses best practice worldwide:

•BS 7974: 2019 Application of fire safety engineering principles to the design of buildings, or

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•International Fire Engineering Guidelines, 2005 (IFEG).

The use of either document assumes that those carrying out or assessing a fire engineering approach have sufficient technical training, knowledge and experience to understand fully the risks involved.

The objectives of any fire safety strategy should be established first and designers and verifiers should be aware of the importance of the design assumptions. For example, the strategy should include an assessment of the system reliability. This will help to ensure that the fire safety objectives have been met.

Responsible person - it is important that owners/responsible person understand that the fire safety measures installed in a building need to be maintained and tested over the life time of the building so that they will operate effectively. BS 7974 and IFEG assume that all aspects of the fire engineering strategy are capable of being maintained and deployed over the lifetime of the building. If for example, alterations are found to be necessary due to changes to the building layout, the original strategy may need to be re-evaluated to ensure the fire safety provisions have not been compromised. For this reason, the fire strategy should preferably support any fire safety risk assessment required under Part 3 of the Fire (Scotland) Act 2005, as amended.

Fire safety engineering involves the use of scientific based calculations and/or statistical information to demonstrate an adequate level of safety for a specific building, structure or installation. In this regard the fire safety strategy is based on performance rather than prescription. Therefore, fire safety engineering is about the need to identify the fire hazard, assess the fire risks, understand the consequences and to offer fire safety strategies and designs to show how the objectives have been met. The ‘tools’ that support fire engineering can include calculation methods, which are used to demonstrate that under a worst reasonable case, tenable conditions are maintained during the evacuation period. For example, a smoke exhaust fan in a smoke reservoir within an atrium space fails to operate but the smoke layer height continues to be maintained by the activation of a stand- by fan.

It is recognised that fire engineering is still a rapidly developing field and as such does not have the standardised codes for approaching and solving problems compared to other engineering disciplines. The documents identified above aim to provide a structured framework for assessing the interaction between, buildings, people and fire, and to facilitate innovation in design without compromising safety. They provide information on how to undertake a detailed analysis of specific aspects of fire safety engineering in buildings.

In practice, both frameworks provide a flexible but formalised engineering approach to fire safety which can be applied to new or existing buildings to show that the functional standards have been met.

BS 7974: 2019 Application of fire safety engineering principles to the design of buildings is supported by 7 published documents:

•Part 1: Initiation and development of fire within the enclosure of origin

•Part 2: Spread of smoke and toxic gases within and beyond the enclosure of origin

•Part 3: Structural response and fire spread beyond the enclosure of origin

•Part 4: Detection of fire and actuation of fire protection systems

•Part 5: Fire service intervention

•Part 6: Human factors: Life safety strategies – Occupant evacuation, behaviour and condition, and

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•Part 7: Probabilistic risk assessment.

International Fire Engineering Guidelines (IFEG) have been developed for use in the fire engineering design and approval of buildings. The objectives of the guidelines are to provide:

a.a link between the regulatory system and fire engineering

b.guidance for the process of engineering, and

c.guidance on available methodologies.

The IFEG sub-systems bear a very close resemblance to the subsystems used in BS: 7974: 2019 and are set out below:

•fire initiation and development and control

•smoke development and spread and control

•fire spread and impact and control

•fire detection, warning and suppression

•occupant evacuation and control, and

•fire services intervention.

Clause 1.3.2 of IFEG states that “Typically, each building project is unique and similarly, each fire engineering evaluation is unique". It is not sensible, therefore, to set down detailed guidance on how the fire safety analysis should be undertaken. Instead, it is the responsibility of the fire engineer to plan the analysis for the particular project, based on the decisions taken during the preparation of the fire engineering brief as discussed in Chapter 1.2.

Places of lawful detention for example prisons, secure accommodation and mental health premises, present particular problems owing to the obvious difficulties of providing both the level of security required and effective means of evacuation in the event of fire. Due to the constraints this can place on the design it may be necessary to vary from the guidance contained in this section of the Technical Handbook. In some cases it may be necessary to use fire safety engineering as part of such an alternative approach having evaluated the full range of fire safety features proposed to control the risk and the potential consequences of a fire.

2.0.8 Relevant legislation

It is important to be aware that there is other legislation, apart from building regulations, imposing requirements for means of escape in case of fire and other fire safety measures. It is therefore recommended that consultation with those responsible for such legislation takes place before the application for building warrant is finalised. Any necessary fire safety measures requiring building work can then be included in the application.

Part 3 of the Fire (Scotland) Act 2005 (2005 Act), as amended introduced a fire safety regime which applies to non-domestic buildings. The regime does not generally apply to domestic buildings but may apply where staff are employed or members of the general public have access e.g. a dental surgery within a dwelling. The regime will also apply to domestic buildings which are licensed as Houses in Multiple Occupation and to some domestic buildings where certain care services are provided. Those domestic premises covered by Part 3 of the 2005 Act are defined in section 78 of the Act.

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Persons with obligations under the Act are required to carry out a fire safety risk assessment which may require additional fire safety precautions to reduce the risk to life in case of fire. For example, measures to reduce the risk and spread of fire, means of escape, fire-fighting equipment, fire detection and warning, instruction and training. Other measures are prescribed by regulation. The fire safety risk assessment should be kept under continuous review.

There is (sector specific) guidance for various building types on how to comply with Part 3 of the Act on the Firelaw website.

In many premises, existing fire safety measures have been incorporated in accordance with building regulations however it is possible for a higher standard to be applied as a consequence of a fire safety risk assessment.

Section 71 of the 2005 Act makes it clear that terms, conditions or restrictions in licences,

including statutory certification or registration schemes, are to have no effect if they relate to fire safety requirements or prohibitions which are or could be imposed under Part 3 of the 2005 Act.

The Fire Safety (Scotland) Regulations 2006 made under the Fire (Scotland) Act 2005 contain provisions which are part of the fire safety regime. These regulations must be considered along with Part 3 of the 2005 Act. The regulations contain further requirements in respect of fire safety risk assessment and obligations of duty holders.

Section 70 of the Fire (Scotland) Act 2005 restricts the application of Part 1 of the Health

and Safety at Work Act 1974 and any regulations or orders made under it in relation to general fire safety. There are exceptions; firstly where a single enforcing authority enforces both pieces of legislation and secondly, in respect of sites where the Control of Major Accident Hazards Regulations 1999 (COMAH) apply.

The Management of Health and Safety at Work Regulations 1999 require all employers to assess the risks to workers and any others who may be affected by their work or business. The objective is to identify preventative and protective measures and implement corrective action as appropriate. However in general, these regulations do not apply to general fire safety by virtue of the restriction in section 70 of the Fire (Scotland) 2005 Act.

The Health and Safety (Safety Signs and Signals) Regulations 1996 impose requirements in relation to fire exit and directional signs. In addition, the Fire (Scotland) Regulations 2006 requires emergency routes and exits to be indicated by signs. Advice on fire safety signs is given in the HSE publication, ‘Safety signs and signals: Guidance on Regulations – The Health and Safety (Safety Signs and Signals) Regulations 1996’. Guidance is also available in BS ISO 3864-1-2011 and BS 5499: Part 4: 2013 on graphical symbols, fire safety signs and escape route signing.

The Construction (Design and Management) Regulations 2015 is intended to protect people working in construction and others who may be affected by their activities. The regulations require the systematic management of projects from concept to completion and throughout the life cycle of the structure, including eventual demolition. The CDM Regulations require designers and those who control or carry out construction work to identify hazards associated with their designs or work (including risk from fire) and plan to eliminate, reduce or control the risks.

Dangerous Substances and Explosive Atmospheres Regulations 2002 require the risks from substances with flammable, explosive or oxidising properties to be properly controlled. This can include particular requirements in respect of design and construction in which substances are present or in the vicinity. The regulations are enforced by the HSE, or for certain types of premises, the local authority. In general, these regulations do not apply to general fire safety as a result of similar provisions being imposed by the Fire Safety (Scotland) Regulations 2006.

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Sports Grounds - When designing or verifying sports grounds, it is appropriate to use the guide to Safety at Sports Grounds http://www.culture.gov.uk/. The guide has no statutory force but many of its recommendations will be given force of law at individual grounds by their inclusion in safety certificates issued under the Safety of Sports Grounds Act 2011 or the Fire Safety and Safety of Places of Sport Act 1987.

The Safety of Sports Grounds Act 1975 is amended by Article 7 of the Fire (Scotland) Act 2005 (Consequential Modifications and Savings) Order 2006 so that a condition of a safety certificate for a sports ground may not require a person to contravene Part 3 of the 2005 Act or regulations made under it and requires the local authority to amend such a certificate if it would have that effect.

The Fire Safety and Places of Sports Act 1987 is amended by Article 13 of the Fire (Scotland) Act 2005 (Consequential Modifications and Savings) Order 2006 so that a condition of a safety certificate for a regulated stand may not require a person to contravene Part 3 of the 2005 Act or regulations made under it and requires the local authority to amend such a certificate if it would have that effect.

The Civic Government (Scotland) Act 1982 contains provisions for public entertainment licences. Similarly to liquor licences, the appropriate bodies are consulted before a licence is granted. The Act has been amended by the Fire (Scotland) Act 2005 (Consequential Modifications and Savings) Order 2006 to prevent fire safety conditions being imposed where Part 3 of the Fire (Scotland) Act 2005, as amended applies.

Houses in Multiple Occupation (HMOs) – Section 2 Fire of the Domestic Technical Handbook should be used for multi-occupancy dwellings designed for not more than six individuals living together as a single household. This includes houses, maisonettes and flats (including flatted student accommodation and cluster flats that are essentially designed as self-contained flats), regardless of the evacuation strategy. Section 2 Fire of the Non-domestic Technical Handbook should be used for shared multi- occupancy residential buildings designed for more than six individuals including student accommodation designed on the traditional "halls of residence" principle, with bedrooms having shared sanitary and cooking facilities.

It should be noted that multi-occupancy dwellings and shared multi-occupancy residential buildings may also require to be licensed for use as a ‘House in Multiple Occupation’ (HMO) under the Civic Government (Scotland) Act 1982 (Licensing of Houses in Multiple Occupation) - Order 2000. In relation to fire safety aspects, HMOs which require a licence are also subject to Part 3 of the Fire (Scotland) Act 2005, as amended, and guidance is available on the Firelaw website.

The Care Inspectorate is responsible for regulating a diverse range of care services some of which are delivered in non-domestic buildings (e.g. care homes, nurseries, independent hospitals, hospices, residential schools and secure accommodation) and some in domestic buildings (e.g. childminding, supported accommodation and adult placement services). The services are inspected by the Inspectorate against national care standards issued by Scottish Ministers some of which include physical standards for the premises. The Inspectorate consults with the fire and rescue service on fire safety matters as part of the care service registration process. Where the applicant for a warrant intends to use or provide such a service, they should consult the Inspectorate and fire and rescue service for advice.

2.0.9 Annexes

2.A - Additional guidance for residential care buildings

2.B - Additional guidance for hospitals

2.C - Additional guidance for enclosed shopping centres

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Certain types of buildings pose particular risks and require particular solutions. Additional guidance for three specific building types are grouped in three annexes; residential care buildings in annex 2.A; hospitals in annex 2.B and enclosed shopping centres in annex 2.C. Where an enclosed shopping centre has a mall on 3 storeys or more, the alternative approach described in clause 2.0.7 should be used.

The intention is to help designers and verifiers find the information they require quickly when designing or vetting such buildings. However it is important to remember that the guidance in the annexes is in addition and supplementary to the guidance to Standard 2.1 to 2.15.

Annex 2.D: Resistance to fire

Resistance to fire is expressed in terms of fire resistance duration and reference throughout this document to a short, medium or long fire resistance duration, are explained in annex 2.D. The performance levels include properties such as loadbearing capacity, integrity and insulation.

Annex 2.E: Reaction to fire

Reaction to fire of construction products is expressed as European Classification A1, A2, B, C, D, E and F (with A1 being the highest performance and F being the lowest). The performance levels include properties such as ease of ignition and rate at which the product gives off heat when burning. Further explanation is provided in annex 2.E including sub-indices for smoke production and/or flaming droplets/particles.

Annex 2.F: Vulnerability of roof coverings

Roof coverings are expressed in terms of low, medium or high vulnerability and explained in annex 2.F. The performance levels relate to the capability of a roof to resist penetration from fire and flame spread when the external surface is exposed to radiation and flames.

2.0.10 Independent third party certification and accreditation

Independent third-party certification or accreditation can be used as evidence towards demonstrating compliance with building regulations. Certification provides third- party confirmation via audit of an organisations systems or products. Accreditation is independent third-party recognition that an organisation has the competence and impartiality to perform specific technical activities such as certification, testing and inspection.

Third party certification of installers of systems, materials, products or structures provides a means of ensuring that installations have been conducted by knowledgeable contractors to appropriate standards, thereby increasing the reliability of the anticipated performance in fire.

Confidence that the required level of performance can be achieved will be demonstrated by the use of product and installer certification schemes that are accredited.

Such certification schemes not only provide a means of identifying materials and designs of systems, products or structures which have demonstrated that they have the requisite performance in fire, but additionally provide confidence that the systems, materials, products or structures actually supplied are provided to the same specification or design as that tested and assessed.

The ‘Guide to Undertaking Technical Assessments of Fire Performance of Construction Products Based on Fire Test Evidence’ (Passive Fire Protection Forum, 2021) provides

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advice including the competency of those undertaking technical assessments linked to levels of complexity. The guidance promotes effective fire safety design to ensure the reliability and quality of passive fire protection materials and systems. The guide also encourages third party certification schemes for the manufacture, installation, inspection and maintenance of products and systems, and relates to the provision of technical assessments that can extend the scope of design and application of a passive product or system by providing a robust and competent approach to technical assessments.

Scottish Ministers can, under Section 7 of the Building (Scotland) Act 2003, approve schemes for the certification of design or construction for compliance with the mandatory functional standards. Such schemes are approved on the basis that the procedures adopted by the scheme will take account of the need to co-ordinate the work of various designers and specialist contractors. Individuals approved to provide certification services under the scheme are assessed to ensure that they have the qualifications, skills and experience required to certify compliance for the work covered by the scope of the scheme. Checking procedures adopted by Approved Certifiers will deliver design or installation reliability in accordance with legislation.

2.1 Compartmentation

Mandatory Standard

Standard 2.1

Every building must be designed and constructed in such a way that in the event of an outbreak of fire within the building, fire and smoke are inhibited from spreading beyond the compartment of origin until any occupants have had the time to leave that compartment and any fire containment measures have been initiated.

Limitation:

This standard does not apply to domestic buildings.

2.1.0 Introduction

The aim of compartmentation is to inhibit rapid fire spread within the building by reducing the fuel available in the initial stages of a fire. The intention is to limit the severity of the fire which in turn should help the occupants to evacuate the building and assist fire and rescue service personnel with fire-fighting and rescue operations. This is achieved by dividing the building into a series of fire tight boxes termed compartments which will form a barrier to the products of combustion; smoke, heat and toxic gases.

The use of a building, the height of the topmost storey, the inclusion of automatic fire suppression systems and the fire resistance duration will determine the maximum area of the compartments within a building. Designers may also choose to construct compartments based on client and aesthetic needs. For example, the designer may use compartmentation to classify the building into different uses or to reduce travel distances (see clause 2.9.3).

Common guidance - the guidance in clauses 2.1.14 (Openings and service penetrations), 2.1.15 (Junctions) and 2.1.16 (Fire resisting ceilings) is common, not only to compartmentation and sub-compartmentation, but also to the relevant guidance in

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Standards 2.2 separation, 2.4 cavities, 2.9 escape and the relevant guidance contained in the annexes.

Due to the special fire precautions within residential care buildings, hospitals and enclosed shopping centres, additional guidance is grouped in the annexes. The intention is to help designers and verifiers find the information they require quickly when designing or vetting such buildings. However it is important to remember that the guidance in the annexes is in addition and supplementary to the guidance to Standards 2.1 to 2.15. For additional guidance on:

•residential care buildings, see annex 2.A

•hospitals, see annex 2.B

•enclosed shopping centres, see annex 2.C.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirement of this standard (regulation 12, schedule 6).

2.1.1 Maximum compartment areas

A building, or part of a building, with a total storey area more than the limits given in the tables below should be sub-divided by compartment walls and, where appropriate, compartment floors. The minimum fire resistance duration (see annex 2.D) can be obtained from the tables below (see also clause 2.1.4).

In most cases, a single-storey building poses less of a life risk to the occupants or to fire and rescue service personnel than a multi-storey building, therefore a greater compartment size can be constructed.

Table 2.1 Single-storey buildings and compartmentation between single-storey and multi- storey buildings where appropriate

Additional information:

1.Areas may be doubled where there is an automatic fire suppression system (see clause 2.1.2).

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2.Unlimited provided there is an automatic fire suppression system (see clause 2.1.2).

3.A medium fire resistance duration compartment wall or compartment floor may be provided between the single-storey part and the multi-storey part provided the multi- storey part does not exceed the limitations for medium fire resistance duration in the following table covering multi-storey buildings (see also clause 2.1.4).

Table 2.2 Multi-storey buildings

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Additional information:

1.Areas may be doubled where there is an automatic fire suppression system (see clause 2.1.2).

2.Medium fire resistance duration for compartment walls.

3.Unlimited provided there is an automatic fire suppression system (see clause 2.1.2).

4.See buildings with different uses (clause 2.1.4).

2.1.2 Automatic fire suppression

Where it is intended to install automatic fire suppression systems, guidance can be obtained in the following publications:

•LPC Rules for Automatic Sprinkler Installations 2009, Incorporating BS EN 12845

•BS 5306: Part 4: 2001 + A1: 2012 for carbon dioxide systems

•BS EN 13565-2: 2018 for low expansion foam systems

•BS EN 12416-2: 2001 for powder systems.

2.1.3 Smoke and heat exhaust ventilation systems

Enclosed shopping centres - a smoke and heat exhaust ventilation system (SHEVS) should be installed in the mall of an enclosed shopping centre and in shops with a storey area more than 1,300m² to prevent cool smoke from entering the mall. Guidance on SHEVS is provided in clause 2.C.1 of annex 2.C.

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Similarly, large shops (other than in enclosed shopping centres), with a compartment area more than 5,600m² should also be provided with SHEVS. Whilst annex 2.C relates to enclosed shopping centres, the guidance in clause 2.C.1 of annex 2.C may also be used for large shops.

2.1.4 Buildings with different uses

Buildings with different uses should be divided by compartment walls and compartment floors. However compartmentation need not be provided if the overall building attains the highest of the performance levels described in the guidance to Standards 2.1, 2.3 and

2.6.The intention is to allow design flexibility without reducing the risk to life safety. This is done by removing the need for compartmentation in a building or parts of a building where the overall building follows the more demanding guidance. For example, a compartment wall between a production area in a factory and part of the building used for storage need not be provided where an assessment of the overall building has been carried out for both uses and:

•the limits for compartmentation have not been exceeded (see clause 2.1.1), and

•the most demanding fire resistance duration of the element of structure has been followed (see clause 2.3.1), and

•the most severe minimum distance to the relevant boundary has been followed (see guidance to Standard 2.6).

However certain buildings are considered to present a lower level of risk to life safety and as a result, are given special consideration even where compartmentation between different uses is necessary. The buildings referred to are offices, shops, Factory (Class

2)or storage building (Class 2). Where the affected parts of the building are in the same occupation (see clause 2.2.2), short fire resistance duration is sufficient in lieu of medium fire resistance duration provided an automatic fire suppression system (see clause 2.1.2) is installed on both sides of the compartment wall, or on the storeys above and below the compartment floor where appropriate.

2.1.5 Residential buildings

In a residential building, every upper storey and every basement storey should form a separate compartment.

2.1.6 High rise buildings

Every floor at a storey height of more than 18m above the ground should be a compartment floor.

2.1.7 Basements

Where a building has a basement storey, the floor of the ground storey should be a compartment floor. However where the building comprises one basement storey and not more than 2 other storeys, and no storey has an area more than 280m², a compartment floor need not be provided.

Where a building has a basement storey at a depth of more than 10m, every basement storey should form a separate compartment.

2.1.8 Places of special fire risk

Paint spraying - a place of special fire risk should be enclosed by compartment walls with a medium fire resistance duration. However this does not apply to a paint spray booth or to a room where cellulose or other flammable liquid spray is used, having a floor area not

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more than 100m², constructed of prefabricated factory-made panels and is constructed in accordance with the recommendations in the Health and Safety Executive Guidance Note PM25 ‘Vehicle finishing units fire and explosion hazards’.

Where a place of special fire risk contains any appliance or equipment using hazardous liquid, any opening in a wall or floor dividing it from the remainder of the building should be constructed in such a manner that, in the event of any liquid spillage, the room will contain all the liquid in the appliance or equipment, plus 10%. See section 3, Environment for guidance on catch pits (bunds) for the storage of oil within a building.

2.1.9 Fire-fighting shafts

A fire-fighting shaft is an enclosure protected from fire in adjoining accommodation and contains an escape stair, a fire-fighting lobby at every storey at which the fire-fighting stair can be entered from the accommodation. The stair may also contain a fire-fighting lift together with its machine room (see clause 2.14.4).

These shafts are used in high buildings, deep buildings and in certain shops or storage buildings to assist fire and rescue service personnel to carry out fire-fighting and rescue operations.

The enclosing structure of a fire-fighting shaft should have a long fire resistance duration. However where the elements of structure in a building have a medium fire resistance duration, then the fire-fighting shaft need only have a medium fire resistance duration. A self-closing fire door in the enclosing structure of a fire-fighting shaft need only attain a medium fire resistance duration (see diagram to clause 2.14.3).

2.1.10 Smoke venting shafts

A smoke venting shaft should be enclosed by compartment walls with a medium fire resistance duration, other than at the smoke inlets and smoke outlets to the shaft.

2.1.11 Lift wells

A lift well should be enclosed by compartment walls with at least medium fire resistance duration and, where the lift well is not the full height of the building, a compartment floor with a medium fire resistance duration (see also capping systems in clause 2.1.15). Where a lift is installed, the landing controls and lift car controls should be of a type that do not operate on heat or pressure resulting from a fire.

A platform lift following the guidance in BS 6440: 1999 (see Section 4, Safety), need not be enclosed by compartment walls or compartment floors.

2.1.12 Combustibility

A compartment wall or compartment floor can be constructed of combustible products provided the appropriate fire resistance duration is maintained (see annex 2.E). However compartment walls and compartment floors in hospitals (see annex 2.B), should be constructed from products which achieve European Classification A1 or A2.

2.1.13 Supporting structure

Where an element of structure provides support to a compartment wall or compartment floor which attracts a higher fire resistance duration, the supporting element of structure should have at least the same period of fire resistance.

2.1.14 Openings and service penetrations

General

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Compartment walls and compartment floors (including a fire resisting ceiling) are intended to prevent fire passing from one compartment to another. Openings and service penetrations through these walls or floors can compromise their effectiveness and should be kept to a minimum. The solum and roof space should not be forgotten. Openings and service penetrations should be carefully detailed and constructed to resist fire. This can be achieved by following the guidance below.

A self-closing fire door with the same fire resistance duration as the compartment wall should be installed in accordance with the recommendations in the Code of Practice, ‘Hardware for Fire and Escape Doors’, published by the Door and Hardware Federation and the Guild of Architectural Ironmongers.

In some instances a self-closing fire door with a reduced fire resistance duration may be installed. For example, a self-closing fire door with a medium fire resistance duration may be installed in the enclosing structure of a fire-fighting shaft with a long fire resistance duration (see clause 2.1.9).

A lockable door to a cupboard or service duct where the cupboard or the service duct have a floor area not more than 3m², need not be self-closing.

Hold open devices - Self-closing fire doors can be fitted with hold open devices as specified in BS 5839: Part 3: 1988 provided the door is not an emergency door, a protected door serving the only escape stair in the building (or the only escape stair serving part of the building) or a protected door serving a fire-fighting shaft.

It is important that hold open devices deactivate on operation of the fire alarm therefore some buildings will need automatic fire detection to be installed. Electrically operated hold open devices should therefore deactivate on operation of:

•an automatic fire alarm system designed and installed in accordance with BS 5839: Part

1:2017 (Category L5) determined on the basis of a risk assessment (see clauses 2.0.8), and

•any loss of power to the hold open device, apparatus or switch, and

•a manually operated switch fitted in a position at the door.

An example of a Category L5 fire alarm system could incorporate only 2 smoke detectors, one installed on each side of the door and positioned at least 500mm and not more than 3m from the door.

As an alternative to the above hold open device, an acoustically activated and/or radio activated door release mechanism and floor plate complying with BS EN 1155: 1997 may be installed on a risk assessment basis (see clause 2.0.8). Additional guidance is contained in BS 7273: Part 4: 2015.

In addition, this type of hold open device is not suitable for use in the following circumstances where:

•the door is an emergency door, or protected door serving the only escape stair in the building (or the only escape stair serving part of the building) or a protected door serving a fire-fighting shaft, or

•a Category M fire alarm system as defined in BS 5839: Part 1: 2017 is installed in the building, or

•the initial fire alarm warning signal is intended to alert staff only.

Additional guidance on the siting and coverage of fire detectors is contained in BS 5839: Part 1: 2017.

Automatically motorised fire shutters - should not be installed in the enclosing structure of a protected zone (see also clauses 2.9.15 and 2.9.27). However they may be used for

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the protection of service openings and ventilation ducts. Automatic motorised fire shutters should be fitted with audible and visual warning devices that operate on fire detection prior to activation of the fire shutter. However this is only necessary where there is a risk of people moving under the shutter in the event of an outbreak of fire within the building.

The visual warning devices should be fitted on both sides of the opening where the movement of people below the shutter is possible from both directions. Sensors should also be fitted that, when activated, temporarily halt the activation of the shutter. Automatic fire shutters should not be activated by a fire alarm signal from a remote location or out- with the fire alarm zone.

Fire shutter in compartment walls - a fire shutter which is not motorised may be fitted in a compartment wall provided the shutter has the same fire resistance duration as the compartment wall (see table to annex 2.D). Since a shutter activated by a fusible link or other heat sensitive device is not considered to be a threat to the occupants, warning devices need not be fitted.

Fire shutter in compartment floors - where an opening in a compartment floor contains a stair (but not an escape stair) and not more than 2 escalators:

•a horizontal fire shutter may be installed which maintains the fire resistance duration of the compartment floor and is activated by a fusible link or other heat-sensitive device positioned to detect fire in the lower compartment, or

•vertical fire shutters may be installed at each floor level (other than the topmost storey) which maintains the fire resistance duration of the compartment floor and are activated by smoke detection positioned to detect smoke in the lower compartment.

Where an escalator passes through the opening, it should come to a controlled halt before the fire shutter is activated.

A chimney or flue-pipe should be constructed so that, in the event of a fire, the fire resistance duration of the compartment wall or compartment floor is maintained.

A service opening (other than a ventilating duct) which penetrates a compartment wall or compartment floor should be fire stopped providing at least the appropriate fire resistance duration for the wall or floor. This may be provided by:

•a casing which has at least the appropriate fire resistance duration from the outside, or

•a casing which has at least half the appropriate fire resistance duration from each side, or

•an automatic heat activated sealing device that will maintain the appropriate fire resistance in respect of integrity for the wall or floor regardless of the opening size.

Fire stopping of the following services passing through a compartment wall or compartment floor need not be provided for:

•a pipe or cable with a bore, or diameter, of not more than 40mm, or

•not more than four 40mm diameter pipes or cables that are at least 40mm apart and at least 100mm from any other pipe, or

•more than four 40mm diameter pipes or cables that are at least 100mm apart, or

•a pipe which has a bore of not more than 160mm and is of iron, steel or copper, or of a material capable of withstanding 800°C without allowing flames or hot material to pass through the wall of the pipe, or

•a pipe which has a bore of not more than 110mm connected to a vertical drainage or water service pipe, constructed from aluminium, aluminium alloy, or uPVC to BS 4514: 2001.

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Where a pipe connects to another pipe which attracts a more demanding fire resistance duration, and is within 1m from the compartment wall or compartment floor, the pipe should be fire stopped to the more demanding guidance.

Ventilation systems - the potential for ventilation systems to allow the spread of fire and smoke should be considered. A mechanical ventilation system may contribute to the spread of fire and smoke unless it is designed to shut down automatically or operate in a fire-mode if fire is detected. Ventilation ductwork passing through a compartment wall or compartment floor or other fire resisting construction protecting escape routes should be provided with either:

•fire dampers, or

•fire resisting enclosures, or

•fire resisting ductwork.

Ventilation ductwork should be designed and installed in accordance with BS 5588: Part

9:1999. Section 6 of BS 5588: Part 9: 1999 (excluding the third paragraph to clause

6.3.3.2.2)provides guidance on design and construction including fire resisting enclosures, fire resisting ductwork and the use and activation of fire dampers.

Fire-stopping may be necessary to close an imperfection of fit or design tolerance between construction elements and components, service openings and ventilation ducts. Proprietary fire-stopping products including intumescent products, should be tested to demonstrate their ability to maintain the appropriate fire resistance duration under the conditions appropriate to their end use.

Where minimal differential movement is anticipated, either in normal use or during fire exposure proprietary fire-stopping products may be used. The following materials are also considered appropriate: cement mortar; gypsum based plaster; cement or gypsum based vermiculite/perlite mixes; mineral fibre; crushed rock and blast furnace slag or ceramic based products (with or without resin binders).

Where greater differential movement is anticipated, either in normal use or during fire exposure, the use of proprietary fire-stopping products may be used.

To prevent displacement, materials used for fire-stopping should be reinforced with, or supported by, products which achieve European Classification A1 or A2 where the unsupported span is more than 100mm and where non-rigid materials are used. However this is not necessary where it has been shown by test that the materials are satisfactory within their field of application.

2.1.15 Junctions

General - The basic principle is that junctions between compartment walls and compartment floors (including fire resisting ceilings, see clause 2.1.16) and other parts of the building should be designed and constructed to minimise the risk of a fire in one compartment flanking the wall, floor or ceiling and entering an other compartment at the junctions including any solum space or roof space (see annex 2.B for additional guidance on hospitals). Therefore, the building elements, materials or components should not be built into, or carried through or across the ends of, or over the top of a compartment in such a way as to impair the fire resistance duration between the relevant parts of the building.

Technical assessments are often required when designing or verifying the fire performance of junction details. The ‘Guide to Undertaking Technical Assessments of Fire Performance of Construction Products Based on Fire Test Evidence’ (Passive Fire Protection Forum, 2021) provides advice including the competency of those undertaking technical assessments linked to levels of complexity. The guidance promotes effective fire safety design to ensure the reliability and quality of passive fire protection materials and systems. The guide also encourages third party certification schemes for the manufacture,

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installation, inspection and maintenance of products and systems, and relates to the provision of technical assessments that can extend the scope of design and application of a passive product or system by providing a robust and competent approach to technical assessments.

Junctions with walls - Where a separating wall or separating floor forms a junction with an external wall, another separating wall, or a wall or screen used to protect routes of escape (see clause 2.0.6), the junction should maintain the fire resistance duration of the separating wall or separating floor.

Where a separating wall or floor or protected route of escape abuts a structure containing a cavity, a fire barrier or barriers should be installed in the cavity so as to extend the line, and maintain the fire resistance duration, of the wall or floor. This principle also applies where an external wall cladding system is constructed from materials having a European Classification A1 or A2 (other than between two leaves of masonry as described below). For example, in a rendered external thermally insulated cladding system where the insulation achieves European Classification B, C, D, E or F, a fire barrier or barriers should be provided on the line of the separating wall or floor. The barrier should extend from the wall/floor to the inner surface of the render (this may require an intumescent barrier within any drainage cavity that may be present).The guidance in this clause does not apply where the external wall is formed by two leaves of masonry or concrete where both leaves are at least 75mm thick and the external wall is provided with cavity barriers around all openings and at the top of the wall-head.

There are merits in testing products in a large scale facade fire test to assess how the individual components perform in a complete assembly when exposed to a severe fire emanating from a window or door opening(see annex 2E).

Junctions with roofs - where a compartment wall forms a junction with a roof, the junction should maintain the fire resistance duration of the compartment wall in accordance with the following:

•where the roof has a combustible substrate, the wall should project through the roof to a distance of at least 375mm above the top surface of the roof, or

•where the wall is taken to the underside of a roof substrate which achieves a European Classification A1 or A2, the junction should be fire stopped and the roof covering should be low vulnerability (see guidance to Standard 2.8) for a distance of at least 1.7m to each side of the centre-line of the wall, or

•in the case of a pitched roof covered by slates nailed directly to sarking and underlay, the junction between the sarking and wall-head should be fire stopped as described in BRE Housing Defects Prevention Unit Defect Action Sheet (Design) February 1985 (DAS 8), or

•in the case of a pitched roof covered by slates or tiles fixed to tiling battens and any counter-battens, the junction between the tiles or slates and the underlay should be fully bedded in cement mortar (or other fire stopping material, see clause 2.1.14) at the wall- head.

Junctions with fire resisting ceilings - where a compartment wall does not extend to the full height of the building, the wall should form a junction with a compartment floor.

Non-full height walls - however this may not always be the most practical solution. At the topmost storey of a building for example it is possible for the compartment wall to form a junction with a fire resisting ceiling (see clause 2.1.16), (including a suspended ceiling) or a localised capping system, provided the fire resistance duration is maintained and the junction between the wall and ceiling is fire stopped.

Capping system - to ensure that occupants will be protected during evacuation and to protect fire and rescue service personnel during fire-fighting and rescue operations, a

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localised capping system could be constructed at the head of a protected zone or a lift shaft. The system should be fire protected on both sides and be sufficiently robust to protect against premature collapse of the roof structure. There is currently no fire test from the top-side of a capping system, the assumption being that if the test satisfies the fire resistance duration from the underside then it will also satisfy the same criteria from the top-side using the same construction.

The junctions between protected routes of escape (see clause 2.0.6) and other parts of the building are particularly vulnerable to fire and smoke. This is because fire and smoke can penetrate weaknesses at junctions, which could compromise the means of escape. The continuity of the fire-stopping should be designed and constructed in order to provide a complete barrier to fire between the relevant parts of the building.

Protected routes of escape - where part of a building is a protected route of escape and forms a junction with any other part of the building including for example, an external wall, a separating wall, another compartment wall or any other wall or screen forming a protected route of escape, the junction should maintain the fire resistance duration of the more demanding guidance.

In order to inhibit the spread of fire and smoke, junctions should be protected in accordance with the above guidance. For additional guidance on fire-stopping materials, see clause 2.1.14.

2.1.16 Fire resisting ceilings

Where a fire resisting ceiling, including a suspended ceiling, contributes to the fire resistance duration of a compartment floor or is part of a construction as described in clause 2.1.15, the ceiling should be constructed in accordance with the following recommendations:

•the ceiling should not be easily demountable

•openings and service penetrations in the ceiling should be protected in accordance with clause 2.1.14

•junctions with the ceiling should follow the guidance in clause 2.1.15

•the ceiling lining should follow the guidance to Standard 2.5

•the ceiling may contain an access hatch which, when closed, will maintain the fire resistance duration of the ceiling.

However the guidance in this clause should not be applied to fire resisting ceilings protecting the load-bearing capacity of a floor only. In such cases, the compartment wall should be taken through the ceiling and floor to form a continuous and complete barrier to fire between the relevant compartments.

2.2 Separation

Mandatory Standard

Standard 2.2

Every building, which is divided into more than one area of different occupation, must be designed and constructed in such a way that in the event of an outbreak of fire within the building, fire and smoke are inhibited from spreading beyond the area of occupation where the fire originated.

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Buildings or parts of a building in different occupation pose particular problems in terms of fire safety. This is because one occupier usually does not have any control over the activities or working practices of their co-occupiers and in such cases, separating walls and separating floors are recommended.

The intention of separation is to limit fire growth and thereby give adjoining occupiers more time to escape before they are threatened by fire or smoke.

Enclosed shopping centres - due to the special fire precautions within enclosed shopping centres, additional guidance is grouped in the annex 2.C. The intention is to help designers and verifiers find the information they require quickly when designing or vetting such buildings. However it is important to remember that the guidance in the annexes is in addition and supplementary to the guidance to Standards 2.1 to 2.15.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirements of this standard in so far as is reasonably practicable, and in no case be worse than before the conversion (regulation 12, schedule 6).

2.2.1 Separating walls and separating floors

Separating walls and separating floors should have at least a medium fire resistance duration (see annex 2.D). However there are some situations where the wall or floor will demand a greater fire resistance duration. For example, where the separating floor is also an element of structure in a building where the topmost storey is at a height of more than 18m, long fire resistance duration would be necessary in most cases (see clause 2.1.1).

2.2.2 Buildings in different occupation

A separating wall or separating floor should be provided between parts of a building where they are in different occupation.

Multi-occupied building - however it is possible to have no separating walls or separating floors between the different occupiers of a multi-occupied building when the building is under a single management regime. For example, multi-occupied offices with a shared reception and sanitary facilities may be regarded as being in the same occupation. In such cases, the building should have a common fire alarm system/evacuation strategy and the same occupancy profile (see clause 2.9.3). This philosophy is in effect very similar to individual departments within one large organisation. However where each unit is under the control of an individual tenant, employer or self-employed person, separating walls and separating floors should be provided between the areas intended for different occupation.

Where a speculative development is intended to be multi-occupied but the extent of management control is not known, the building should be regarded as being occupied by different persons.

2.2.3 Building with common occupation

A separating wall or separating floor with a medium fire resistance duration should be provided between parts of a building where one part is in single occupation and the other is in communal occupation. However this is not necessary between:

•part of a building in single occupation and a common external stair, access balcony or access deck

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•a shop and a mall (see annex 2.C).

2.2.4 Combustibility

Every part of a separating wall or separating floor (other than a floor finish such as laminate flooring) should be of products that which achieve European Classification A1 or A2. However this is not necessary where the building does not have any storey at a height of more than 18m and the separation is between:

•a shop or office and a dwelling above the shop or office in the same occupation where there is no other dwelling above the shop or office, and the area of the shop or office is not more than 1½ times the area of the separating floor, or

•units of shared residential accommodation, or

•a dwelling and a unit of shared residential accommodation.

To reduce the risk of a fire starting within a combustible separating wall or a fire spreading rapidly on or within the wall construction:

•insulation exposed in a cavity should be constructed from products which achieve European Classification A1, A2 or B (see annex 2.E), and

•the internal wall lining should be constructed from products which achieve European Classification A1, A2, or B, and

•the wall should contain no pipes, wires or other services.

2.2.5 Supporting structure

Where an element of structure (see clause 2.3.0) provides support to a separating wall or separating floor, constructed from products which achieve European Classification A1 or A2, the supporting element of structure should also achieve European Classification A1 or A2.

Where an element of structure provides support to a separating wall or separating floor which attracts a higher period of fire resistance duration, the supporting element of structure should have at least the same period of fire resistance duration.

2.2.6 Openings and service penetrations

Guidance on the fire protection of openings and service penetrations is provided in clause 2.1.14. However self-closing fire doors should not be installed in separating walls other than in the situation described in clause 2.2.3 or where the building is in the same occupation but in different use. A fire shutter should not be installed in a separating wall or separating floor.

2.2.7 Junctions

Where a separating wall or separating floor meets an external wall, another separating wall, a compartment wall or any other wall or screen used to protect routes of escape (see clause 2.0.6), the junction should maintain the fire resistance duration of the separating wall or separating floor (see clause 2.1.15). Where a separating wall forms a junction with a roof or a fire resisting ceiling (see clause 2.1.16), the junction should be constructed in accordance with the recommendations in clause 2.1.15.

Where a separating wall or floor abuts a structure containing a cavity, a fire barrier should be installed in the cavity so as to extend the line, and maintain the fire resistance duration,

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of the wall or floor. However this is not necessary where the cavity is formed by two leaves of masonry or concrete where both leaves are at least 75mm thick and the external wall is provided with cavity barriers around all openings and at the top of the wall-head.

2.3 Structural protection

Mandatory Standard

Standard 2.3

Every building must be designed and constructed in such a way that in the event of an outbreak of fire within the building, the load-bearing capacity of the building will continue to function until all occupants have escaped, or been assisted to escape, from the building and any fire containment measures have been initiated.

2.3.0 Introduction

In order to prevent the premature collapse of the load-bearing structural elements of a building, appropriate levels of fire resistance duration (see annex 2.D) should be provided to all element of structure. The purpose of structural fire protection is:

•to minimise the risk to the occupants, some of whom may not evacuate the building immediately, and

•to reduce the risk to fire-fighters who may be engaged in fire-fighting or rescue operations.

An element of structure may perform more than one function and it is important that the appropriate guidance related to the different standards is followed.

The added benefit to structural fire protection means that the risk to people in the vicinity of the building or in adjoining buildings from collapse of the structure is reduced.

An element of structure is part of a building which is part of a structural frame (beams and columns), load-bearing (other than part which is only self-load bearing), a floor, or supports a floor. An example of part of the structure that is only self load-bearing could be a lintel in a non load-bearing wall. A roof structure should not be considered as an element of structure unless the roof provides support to an element of structure or which performs the function of a floor.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirement of this standard (regulation 12, schedule 6).

2.3.1 Elements of structure

It is essential that during a fire the elements of structure should continue to function. They should remain capable of supporting and retaining the fire protection to floors, escape routes and fire access routes, until all occupants have escaped, or assisted to escape or been rescued by the fire and rescue service. In practice, the fire and rescue service could remain in the building long after it has been evacuated. For this reason, an additional level of protection is built into the guidance for non- domestic buildings that varies depending on the height of the topmost storey of the building.

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The element of structure in a building should have at least the fire resistance duration as set out in the tables to clause 2.1.1.

However the following elements of structure need not be provided with any fire resistance duration for structural protection:

•an elements of structure in a single-storey building which does not form part of, or provide support to, a separating wall, compartment wall, a sub-compartment wall in a residential care building or hospital, a wall or screen used to protect routes of escape (see clause 2.0.6) or an external wall which attracts a fire resistance duration (as in the guidance to Standard 2.6)

•a floor consisting of removable panels situated directly above a floor which is an element of structure

•a gallery floor other than a gallery floor which is wholly or partly enclosed below (see clause 2.9.17)

•an openwork floor

•a catwalk (including a lighting bridge), or

•the lowest floor of a building.

2.3.2 Combustibility

An element of structure may be constructed from combustible material provided the construction achieves the appropriate fire resistance duration.

However, where an element of structure provides support to another element of structure (or a protected route of escape, see clause 2.0.6) which should be constructed from products that achieve European Classification A1 or A2, the supporting element of structure should also be constructed from products that achieve European Classification A1 or A2 (see annex 2.E).

2.3.3 Supporting structure

Where an element of structure provides support to another element of structure (or provides support to a protected route of escape) which attracts a higher period of fire resistance duration, the supporting element of structure should have at least the same period of fire resistance duration.

2.3.4 Openings and service penetrations

In general, openings and service penetrations in elements of structure need not be protected from fire unless there is the possibility of structural failure. However where a large opening or a large number of small openings are formed, careful detailing particularly at the edge of the opening or service penetration should be carried out in order to maintain the load-bearing capacity of the element of structure. If in doubt, edge protection should be provided.

2.3.5 Junctions

The detailing of junctions between relevant parts of a building is described in clauses 2.1.15, 2.1.16, 2.2.7, 2.4.9 and 2.9.28. Fire-stopping of other junctions is generally not necessary. The important criteria to consider is the ability of the element of structure to

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maintain its load-bearing capacity in a fire in accordance with the fire resistance duration set out in the tables to clause 2.1.1 (see also annex 2.D).

2.4 Cavities

Mandatory Standard

Standard 2.4

Every building must be designed and constructed in such a way that in the event of an outbreak of fire within the building, the spread of fire and smoke within cavities in its structure and fabric is inhibited.

2.4.0 Introduction

Fire and smoke spread in cavities is particularly hazardous because fire can spread quickly throughout a building and remain undetected by the occupants of the building or by fire and rescue service personnel. Ventilated cavities generally promote more rapid fire spread around the building than unventilated cavities due to the plentiful supply of air. Buildings containing sleeping accommodation pose an even greater risk to life safety and demand a higher level of fire precautions. For these reasons, it is important to control the size of cavities and the surfaces exposed in the cavity.

Large air plenums present difficulties due to the very nature of their design and an alternative approach (see clause 2.0.7) may be the only viable alternative.

The guidance for protection to cavities should not be assessed in isolation and reference should be made to the guidance to Standard 2.1 for compartmentation, Standard 2.2 for separation, Standard 2.6 for spread to neighbouring buildings and the guidance to Standard 2.7 for fire spread on external walls.

A cavity is a concealed space enclosed by elements of a building (including, for example, the void above a suspended ceiling) or contained within a building element, but not a room, cupboard, circulation space, stair enclosure, lift well, chimney or a space within a chute, duct, pipe or conduit. For the purposes of this guidance, a cavity includes a roof space, a service riser or any other space used to run services around the building.

Reference to surfaces in a cavity is intended to include the surface of the enclosing envelope of the cavity (including insulation material) but excludes timber roof trusses or lintols, joist ends, pipes, conduits or cables.

Due to the special fire precautions within residential care buildings and hospitals, additional guidance is grouped in the annexes. The intention is to help designers and verifiers find the information they require quickly when designing or vetting such buildings. However it is important to remember that the guidance in the annexes is in addition and supplementary to the guidance to Standard 2.1 to 2.15. For additional guidance on:

•residential care buildings, see annex 2.A

•hospitals, see annex 2.B.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirements of this standard in so far as is reasonably practicable, and in no case be worse than before the conversion (regulation 12, schedule 6).

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A cavity barrier means any construction provided to seal a cavity against the penetration of fire and smoke or to restrict its movement within the cavity.

In order to inhibit fire spread in a cavity, every cavity within a building should have cavity barriers with at least a short fire resistance duration (see annex 2.D) installed around the edges of the cavity. This includes for example, around the head, jambs and cill of an external door or window opening. A cavity barrier should also be installed between a cavity and any other cavity or between a roof space and any other roof space.

However cavity barriers are not necessary at a junction between 2 cavity walls each comprising two leaves of masonry or concrete where both leaves are at least 75mm thick.

Sealing cavities can sometimes create difficulties, especially where construction techniques rely on through ventilation of the cavity (see Section 3 Environment) or where the detailing should take into account the effect of thermal bridging (see Section 6 Energy).

In an external wall, open state intumescent cavity barriers may be used to inhibit fire and smoke spread and seal the cavity. It is recognised that smoke will spread beyond the cavity barrier at the incipient and early fire growth phases prior to the intumescent material reacting to heat but this is not considered to be a major concern as the cavity is ventilated to atmosphere.

Cavity barriers and ceilings provided as an alternative to cavity barriers generally do not need to be constructed of products that achieve European Classification A1 or A2 unless they perform more than one function such as a cavity barrier that is also a separating wall constructed from products which achieve European Classification A1 or A2.

2.4.2 Dividing up cavities

Cavities should be measured either horizontally or vertically, as the case maybe, along the centre-line of the cavity and not diagonally.

Every cavity should be divided by cavity barriers so that the maximum distance between cavity barriers is not more than 20m where the cavity has exposed surfaces which achieve European Classification A1, A2 or B, or 10m where the cavity has exposed surfaces which achieve European Classification C, D, E or F. However for roof space cavities above an undivided space the guidance in clause 2.4.3 should be followed. Additional guidance for buildings containing a sleeping risk (other than residential care buildings and hospitals) is also provided in clause 2.4.4.

Exclusions - cavity barriers are not necessary to divide a cavity:

a.formed by two leaves of masonry or concrete where both leaves are at least 75mm thick, or

b.in a ceiling void between a floor and a ceiling constructed in accordance with the guidance in clause 2.4.5, or

c.between a roof and a ceiling constructed in accordance with the guidance in clause 2.4.5, or

d.below a floor next to the ground where the cavity is either inaccessible or is not more than 1m high, or

e.between a floor which is an element of structure (see clause 2.3.0), and a raised floor consisting of removable panels.

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The need to provide cavity barriers in a roof space above undivided (or open plan) spaces is less important than that in clause 2.4.2. This is because roof spaces are regarded as having a low fire risk and the occupants in an undivided (or open plan) space should be aware of any fire developing. In such cases, the occupants should be able to make their escape in the early stages of the fire growth. However where there is sleeping accommodation, the material exposed in the cavity and the size of a cavity, should be controlled due to the nature of the risk. In such cases the limits set in the table below should not be exceeded.

It is also possible to install cavity barriers in roof spaces constructed in accordance with a combination of the guidance for divided and undivided spaces. For example, rooms adjoining a large open plan room can be separated from the open plan room by installing cavity barriers in the roof space between the two spaces. This will allow the 2 roof spaces to be assessed independently.

Table 2.3 Recommended distance between cavity barriers in roof spaces above undivided spaces (m)

A ceiling constructed in accordance with the guidance in clause 2.4.5 may be provided as an alternative to installing cavity barriers.

Note

Limit of 20m should be applied in residential care buildings and hospitals.

2.4.4 Cavities above ceilings in residential buildings (other than residential care buildings and hospitals)

Divided spaces with a sleeping risk - where a roof space cavity or a ceiling void cavity extends over a room intended for sleeping, or over such a room and any other part of the building, cavity barriers should be installed on the same plane as the wall. The intention is to contain the fire within the room of fire origin allowing occupants in other parts of the building to make their escape once the fire alarm has activated (see guidance to Standard 2.11). However in cases where this is not the most practical solution, a fire resisting ceiling can be installed as an alternative to cavity barriers (see clause 2.4.5).

The risk of fire spread above ceilings in residential care buildings and hospitals is covered by the additional guidance for sub-compartmentation in annex 2.A and annex 2.B.

2.4.5 Fire resisting ceilings as an alternative to cavity barriers

Where a fire resisting ceiling is provided as an alternative to cavity barriers as in clauses 2.4.2b, 2.4.2c, 2.4.3 and 2.4.4, the ceiling should have at least short fire resistance duration and be constructed in accordance with the guidance in clause 2.1.16.

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Fire-fighters may not be able to apply a water jet from a fire-fighting hose directly onto a fire that has spread within an external wall or onto an external wall. This is because the external wall is either inaccessible or is too high above the ground to be within the reach capability of fire-fighting equipment such as hydraulic platforms or turntable ladders, therefore, the construction of external walls should not contribute to the development of fire or contribute to fire spread within cavities or vertical fire spread up the facade of the building. Fire-fighters may require to cut holes in the external envelope of a building in order to gain access to the cavity to extinguish or control fire spread in the cavity. This can be particularly challenging when the cavity is ventilated and the surfaces exposed in the cavity promote rapid fire spread.

Relevant buildings – with a storey height of 11m or more above the ground, thermal insulation material situated or exposed within a cavity an external wall cavity, or in a cavity formed by an external wall cladding system, must be constructed of products which achieve European Classification A1 or A2 (see annex 2.E).

Buildings (other than relevant buildings) – with a storey height of 11m or more, thermal insulation material situated or exposed within an external wall cavity or a cavity formed by an external wall cladding system, should be constructed of products which achieve European Classification A1 or A2 (see annex 2.E). Alternatively, the approach as described in annex 2.E may be used.

The guidance in this clause does not apply to insulation in a cavity that is between two leaves of masonry or concrete where both leaves are at least 75mm thick, and which has a cavity barrier around all openings in the wall and at the top of the wall-head.

2.4.7 Supporting structure

A cavity barrier should be fixed so that its performance is not affected by:

•movement of the building due to subsidence, shrinkage or thermal collapse in a fire of any services penetrating it

•failure in a fire of its fixings

•failure in a fire of any material or element of structure which it abuts.

However, where a cavity barrier is installed in a roof space, there is no need to protect roof members that support the cavity barrier.

2.4.8 Openings and service penetrations

A cavity barrier and a ceiling provided as an alternative to a cavity barrier may contain a self-closing fire door (or a hatch in the case of a ceiling), or a service opening constructed in accordance with the guidance in clause 2.1.14.

2.4.9 Junctions

All cavity barriers should be tightly fitted to rigid construction. Where this is not possible as in the case of a junction with tiles, corrugated sheeting or other forms of construction containing a cavity, the fire performance of the junction should be maintained. The Standard 2.1 and 2.2 including fire barriers and fire-stopping may be used to satisfy Standard 2.4.

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Mandatory Standard

Standard 2.5

Every building must be designed and constructed in such a way that in the event of an outbreak of fire within the building, the development of fire and smoke from the surfaces of walls and ceilings within the area of origin is inhibited.

2.5.0 Introduction

The building contents are likely to be the first items ignited in a fire and are beyond the scope of this guidance. Materials used in walls and ceilings can however significantly affect the spread of fire and its rate of growth. Fire spread on internal linings in escape routes is particularly important because rapid fire spread in protected zones and unprotected zones could prevent the occupants from escaping.

The use of highly combustible metal composite material panels referred to and defined in Regulation 8 of the Building (Scotland) Amendment Regulations 2022 is prohibited.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirement of this standard (regulation 12, schedule 6).

2.5.1 Internal linings

Wall and ceiling surfaces mean the substrate or lining material including any treatment thereof to restrict flame spread, but excludes any decorative wallpaper or paints. Whilst it is accepted that such wallpaper or paints are not controlled by the guidance, multiple layers applied to the face of a wall or ceiling surface can increase flame spread and hence the fire growth rate. For this reason, multiple layers are not recommended when carrying out refurbishment work involving the re-decoration of wall and ceiling surfaces.

Every room, fire-fighting shaft, protected zone or unprotected zone, should have at least wall and ceiling surfaces with a reaction to fire which follows the guidance in the table below:

Table 2.4 European Classification for reaction to fire of wall and ceiling surfaces (see annex 2.E)

Additional information:

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1.Including any toilet or washroom within a protected zone.

2.At least European Classification D in a room not greater than 4m².

3.Ceilings may be at least European Classification C.

4.At least European Classification B in storage building (Class 1).

5.In an enclosed shopping centre, structural timbers supporting glazing that forms part of a shop front, unit signs and stallboard risers can be constructed of products which achieve European Classification B, C or D provided they are not more than 20% in total, of the area of the shop front.

Limitations on higher risk surfaces - in a room, any part of the wall may be of one reaction to fire classification lower than that recommended in the table above, where the total area of those parts in any one room is not more than half the floor area of the room. This is subject to a maximum of 20m² in residential buildings and 60m² in non-residential buildings.

In a building solely housing livestock, the surfaces of unprotected zones may have any classification of reaction to fire.

2.5.2 Assessment of linings

Wall and ceiling linings should be assessed for their reaction to fire characteristics.

Wall linings - the following wall surfaces should be included in the assessment:

•glazing except glazing in doors, and

•any part of a ceiling which slopes at an angle of more than 70º to the horizontal.

However the following surfaces need not be taken into account:

•doors and door frames

•window frames and frames in which glazing is fitted

•skirtings and facings, cover moulds, picture rails and similar narrow members, and

•fireplace surrounds, mantle shelves and fitted furniture.

Ceiling linings - the following ceiling surfaces should be included in the assessment:

•the surface of glazing

•any part of a ceiling which slopes at an angle of 70º or less to the horizontal.

However the following need not be taken into account:

•ceiling hatches and their frames

•the frames of windows or rooflights and the frames in which glazing is fitted

•facings, cover moulds, picture rails and similar narrow members.

2.5.3 Plastic glazing

External windows and internal glazing to rooms (but not to protected zone or unprotected zones) may be fitted with plastic glazing materials which are:

•rigid solid PVC (uPVC), or

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•polycarbonate rigid solid sheet at least 3mm thick, or

•multiskin polycarbonate sheet at least 10mm thick overall which achieves European Classification B or C.

2.5.4 Thermoplastic material

Thermoplastic materials in ceilings, rooflights and lighting diffusers provide a significant hazard in a fire. Burning droplets can rapidly increase the fire growth rate and the smoke produced is normally dense and toxic which combine to produce extremely hazardous conditions. For these reasons, thermoplastic material should not be used in protected zones or fire-fighting shafts. However thermoplastic materials may still be used with limited application for some ceilings (see clause 2.5.5), rooflights (see clause 2.5.6) or light fittings with diffusers (see clause 2.5.7).

A thermoplastic material means any synthetic material that has a softening point below 200ºC when tested in accordance with BS EN ISO 306: 2004 Method A120 Plastics - Thermoplastic Materials - Determination of Vicat softening temperature.

Rigid Thermal Plastic TP(a) rigid means:

•rigid solid (solid as distinct from double or multiple-skin) polycarbonate sheet at least 3mm thick, or

•multi-skinned rigid sheet made from unplasticised pvc or polycarbonate which has European Classification B or C for reaction to fire, or

•any other rigid thermoplastic product, a specimen of which (at the thickness of the product as put on the market), when tested in accordance with Method 508A in BS 2782: 2004 performs so that the test flame extinguishes before the first mark, and the duration of flaming or afterglow does not exceed 5 seconds following removal of the burner.

Flexible Thermoplastic TP(a) flexible means:

•flexible products not more than 1mm thick which satisfy the Type C provisions of BS 5867: Part 2: 1980 (1993) when tested in accordance with Test 2 in BS 5438: 1989 (1995) with the flame applied to the surface of the specimens for 5, 15, 20 and 30 seconds respectively, but excluding cleansing procedure.

Semi-rigid Thermoplastic TP(b) semi-rigid means:

•a rigid solid polycarbonate sheet product not more than 3mm thick, or multiple-skin polycarbonate sheet products which do not qualify as TP(a) by test, or

•other products which, when a specimen of the material more than 1.5mm and not more than 3mm thick is tested in accordance with Method 508A in BS 2782: 2004, has a rate of burning which is not more than 50mm/minute.

2.5.5 Thermoplastic materials in ceilings

A ceiling constructed from thermoplastic materials, either as a suspended or stretched skin membrane with a TP(a) flexible classification should be supported on all sides and each panel should not exceed 5m² per panel. However this does not apply to a ceiling which has been satisfactorily tested as part of a fire resisting ceiling system. A ceiling with a TP(a) flexible classification should not be installed in the ceiling of a protected zone or fire-fighting shaft.

Subject to clauses 2.5.6 and 2.5.7, the use of thermoplastic materials with a TP(a) rigid or TP(b) semi-rigid classification is unlimited.

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Thermoplastic materials (other than TP(a) flexible) may be used in rooflights subject to the recommendations in the table and diagram below.

Thermoplastic rooflights should also be constructed in accordance with the guidance to Standard 2.8.

2.5.7 Thermoplastic materials in light fittings with diffusers

Thermoplastic materials may be used in light fittings with diffusers. Where the lighting diffuser forms an integral part of the ceiling, the size and disposition of the lighting diffusers should be in accordance with the table and diagram below.

However where the lighting diffuser forms an integral part of a fire resisting ceiling system which has been satisfactorily tested, the amount of thermoplastic material is unlimited.

Where light fittings with thermoplastic diffusers do not form an integral part of the ceiling, the amount of thermoplastic material is unlimited provided the lighting diffuser is designed to fall out of its mounting when softened by heat.

Table 2.5 Thermoplastic rooflights and light fittings with diffusers

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rooflights (m) figure 2.2)

Additional information:

1.Smaller panels can be grouped together provided that the overall size of the group and the space between any others, satisfies the dimensions shown in figure 2.1 below.

2.The minimum 3m separation in the diagram below should be maintained between each 5m² panel. In some cases therefore, it may not be possible to use the maximum percentage quoted.

3.TP(a) flexible is not recommended in rooflights.

Figure 2.1 Layout restrictions on thermoplastic rooflights and light fittings with diffusers

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Figure 2.2 Layout restrictions on small TP(b) rooflights and light fittings with diffusers

Additional information

1.X = Maximum dimension of the largest diffuser or rooflight above.

2.Y = Maximum dimension of the smallest diffuser or rooflight above.

2.5.8 Sandwich panels

A sandwich panel is a factory-made, non load-bearing component of a wall, ceiling or roof consisting of a panel having an insulated core filling the entire area between sheet metal outer facings, which may or may not have decorative and/or weatherproof coatings.

A sandwich panel used for internal walls or linings in a residential building should achieve European Classification A1 or A2.

A sandwich panel used for internal walls or linings in a non-residential building should be designed and installed in accordance with the ‘Design, Construction, Specification and Fire Management of Insulated Envelopes for Temperature Controlled Environments’, International Association of Cold Storage Contractors (European Division), 2008.

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Mandatory Standard

Standard 2.6

Every building must be designed and constructed in such a way that in the event of an outbreak of fire within the building, the spread of fire to neighbouring buildings is inhibited.

2.6.0 Introduction

In order to reduce the danger to the occupants of other buildings, one building should be isolated from another by either construction or distance. The distance between a building and its relevant boundary is dictated by the amount of heat that is likely to be generated in the event of fire. Generally, this will be influenced by how the building is used, compartmented (see guidance to Standard 2.1), separated (see guidance to Standard

2.2)and the extent of any openings or other unprotected areas in the external wall of the building.

The guidance for fire spread to neighbouring buildings should not be assessed in isolation and reference should be made to the guidance to Standard 2.4 for fire spread in cavities and the guidance to Standard 2.7 for fire spread on external walls.

The use of highly combustible metal composite material panels referred to and defined in Regulation 8 of the Building (Scotland) Amendment Regulations 2022 is prohibited.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirements of this standard in so far as is reasonably practicable, and in no case be worse than before the conversion (regulation 12, schedule 6).

2.6.1 Fire resistance duration of external walls

External walls should have at least the fire resistance duration as shown in the table below, apart from the amount of unprotected area set out in clause 2.6.2. For guidance on automatic fire suppression systems, see clause 2.1.2.

The installation of an automatic fire suppression system greatly reduces the amount of radiant heat flux from a fire through an unprotected opening and this is recognised in the table to clause 2.6.1 and in the guidance to clause 2.6.2.

Table 2.6 Recommended fire resistance duration of external walls (see annex 2.D)

Use of building Not more than 1m from More than 1m from the the boundary boundary No fire Fire No fire Fire suppression suppressionsuppression suppression system system system system

Assembly building Medium Medium Medium [1, 2c] None [2c]

Entertainment building Medium Medium Medium [2b] Medium [1] [2b]

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Use of building Not more than 1m from More than 1m from the the boundary boundary No fire Fire No fire Fire suppression suppressionsuppression suppression system system system system

Factory and Storage Medium Medium Medium [3] Medium [1, 4] building Residential building Medium Medium Medium [1, 2b] None (other than a residential [2b] care building or hospital)

Residential care building Medium Medium Medium None and hospital Shop Medium Medium Medium [2a] Medium [1] [2a]

Office Medium Medium Medium [1, 2d] None [2d]

Open sided car park Short Short None None

Additional information:

1.Short fire resistance duration is sufficient where the building is single-storey.

2.Short fire resistance duration is sufficient where the building is a multi-storey building and the area of any compartment does not exceed: (a) 500m² (b) 1000m² (c) 1500m²

(d)2000m² (e) 3000m² and (f) 4000m².

3.Short fire resistance duration is sufficient where the building is a factory (Class 2), and is single-storey.

4.No fire resistance duration is necessary where the building is a factory (Class 2).

2.6.2 Unprotected area

An unprotected area means any part of an external wall (including a door or window opening) which does not attain the appropriate fire resistance duration recommended in the table to clause 2.6.1.

An unprotected area does not include a fixed unopenable window where the frame and glazing has the appropriate fire resistance duration. Any wallhead fascia, soffit or barge board, or any cavity vents or solum vents may also be excluded from the unprotected area calculation.

Up to 500mm from boundary - where the external wall of a building is not more than 500mm from the boundary there should be no unprotected area, other than any wallhead fascia, soffit or barge board, or any cavity vents or solum vents.

500mm to 1m from boundary - where the external wall of a building is more than 500mm but not more than 1m from the boundary, the level of unprotected area is limited to:

a.the external wall of a protected zone

b.an area of not more than 0.1m², which is at least 1.5m from any other unprotected area in the same wall

c.an area of not more than 1m², which is at least 4m from any other unprotected area in the same wall (the 1m² unprotected area may consist of two or more smaller areas which when combined do not exceed an aggregate area of 1m²).

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More than 1m from boundary - where the external wall of a building is more than 1m from the boundary, the minimum distance to the boundary may vary with the amount of unprotected area. This is derived from the use of the building and can be calculated by:

•the Enclosing Rectangle (Geometric) Method as set out in clause 2.6.3, or

•the Building Research Establishment Report ‘External fire spread: building separation and boundary distances’ (1991, BR 187), or

•The simple Geometry method - if the building is a factory (Class 2), a residential building, an assembly building or an office and is not more than 9m in height and the length of any side facing the boundary is not more than 24m, the unprotected area (in square metres) is six times the distance (in m) to the boundary. For example, if the unprotected area is 6m², the distance to the boundary should be at least 1m and if the unprotected area is 12m², the distance should be at least 2m and so on. If the distance to the boundary is 6m or more, the amount of unprotected area is unlimited.

2.6.3 The Enclosing Rectangle Method

The Enclosing Rectangle Method can be applied to a building or compartment more than 1m from the boundary using the Step by Step Guide below. The minimum distance from the boundary may be arrived at by interpolation between the percentages shown in the tables.

Table A should be used for storage buildings, factories (Class 1), shops, and entertainment buildings.

Table B should be used for residential buildings, offices, assembly buildings, and factories (Class 2). Table B should also be used for domestic buildings which exceed the limitations described in clause 2.6.3 of the Technical Handbook for domestic buildings.

Automatic Fire Suppression system - where the building or compartment is a shop, entertainment building, factory (Class 1) or a storage building, Table B may be used instead of Table A provided the building:

•is located more than 1m from the relevant boundary, and

•an automatic fire suppression system is installed (see clause 2.1.2) within the building.

Open sided car parks - there is no limitation on the amount of unprotected area for an open sided car park provided the external wall is more than 1m from the boundary.

Step by step guide to Enclosing Rectangle Method

Step 1 - establish a plane of reference which is the most favourable for the side of the building under consideration and which:

a.touches all or part of the side

b.however far extended, does not pass within the building, but may pass through projections such as a balcony or coping, and

c.does not cross the relevant boundary.

Normally it will be best for the plane of reference to be roughly parallel to the relevant boundary. Where the boundary distance has not been set, an assumed relationship with the relevant boundary should be made.

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Figure 2.3 Enclosing Rectangle Method

Step 2 - on the plane of reference, and at right angles to it, project lines marking those o proposed unprotected areas which are 80 or less to the plane of reference. Any external side of a building which makes an angle of more than 80° with the plane of reference can be ignored in the calculation of unprotected area.

Step 3 - construct a rectangle which encloses all the unprotected areas projected onto the plane of reference following the diagrams below. See also clause 2.6.3 for combustible cladding.

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Figure 2.4 Diagram 2A - Setting Rectangle; Diagram 2B - 2D Determing size of rectangle

Step 4 - from the relevant table according to the use of the building or compartment, select an enclosing rectangle which is equal to, or next greater in both height and width to, the rectangle constructed under step 3. Compartmentation of the building can reduce the size of the enclosing rectangle in accordance with the diagrams below. The tables provide for enclosing rectangles of 3, 6, 9, 12, or 15m high, with widths in steps from 3m to no limit.

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Figure 2.5 Diagram 3A Uncompartmented; Diagram 3B Compartmented; Diagram 3C Compartmented

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Step 5 - from the unprotected areas projected under step 2:

a.calculate their total area, and

b.express this total area as a percentage of the enclosing rectangle. This gives the unprotected percentage.

Step 6 - proceed to steps 7 to 9 where the boundary distance has been set, or steps 10 to 12 where it has not.

To find the maximum unprotected area for a given boundary position.

Step 7 - from the tables below find the unprotected percentage allowed for the distance from the relevant boundary. This distance relates to the plane of reference and not the side of the building, unless they coincide.

Step 8 - where the proposed total unprotected area relative to the size of the enclosing rectangle exceeds the allowable unprotected percentage for that distance, the design should be modified until an allowable unprotected percentage is established, and

Step 9 - repeat the process for all sides of the building situated more than 1m from any point on the relevant boundary.

To find the nearest position of the boundary for a given building:

Step 10 - from the tables below, find the minimum allowable distance for the unprotected percentage. This distance relates to the plane of reference and not the side of the building, unless they coincide.

Step 11 - repeat the process for all sides of the building, and

Step 12 - where these minimum distances are superimposed upon a plan of the building, a zone around the building is established upon which a boundary should not encroach.

Table 2.7 Table A: Storage buildings, factories (Class 1), shops and entertainment buildings

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Additional information:

1.The minimum distance from the boundary may be arrived at by interpolation between the percentages shown.

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Table 2.8 Table B: Residential buildings, offices, assembly buildings and factories (Class 2)

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Additional information:

1.The minimum distance from the boundary may be arrived at by interpolation between the percentages shown.

2.6.4 External wall cladding

External wall cladding may contribute to the radiant heat flux from a fire and should be considered when calculating the amount of unprotected area. Additional guidance on External wall cladding systems is provided in the guidance to Standards 2.1, 2.2, 2.4, 2.7 and annex 2.E.

All situations – The use of highly combustible metal composite material panels referred to and defined in Regulation 8 of the Building (Scotland) Amendment Regulations 2022 is prohibited.

Not more than 1m from a boundary - External wall cladding not more than 1m from a boundary should achieve a European Classification A1 or A2 and can be excluded from the calculation of unprotected area.

More than 1m from a boundary - Fire within the building may break-out through a window or door opening and as a consequence, the cladding, once ignited, would contribute to the heat generated from the fire. Therefore where the cladding is more than 1m from a boundary and is constructed from products more than 1mm thick with a European Classification B, C, D or E (as described in annex 2.E), the cladding should be included in the calculation of unprotected area.

Storey height 11m or more above the ground - Regardless of the distance from the boundary, any external wall cladding system attached to a relevant building with a storey height 11m or more above ground must be constructed from products which achieve European Classification A1 or A2.

In addition, a cavity formed by external wall cladding should be protected in accordance with the guidance to Standards 2.1, 2.2, 2.4, 2.7 and annex 2.E.

2.6.5 Detached buildings in the same occupation

Notional Boundary - there may be a risk of fire spread between buildings even when on land in the same occupation. A notional boundary therefore is used to determine the safe distance between buildings or compartments in this situation. In order to establish whether a notional boundary calculation is necessary, the size of the opposing buildings or compartments should be established first (see diagram below).

For example, in the diagram, where the combined area of building A plus building B exceeds the maximum allowable area of any compartment as set in the tables to clause 2.1.1, then a notional boundary calculation is necessary. The designer is free to set this

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notional boundary at any point between the 2 buildings under consideration and this distance will determine the amount of unprotected area. The buildings should be separated by a distance not less than the sum of the distances calculated in respect of each building relative to a notional boundary in accordance with clauses 2.6.1 and 2.6.2, as if the notional boundary were a boundary (see diagram below).

Opposing compartments - a notional boundary is also necessary in the case of a single building having opposing compartments externally.

The roofs of the buildings should be separated by a distance not less than the sum of the distances provided in relation to the notional boundary in accordance with the guidance to Standard 2.8 in respect of each roof.

New and existing buildings - where a notional boundary, described above, is to be established between 2 buildings, one of which is an existing building, for the purposes of this guidance, the existing building should be regarded as if it were a new building.

Figure 2.6 Notional Boundary

2.6.6 Combustibility

Every part of an external wall including an external wall cladding system (see clause 2.7.1 and annex 2.E) not more than 1m from a boundary should be constructed of products which achieve European Classification A1 or A2. This does not apply to insulation exposed in a cavity that is between 2 leaves of masonry or concrete where both leaves are at least 75mm thick, and which has a cavity barrier around all openings in the wall and at the top of the wall-head.

Also, in shared residential accommodation, a structural frame and any thermal insulation material in the frame not more than 1m from a boundary may be constructed from combustible products provided:

•no storey height is more than 18m, and

•the recommendations in clauses 2.6.1 to 2.6.3 have been followed, and

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•any external wall cladding system (see clauses 2.6.4 and 2.7.1 and annex 2.E) is constructed from products which achieve European Classification A1 or A2.

See the guidance to Standards 2.1, 2.2, 2.4 and 2.7 for additional guidance in relation to cavities and external wall cladding systems.

2.6.7 Supporting structure

Where an element of structure provides support to an external wall (including external wall cladding) which has a fire resistance duration (as recommended in the guidance to clauses 2.6.1 and 2.6.2) the supporting element of structure should also have at least the same fire resistance duration.

2.7 Spread on external walls

Mandatory Standard

Standard 2.7

Every building must be designed and constructed in such a way, having regard to the height, use and position of the building, that in the event of an outbreak of fire within the building, or from an external source, the spread of fire on the external walls of the building is inhibited.

2.7.0 Introduction

There is a risk of fire spread on the external walls of a building. Fire could break-out through a window or door opening and spread onto the external walls. External walls close to the boundary are also at risk as they may be exposed to direct flame impingement or radiant heat flux from a fire in an adjoining building or other external source.

The use of highly combustible metal composite material panels referred to and defined in Regulation 8 of the Building (Scotland) Amendment Regulations 2022 is prohibited.

Entertainment and assembly buildings are given special consideration as a result of the Summerland fire in 1973).

Residential care buildings and hospitals also present a greater risk because the mobility, awareness and understanding of the occupants could be impaired and as a consequence, full evacuation immediately a fire is discovered may not be the most appropriate course of action.

Fire-fighters may not be able to apply a water jet from a fire-fighting hose directly onto a fire that has spread onto or within an external wall high above the ground. This is because the external wall is either inaccessible or is out with the reach capability of fire-fighting equipment. Therefore, the construction of external walls in taller buildings should not contribute to the development of fire or contribute to vertical fire spread up the facade of the building. The 11m storey height in Regulation 8 clause 2.7.1 and clause 2.7.2 is based on the reach capability of a fire and rescue service ground mounted water jet where there is sufficient pressure and flow in the water main. Designers are encouraged to seek early advice from the fire and rescue service if they wish to vary from the guidance where, for example, the façade is accessible to high reach appliances. Also, see Regulation 8 and annex 2.E for exceptions.

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The guidance for fire spread on external walls of buildings should not be assessed in isolation and reference should be made to the guidance to Standard 2.1 for compartmentation, Standard 2.2 for separation, Standard 2.4 for fire spread in cavities and the guidance to Standard 2.6 for fire spread to neighbouring buildings.

The Building Standards Futures Board has been established to improve the performance, expertise, resilience and sustainability of the Scottish building standards system. A key work stream currently under development is the creation of a Compliance Plan to ensure that designs, receiving a building warrant, are constructed in accordance with the building regulations and approved drawings. External wall cladding systems and specified attachments are considered safety critical features. In the interim, documented evidence of proof of compliance should be submitted to the local authority verifier which demonstrates that the system as approved has been constructed in accordance with the building warrant.

Green walls (also called living walls) have become popular in recent years. Best practice guidance can be found in ‘Fire Performance of Green Roofs and Walls’ published by the Department of Communities and Local Government.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirements of this standard in so far as is reasonably practicable, and in no case be worse than before the conversion (regulation 12, schedule 6).

2.7.1 External wall cladding systems

External wall cladding systems attached to relevant buildings having any storey at a height of 11m or more above the ground must be constructed of products which achieve European Classification A1 or A2 (see Regulation 8 and annex 2.E).

Relevant building - means a building having a storey, or creating a storey (not including roof-top plant areas or any storey consisting exclusively of plant rooms) at least 11m or more above the ground and which contains a:

•dwelling;

•building used as a place of assembly, or as a place of entertainment or recreation;

•hospital;

•residential care building or sheltered housing complex;

•shared multi-occupancy residential building.

External wall cladding systems - mean non load-bearing components attached to the buildings structure, for example, composite panels, clay or concrete tiles, slates, pre- cast concrete panels, stone panels, masonry, profiled metal sheeting including sandwich panels, rendered external thermally insulated cladding systems, glazing systems, timber panels, weather boarding and ventilated cladding systems. For the purposes of compliance with the building regulations and associated standards, external wall cladding systems also include spandrel panels and infill panels. Many systems incorporate support rails, fixings, thermal insulation, fire barriers and cavity barriers located behind the outer cladding.

Sheathing or backing board - attached to the frame to provide structural support is not considered to form part of the external wall cladding system. However, where combustible sheathing or backing board is proposed in any building with a storey 11m or more above the ground, a large scale facade fire test should be carried out (see annex 2.E).

Service penetrations - service penetrations such as flues, pipes, ducts or cables are not considered to be components forming part of an external wall cladding system.

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All situations – the use of highly combustible metal composite material panels referred to and defined in Regulation 8 of the Building (Scotland) Amendment Regulations 2022 is prohibited.

External wall cladding not more than 1m from a boundary should achieve European Classification A1 or A2.

External wall cladding more than 1m from a boundary should be constructed from products with a reaction to fire in accordance with the following table:

Table 2.9 Reaction to fire of external wall cladding more than 1m from boundary

Additional information:

1.Includes single-storey buildings

2.See exemptions in annex 2.E

3.Alternative approach as described in annex 2.E may be used

2.7.2 Specified attachments

There is a risk of vertical fire spread from specified attachments to an external wall including balconies, solar panels and solar shading. Fire-fighters may not be able to apply a water jet from a fire-fighting hose directly onto a fire that has spread onto specified attachments high above the ground.

Where a relevant building has a storey at a height of 11m or more above the ground, specified attachments must be constructed of products achieving European Classification A1 or A2.

Where a building (other than a relevant building) has a storey at a height of 11m or more above the ground, specified attachments should also be constructed of products achieving European Classification A1 or A2.

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Extendable and retractable solar shading products such as awnings and canopies are not considered to be fixed solar shading attachments within the context of Regulation 8.

However, awnings and canopies should still be considered on a risk based approach to assess the potential for vertical fire spread in accordance with Standard 2.7. For example, multiple canopies vertically aligned on every storey of building having a storey at a height of 11m or more above the ground possess a much greater risk of vertical fire spread compared with an awning or canopy located on the ground or basement storey only.

Signage is not considered to form part of an external wall cladding system or specified attachment.

2.8 Spread from neighbouring buildings

Mandatory Standard

Standard 2.8

Every building must be designed and constructed in such a way that in the event of an outbreak of fire in a neighbouring building, the spread of fire to the building is inhibited.

2.8.0 Introduction

Buildings are at risk from fires starting beyond their boundaries. The area of greatest vulnerability is the roof and there may be a risk of ignition or penetration by burning brands, flames or heat. The degree of protection for roof coverings is dependent upon the distance to the boundary.

A roof covering consists of one or more layers of material such as felt, tiles, slates, sandwich panels etc, but is not intended to include the whole of the roof structure. Solar roof panels should be regarded as forming part of the roof covering and as such should be able to resist ignition from an external source. Most solar panels are glazed and their ability to inhibit fire spread can be determined by the thickness of glazing which makes up the panel (see table to annex 2.F).

A roof covering or roof light which forms part of an internal ceiling lining should also follow the guidance to Standard 2.5 Internal linings.

Green roofs have become popular in recent years. Best practice guidance can be found in ‘Fire Performance of Green Roofs and Walls’ published by the Department of Communities and Local Government.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirements of this standard in so far as is reasonably practicable, and in no case be worse than before the conversion (regulation 12, schedule 6).

2.8.1 Roof coverings

The possibility of direct flame impingement from neighbouring buildings is greater where the roof covering of the building is close to the boundary. Whilst much will depend on the fire dynamics and the velocity and direction of the wind, burning brands are also likely to be more intense. For these reasons, the vulnerability of a roof covering is determined in relation to the distance of a building to the boundary.

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Not more than 6m from boundary - the roof of a building, including any rooflights, but excluding any wallhead fascia, flashing or trim, boxed gutters, soffit or barge boards, should have a low vulnerability if not more than 6m from the boundary. Common materials that normally attain the criterion include, slates, tiles, glazing, sandwich panels and certain plastic materials as described in Annex 2.F.

More than 6m but not more than 24m from boundary - the roof of a building, including any rooflights, but excluding any wallhead fascia, flashing or trim, boxed gutters, soffit or barge boards, should have a low or a medium vulnerability if more than 6m but not more than 24m from the boundary. Common materials that normally attain the criterion include felts and certain plastic materials as described in Annex 2.F.

More than 24m from boundary - where a building is more than 24m from the boundary, the roof may be of any material, including materials of high vulnerability classification.

2.9 Escape

Mandatory Standard

Standard 2.9

Every building must be designed and constructed in such a way that in the event of an outbreak of fire within the building, the occupants, once alerted to the outbreak of the fire, are provided with the opportunity to escape from the building, before being affected by fire or smoke.

2.9.0 Introduction

While the number of deaths from fires in non-domestic buildings is less than domestic buildings the potential for significant life loss and injuries is far greater. This is due to the large occupancy capacities that may be involved and the complexity of occupant behaviour including the potential for delay in occupant evacuation following the outbreak of fire.

Occupants in buildings do not normally perceive themselves to be at risk from fire and are not fully aware of the speed that fire can spread. The risk to occupants is greater if they are asleep during the outbreak of fire as their ability to detect a fire and to escape will be greatly impaired.

Everyone within a building should be provided with at least one means of escape from fire that offers a safe passage to a place of safety outside the building. This should allow for them to escape from the building before being affected by fire or smoke. In certain circumstances, for example, where the travel distance is excessive, a second means of escape should be provided. This will allow the occupants to turn away from the fire and make their escape in the other direction. There may be up to four stages in the process of escape:

•escape from the room of fire origin or escape from the fire where only one direction is possible

•escape from the compartment of fire origin or until the safety of a fire resisting wall is reached

•escape from the floor of fire origin to protected zones and escape stairs, and

•escape from the building to a place of safety at ground level.

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Due to the special fire precautions within residential care buildings, hospitals and enclosed shopping centres, additional guidance is provided in the annexes. However it is important to remember that the guidance in the annexes is in addition and supplementary to the guidance to Standard 2.1 to 2.15. For additional guidance on:

•residential care buildings, see annex 2.A

•hospitals, see annex 2.B

•enclosed shopping centres, see annex 2.C.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirement of this standard (regulation 12, schedule 6).

2.9.1 Escape principles

The occupants should be able to leave the building or part of the building in relative safety during the outbreak of a fire without assistance from the fire and rescue service.

Designers generally achieve this by providing independent routes of escape either directly to a place of safety, or through an adjacent compartment or protected zone.

The time available to leave a room or compartment of fire origin before being overcome by fire or smoke is dependant on a number of key factors:

•the number and mobility of occupants in the compartment or room of fire origin

•the containment measures of the room or compartment of fire origin

•the geometry of the room or compartment

•means of early warning of fire

•the fire dynamics (e.g. the fire load and the rate of fire growth)

•the distance to reach a place of safety, a protected zone or another compartment, and

•the number and width of exits.

There are many options available to designers when considering escape from buildings to a place of safety. However these options can be subdivided into 3 broad categories:

•direct escape

•internal escape

•external escape.

Direct escape means that occupants can escape from a building directly to a place of safety by way of a final exit door without using an internal or external escape route. Whilst direct escape to a place of safety is preferable, this is not always possible or convenient, for example, in hospitals or multi-storey buildings with many floors high above the ground.

Internal escape is perhaps the most common method of escape from buildings. Occupants escape from fire using enclosed corridors and stairs inside the building to reach a final exit door from the building, which leads to a place of safety.

External escape routes are wholly or partially open to the external air therefore the risk of smoke logging is reduced compared with enclosed escape routes inside the building. External escape routes include external escape stairs, access decks and flat roofs. In

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certain circumstances, an escape route from a building may be by way of a flat roof or an access deck.

2.9.2 Occupancy capacity

The use of a building and its occupancy capacity can vary considerably. It is necessary therefore to calculate the appropriate number of occupants in each space for normal circumstances.

The occupancy capacity can be estimated by assigning a floor area per occupant, this is called the occupancy load factor. The occupancy capacity of a room or space (without fixed seating) can then be obtained by dividing the area in square metres by the relevant occupancy load factor. While some buildings such as residential buildings are designed for a definitive number of occupants other occupancies such as in offices can vary.

The table below is based on the following characteristics of the occupancy:

•assembly and entertainment buildings, which may have high occupancy density and large undivided floor areas

•offices, where desks, cabinets and office machinery will be present

•shops, where display shelves, counters and racks will be present

•residential buildings, where the number of occupants is generally controlled by the number of beds available

•factory and storage buildings, where the occupancy capacity is normally low and goods or machinery will be present.

The values in the table can be used as a guide to assess the occupancy capacity of a room. Where the occupancy load factors listed in the table below are not used, a written statement of the occupancy capacity should be submitted to the verifier who may wish to confirm the figures (e.g. occupancy capacity may be based on the number of available seats; the figure should include the number of spaces available for wheelchair users).

Table 2.10 Occupancy capacity in rooms and spaces without fixed seating

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Additional information:

1.The occupancy capacity in enclosed shopping centres should be calculated in accordance with annex 2.C.

2.Shop sales area are classified as follows:

a.shop sales areas other than those listed in sub-clause 2(b) including supermarkets and department stores (all sales areas), shops for personal services such as hairdressing and shops for the delivery or uplift of goods for cleaning, repair or other treatment or for members of the general public themselves carrying out such cleaning, repair or other treatment

b.shop sales areas in shops trading predominately in furniture, floor coverings, cycles, perambulators, large domestic appliances or other bulky goods or trading on a wholesale self-selection basis.

3.The descriptions; arcade, hall, gallery and room used in the table do not indicate a particular design or configuration of building.

2.9.3 Travel distance

Travel distance is the term applied to the distance that occupants have to travel to a protected door and is measured along the actual route of escape from any point within a storey, including the distance across rooms.

The further occupants need to travel within a building to reach a protected door the greater the risk from the effects of fire. The travel distance should allow for the occupants to reach a protected door before being overcome by fire or smoke. This distance will depend on the nature of the fire and the characteristics of the occupants.

Occupants should be able to reach a protected door before there is a noticeable accumulation of smoke in the route of escape.

Therefore, to provide for safe evacuation of the occupants, it is necessary to have limitations on the distance occupants should have to travel to reach a protected door.

The limitations on travel distances reflect the different levels of protection that are necessary for the building occupants, based on the fire hazard and occupancy profile. The distances and available directions of travel, given in the following table and the guidance on travel distance, reflect this philosophy.

Table 2.11 Recommended travel distance (m)

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Additional information:

1.For additional guidance on residential care buildings, see annex 2.A.

2.For additional guidance on hospitals, see annex 2.B.

3.For additional guidance on enclosed shopping centres, see annex 2.C.

4.If the building also contains a room or auditorium with provision for fixed seating, the more demanding travel distances should be used.

5.In a silage or grain store on a farm where the material is handled primarily by mechanical plant, the distance is 30m.

2.9.4 Measurement of travel distance

Travel distance is the distance measured along the actual route of escape from any point within a storey to the nearest protected door giving direct access to:

•a place of safety, or

•another compartment, or

•a protected zone, or

•an external escape stair, or

•a flat roof or access deck, or

•to a door in a sub-compartment wall as described in annex 2.A and annex 2.B.

In the case of a building which has only 1 direction of travel, the travel distance should be measured to a protected door giving access to an escape stair or a place of safety. In the case of a building or part of a building where there are at least 2 available directions of travel, the travel distance may be measured to any protected door.

Obstructions - where a floor is divided by fixed seating or other fixed obstructions, the travel distance should be measured by way of the shortest route along open seatways, gangways or circulation areas.

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Internal stairs - where a measurement of travel distance includes an internal unenclosed escape stair, the travel distance should be measured along the pitch line from the centre of the nosing of the topmost tread to the lower landing, including the length of any intermediate landings.

2.9.5 Head room

An escape route and circulation area should have a clear headroom of at least 2m. In a doorway it may be reduced to not less than 1.9m.

2.9.6 Horizontal evacuation

In progressive horizontal evacuation, occupants within separate compartments remote from the fire may not need to evacuate the building. They may be able to remain within the building until the fire and rescue service has dealt with the fire or, if required, commence evacuation into an adjoining compartment or escape direct to the outside. The objective is to provide a place of relative safety within an adjoining compartment, from which further evacuation can be made if necessary but under less pressure of time.

Where the travel distance is measured to a protected door in a compartment wall:

1.there should be no fire shutter in that compartment wall, and

2.if the compartment does not contain either a final exit or direct access to a protected zone, then each of the adjoining compartments, should have at least 1 other escape route, which is not through a further compartment, and

3.the area of the adjoining compartment is:

•at least the sum, in m²; of the occupancy capacities of both compartments multiplied by 0.3, or

•the escape route width available from the adjoining compartment is sufficient for the sum of the occupancy capacities of both compartments.

A fire in any one compartment should not prevent the occupants of any other compartment area from reaching a final exit.

See annex 2.A for additional guidance on residential care buildings and annex 2.B for hospitals.

2.9.7 Number of exits

To assess the numbers of exits required from the storey, the occupancy of the whole storey must be assessed. There is no need however to include adjoining parts of the building where the adjoining part does not communicate with the part under consideration.

The evacuation time from a room or storey is controlled by the number of exits and the time taken for occupants to pass through the exits. The fewer and narrower the exit the longer it can take for occupants to leave a room or storey, this is liable to cause irritation among those waiting, which in an emergency may lead to panic and crushing. Exits must therefore be numerous and wide enough to discharge the occupants before such conditions occur.

The number of escape routes from a room or storey exits relates to:

a.the use and occupancy profile within the building

b.the occupancy capacity

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c.the height of a storey above the ground or the depth below ground, and

d.the travel distance involved.

To provide the occupants with the opportunity to move away from the effects of fire and smoke, on each storey of a building there should be sufficient exits to one or more of the following:

•an escape stair

•another compartment

•a protected zone, or

•directly to a place of safety.

In hospitals, the number of storey exits increase in proportion to the number of patient beds (see annex 2.B).

Room exits - it is important to realise that evacuating occupants from a building is dependant not only on the time it takes to reach an exit but also on the number that can be discharged through an exit in a given time. The tables below state the minimum number of exits that should be considered for a room depending on its occupancy capacity. For the purposes of this guidance, reference to a room shall include reference to a gallery, catwalk or openwork floor.

Table 2.12 Minimum number of room exits

The table below states the minimum number of exits that should be provided for a storey related to its occupancy capacity.

Table 2.13 Minimum number of storey exits

Additional information:

At least 2 storey exits should be provided from:

1.any storey at a height of more than 7.5m

2.any storey in a residential care building or hospital

3.a basement storey at a depth of more than 4.5m; or a basement storey which is intended to be used by members of the general public (other than a basement storey providing access only to sanitary accommodation).

Single escape stair - it is possible to design a building with part of the upper storey at a height of not more than 7.5m to have only one escape route where the remainder of the storey has two escape routes. In cases where escape is by way of a single escape stair, access to the escape stair should be by way of a protected lobby.

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Room exits to storey exits - where a room is located on a storey, which, due to the occupancy capacity, height of the storey or travel distance, is recommended to have 2 or more storey exits, the escape routes from the room exits to the storey exits should be designed as follows:

a.where only 1 room exit is provided, the escape route from the room should lead to 2 independent storey exits. However this need not be provided to:

•any room or space inside a protected zone enclosing an escape stair (see clause 2.9.24), or

•any room on a storey at a height of not more than 7.5m where the escape route provides access to a place of safety or to another compartment and the travel distance is designed in accordance with the guidance in clause 2.9.3 for one direction of travel.

b.where the occupancy capacity of a room is not more than 100, the room exits may give access to the same space provided the guidance for alternative directions of escape has been followed.

c.where the occupancy capacity of a room is more than 100, the room exits may also give access to the same space provided:

•the guidance for alternative directions of escape has been followed, and

•both escape routes are separated in the adjoining space by construction including a self-closing fire door, with a short fire resistance duration.

2.9.8 Escape route widths

To assist in the movement of occupants and reduce anxiety during an evacuation, escape routes should be wide enough to allow occupants to escape safely. The following recommendations for the width of escape routes are based on the speed and number of occupants that can move along an escape route together.

The aggregate unobstructed width in mm of all escape routes from a room, or storey, should be at least 5.3 x the occupancy capacity of the room or storey.

When a room or storey requires 2 or more escape routes, consideration should be given to the impact of one of the exits being affected by fire. The remaining exits, should be wide enough to allow all occupants sufficient time to leave the room or storey safely. Under these circumstances, when calculating the width of exits, the largest exits should be discounted. The aggregate width of the remaining exits need to be capable of accommodating the total number of occupants of the room or storey.

The guidance on the width of exits assumes a unit width of 530mm per person and a rate of discharge of 40 persons per minute. In theory a corridor 530mm wide would be capable of discharging 100 occupants in 2.5 minutes, but such a width would not allow occupants to move around freely and without difficulty, to the best of their ability. The unobstructed width of each individual escape route should be at least 1200mm to assist occupants with sensory, cognitive and/or mobility impairments. However where only stepped access is provided to a part of the building, the escape route may be reduced as follows:

•in buildings with not more than 225 occupants the minimum width may be reduced to 1100mm

•in buildings with not more than 100 occupants the minimum width may be reduced to 1000mm.

Doorways can reduce the width of escape routes by 150mm. This nominal reduction allows for the construction of door frames, however:

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•where the number of occupants using the escape route is not more than 225, the clear opening width of the doorway should be at least 850mm

•where the number of occupants using the escape route is not more than 100, the clear opening width of the doorway should be at least 800mm.

The clear opening width at doorways is measured in accordance with the diagram below:

Figure 2.7 Clear opening width at doorways

Constancy of width - an escape route should not narrow in the direction of escape. However an escape route may pass through a wider circulation area leading to a narrower circulation area provided the latter is of a width at least that recommended for the escape route. Width of escape stairs is covered in clause 2.9.31.

The strict application of the above guidance may not be appropriate in all cases as follows:

•a hospital, where staff will move bed patients into a safe area within the building, or

•enclosed shopping centres where the mall is regarded as a place of relative safety.

More detailed guidance for hospitals is provided in annex 2.B and for enclosed shopping centres in annex 2.C.

2.9.9 Direction of escape

Everyone within a room when confronted by an outbreak of fire should be provided with at least one means of escape that offers safe passage to an exit from that room.

A layout, which only follows the recommendations for travel distance and number of storey exits, may still result in an undesirable layout. For example if two exits are placed close together it may make it impossible for all occupants to reach either exit if the fire is close to the exits. It is essential therefore, that where more than one exit is provided they are located so that at least one exit is available.

In many cases, there will not be an alternative at the beginning of the route. For example, there may be only one exit from a room to a corridor, from which point escape is possible in two directions. This is acceptable provided the distance the occupants have to travel, to the point where they can diverge in two or more directions, follows the relevant guidance in clause 2.9.3 for one direction of travel, and the overall route to a protected zone or place of safety follows the recommendations for more than one direction of travel.

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Where more than one room exit is provided, the directions of travel from any point within the room should:

•diverge at an angle of at least 45°, or

•be combined for a distance not more than that allowed for one direction of travel and then diverge to two exits at an angle of at least 45° plus 2½° for every metre travelled in one direction (see table to clause 2.9.3).

To reduce the risk of 2 room exits becoming impassable due to fire or smoke in the early stages of fire growth, the distance between the exits from the room should be more than twice the distance travelled in one direction.

2.9.10 Escape from inner room

Occupants within an inner room could become trapped where there is an outbreak of fire in the adjoining access room. Therefore, escape should only be by way of one other room, and the inner room should:

•not be used as sleeping accommodation

•have an escape route that does not pass through more than one access room

•the access room should be fitted with a suitable automatic fire detection and alarm system to warn the occupants of the inner room of an out break of fire

•the access room should not be a place of special fire risk.

2.9.11 Fixed obstructions/furnishings

Storage areas of buildings with fixed obstructions should provide unobstructed access to an exit. Access to an exit in such buildings may be by way of a gangway. The width of gangways between fixed obstructions (including fixed racking or shelving and high-bay storage) should be at least 530mm. Due to the low occupancy and limited occupation in a building for the bulk storage of spirituous liquor, the width may be reduced to at least 400mm.

Fixed seating or furnishings - in a building, or part of a building, with fixed seating or fixed seating and fixed tables or other floor fixtures, there should be access to an exit by way of a gangway or a seatway, or a seatway directly to an exit; or a circulation area in accordance with the table and diagram below and:

•in the case of an auditorium that has more than 1 exit, at least 1 exit should be provided at least two-thirds of the distance from any stage, screen or performing area towards the back of the room, and

•a gangway or exit door should be provided at each end of a row of more than 12 fixed seats, and

•in the case of shops where the room, or part of the room, has an occupancy capacity of more than 100, the minimum width of a circulation area should be designed as if the circulation area were an escape route, or

•in the case of buildings to which the Safety of Sports Grounds Act 1975 applies, it is appropriate to use the Guide to safety at sports grounds http://www.culture.gov.uk.

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Figure 2.8 Plan of room with provision for fixed seating

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Figure 2.9 Method of measuring seatway widths

Table 2.14 Minimum width of gangways & seats in a room with fixed seating

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Additional information:

1.May be reduced to 900mm where the occupancy capacity of the room is not more than 60.

2.The travel distance should be measured by way of the shortest route along open seatways, gangways or circulation areas.

2.9.12 Escape routes in residential buildings

In residential buildings occupants are particularly vulnerable to fire when asleep. Occupants may also be unfamiliar with their accommodation and escape routes. Those occupants on the fire floor should be provided with the opportunity to reach a protected zone (or other escape route) in relative safety and as quickly as possible, therefore, the movement of fire and smoke to the escape route should be inhibited.

In a residential building, where any corridor escape route serves sleeping accommodation it should be constructed of walls providing a short fire resistance duration and any door in the wall should be a suitable self-closing fire door with a short fire resistance duration. However the fire door to the cleaners cupboard need not be self closing provided it is lockable.

This guidance may need to be adapted in a residential building used as a place of lawful detention due to the unique operational factors.

For additional guidance on residential care buildings and hospitals see annex 2A and 2B.

2.9.13 Fire and smoke control in corridors

The first hazard to occupants beyond the room of fire origin is likely to be from the products of combustion. Any migration of fire and smoke to an escape route may deter occupants from using it.

Every corridor, that is used as an escape route that exceeds the dimensions in the guidance below, should be:

•subdivided with a wall or screen with a short fire resistance duration, or

•protected by the installation of a smoke control system.

Where the corridor is subdivided by a wall or screen with a short fire resistance duration (insulation criteria need not be applied) any door in the wall or screen should be a self- closing fire door and:

•where the corridor is a dead end more than 4.5m long and provides access to a point from which more than 1 direction of escape is possible, it should be divided at that point or points, as shown in the diagram below and

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•where the corridor provides at least 2 directions of escape and is more than 12m in length between the exits it serves, it should be divided in the middle third of the corridor. This does not mean that the corridor should be subdivided into 12m lengths.

Figure 2.10 Corridor division

Where a cavity extends across any of the self closing fire doors identified above, or above the walls described in clause 2.9.12 a cavity barrier with at least short fire resistance duration should be fitted above the sub-dividing wall and fire door to inhibit fire and smoke spread.

Smoke control systems - when a design incorporates a smoke control system in a building, other than a residential care building or hospital, it should employ smoke differentials. More detailed guidance can be found in the BS EN 12101 series of standards, but assuming a minimum pressure difference (over the wall being assessed) of 25 Pa based on a wind speed of 22m/sec. Mechanical smoke ventilation using pressure differentials may be used to inhibit smoke spread into escape routes by means of:

•depressurisation systems, or

•pressurisation systems.

The merits and limitations of each system should be assessed before deciding which system to choose.

A depressurisation system is based on the principle of extracting smoke to the outside air. This creates a negative pressure in the space relative to the adjacent spaces. Where a smoke ventilation depressurisation system is used, replacement air should be provided for the system to operate effectively. The volume of air and smoke removed should be replaced with the equivalent volume of replacement air at a sufficient rate in order to ensure a smoke flow out of the building. Reducing the rate of replacement air can result in the smoke ventilation system becoming less efficient whereas increasing replacement air and extraction at high velocities can produce air pressure conditions which make doors difficult to open. The system should be balanced to ensure that the forces required to open doors are not greater than those specified in Section 4 Safety.

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A pressurisation system is based on the principle of forcing air into the escape route which helps to keep smoke out. Forced air can be used to maintain a positive pressure in the escape route which produces an air flow through gaps around doors preventing the smoke from entering. The system design should take account of likely pressure reduction when occupants open doors to escape or when fire-fighters open doors to access the fire. The system should be balanced to ensure that the forces required to open doors are not greater than those specified in Section 4 Safety.

2.9.14 Openings in floors

In the event of a fire, there is always a risk that an opening in a floor could result in a proportion of fire or smoke and toxic fumes arising from a fire flowing up through the opening leading to a build-up of smoke on the upper storeys. This can pose a threat to life safety, particularly when the occupants are unfamiliar with the building. Smoke and flames rising through such an opening in a floor may impede evacuees from leaving the building. It is important when such a design is considered that it does not impair the ability of the occupants to escape. Occupants should be able to move directly away from the opening or continue their evacuation at a safe distance away from the edge of the opening.

Escape routes should not be compromised by openings between floors, such as at an escalator and fire safety measures are necessary to compensate for this increased level of hazard; the diagram below explains this principle.

In a building where there is an opening in any floor, not being a compartment floor or separating floor, an escape route should not be within 4.5m of the openings unless:

•the direction of travel is away from the opening, or

•there is an alternative escape route, which does not pass within 4.5m of the opening, or

•a wall or screen with a short fire resistance duration for integrity is provided between the opening and the route of escape.

Figure 2.11 Openings in floors

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Time can be a critical factor in ensuring occupants can leave the building before being overcome by the effects of fire and smoke. It is important therefore that an escape route provides a clear unobstructed route that does not restrict the flow of occupants.

To ensure the safe and smooth movement of occupants and prevent unnecessary increase in anxiety during an evacuation the following should not be part of an escape route:

•a lift, or

•an escalator, or

•a turnstile, other than a suitably designed and installed turnstile unit with an emergency break out facility enabling the entire unit to open in the direction of escape, or

•any shutter; other than one which is installed for security purposes across a shop front and which does not close automatically in the event of fire, or

•a manual sliding door, accessible to the public.

A fixed ladder may be used to escape from a plant room (not being a place of special fire risk), which is unoccupied other than for maintenance purposes.

Revolving doors and automatic doors can obstruct the passage of persons escaping. However they may be installed in an escape route if designed and installed in accordance with BS 7036: 2014 and are either:

•arranged to fail safely to outward opening from any position of opening, or

•provided with a monitored fail-safe system for opening the door from any position in the event of mains supply failure and also in the event of failure of the opening sensing device, and

•opens automatically from any position in the event of actuation of any fire alarm in the fire alarm zone within which the door is situated.

2.9.16 Direction of door openings

Doors across an escape route can slow the flow of occupants and may lead to crowding. To ensure that doors on an escape route do not unduly delay escape they should open in the direction of escape. However doors across an escape route may open against the direction of escape where the occupancy capacity in the building, or part of the building is low as follows:

•in a factory building or storage building where the occupancy capacity is not more than 10

•in any other building where the occupancy capacity is not more than 60.

However if the door is an emergency door or a door serving a place of special fire risk, the side-hung door should open in the direction of escape regardless of occupancy levels.

2.9.17 Galleries

For the purposes of compliance with this standard a gallery is an integral part of the room into which it projects, and the occupants of a gallery would have the same awareness of an outbreak of fire in a room as the other occupants of that room. The limitations on the size

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of a gallery relative to the room into which it projects is to provide those occupants on the gallery with the same awareness of any outbreak of fire.

The safety of those using a gallery, relates to:

•the use and occupancy characteristics within the room, and

•the occupancy capacity, and

•the travel distance, and

•the number of escape routes.

A gallery should be open above and below to the room into which it projects and should not give access to any other room, other than a room with a means of escape independent of the gallery. The gallery may be wholly or partly enclosed below, where:

•the floor of the gallery has a short fire resistance duration, and

•at least 1 route of escape from the gallery is by way of a protected door.

2.9.18 Locks

Locks on exits doors or locks on doors across escape routes present difficulties when assessing the need for security against the need to allow safe egress from a building in the event of a fire. Security measures however should not compromise the ability of the occupants to escape from a building in an emergency.

In general, all doors on escape routes, should either not be fitted with locks, or they should only be fitted with fastenings that can be readily operated from the side approached by occupants making an escape. The operation of these locks should be readily apparent, without the use of a key or access control tokens and without having to manipulate more than one mechanism. This is not intended to prohibit the use of locks to secure a room, storey or building when unoccupied. This guidance may also need to be adapted in a building used as place of lawful detention due to the unique operational factors.

Where an exit door from a room, storey or a door across an escape route has to be secured against entry when the building or part of the building is occupied, it should only be fitted with a lock which is readily operated, without a key, from the side approached by occupants making their escape. Similarly, where a secure door is operated by a code, combination, swipe or proximity card, biometric data or similar means, it should also be capable of being overridden from the side approached by occupants making their escape (see also electrically operated locks).

Guidance on the types of hardware for timber fire and escape doors can be obtained from the Code of Practice, 'Hardware for Fire and Escape Doors' Issue 4, November 2012, published by the Door and Hardware Federation and the Guild of Architectural Ironmongers.

2.9.19 Mechanical or electro-mechanical panic exit locking devices

Different groups of users will have differing needs to enable them to escape quickly and easily from a building in the case of fire and this should be reflected in the type of lock chosen. For example, in buildings frequented by the general public it is important that the locks can be released by occupants who may be unfamiliar with the building and have received no training in the emergency procedures or the types of exit locks used in the building.

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These locks are designed to operate on body pressure alone and require no knowledge of their operation to enable safe and effective evacuation of the building. In these cases, panic exit locks operated by a horizontal bar should be designed and installed in accordance with BS EN 1125: 2008.

2.9.20 Mechanical or electro-mechanical emergency exit locking devices

In buildings, or parts of buildings, that are not open to the general public, such as in offices or other working environments, the occupants should be awake and familiar with the building. When staff in such areas are trained both in the emergency procedures and in the use of the specific emergency devices fitted (see clause 2.0.8) then emergency exit devices to BS EN 179: 2008 can be installed. This type of locking device is released mechanically by a single action applied to the door lever handle or push pad to allow people familiar with the building to escape in an emergency.

Locking devices to BS EN 179: 2008 can also be used in buildings or areas used by the general public where the occupancy capacity is low. Therefore these devices should not be installed on any door accessible to the general public where the aggregate occupancy capacity of the rooms or storeys served by the door is more than 60 persons.

2.9.21 Electric locking devices that unlock on electrical power being withdrawn

Where there is a choice of escape routes and the doors on one direction of escape are fitted with devices giving mechanical escape which operate on body pressure alone to BS EN 1125: 2008 or by the use of a lever handle or push pad to BS EN 179: 2008, the alternative escape route could be fitted with fail unlocked, electric locking device, such as an electro-magnetic lock. These are devices that require electrical power to be withdrawn from them to unlock.

Fail unlocked, electric locks, may be installed on exit doors and doors across escape routes, which are inaccessible to the general public or, on any door accessible to the general public where the aggregate occupancy capacity of the rooms or storeys served by the door does not exceeds 60 persons.

Where the locks are intended to be used by occupants who are familiar with the building, staff in such areas, will need to be trained both in the emergency procedures and in the use of the specific locking devices fitted (see clause 2.0.8). Fail unlocked devices are not designed to be used by people in a panic.

Where installed in buildings that feature fail unlocked electric locks, they should operate in conjunction with a fire alarm system, the design of which should be determined by a fire risk assessment (see clause 2.0.8).

More detailed guidance on the type of fire alarm system most appropriate to the circumstances is contained in BS 5839: Part 1: 2017.

This type of ‘fail unlocked electric locking device’ should unlock instantly when electrical power is withdrawn and should unlock even when pressure is being applied to the escape door by occupants trying to escape at the time that electrical power is withdrawn.

‘Fail unlocked electric locks’ should not be installed on:

•a protected door serving the only escape stair in the building (or the only escape stair serving part of the building), or

•a protected door serving a fire-fighting shaft, or

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•on any door which provides the only route of escape from the building or part of the building, or

•on any door accessible to the general public where the aggregate occupancy capacity of the rooms or storeys served by the door exceeds 60 persons.

A delay in the opening of a door across an escape route, can lead to an increase in anxiety of occupants or possible panic. Therefore ‘fail unlocked electric locks’ should be programmed to fail to the unlocked position:

•on operation of the fire alarm system

•on loss of electrical power or system error

•on activation of a manual door release unit (Type A) to BS EN 54: Part 11: 2001 they are connected to, positioned at the door on the side approached by occupants making their escape and where the door provides escape in either direction, a unit should be installed on both sides of the door.

Some electric locking devices fail locked on both sides of the door when electrical power is withdrawn and does not give mechanical escape by panic bar, handle or push pad. This type of electric locking should not be used on exit doors and doors across escape routes.

2.9.22 Auditoria

In a building containing an auditorium, a ventilation system should be provided above all stages so that in the event of fire the occupants can escape before being overcome by the effects of fire or smoke. The ventilation system should be designed in such a way that the direction of air movement in the event of fire is from the auditorium towards the stage. Ventilation may be provided by means of mechanical extract ventilation or by natural ventilation direct to the external air, additional guidance is provided in BS 5588: Part 6: 1991.

Escape from the part of the stage behind the safety curtain should be independent from that of the auditorium.

Ancillary fire hazard rooms in the stage area, such as scenery dock, workshop, stage basement, staff or other rooms associated with the stage should where reasonably practicable be enclosed by a construction with a short fire resistance duration.

In a building containing an auditorium having an occupancy capacity of more than 500, additional passive and active fire safety measures should be provided and any stage should be separated from the remainder of the building by walls of medium fire resistance duration.

However this does not apply to the following:

•the proscenium opening, provided there is a safety curtain which conforms to BS 5588: Part 6: 1991, and

•an open stage.

Any door openings in the proscenium wall other than the proscenium opening should be provided with protected lobbies with short fire resistance duration.

Where a stage is equipped with a safety curtain, a high level outlet over the stage and stage area should be provided to allow the safety curtain system to operate effectively by containing fire and smoke to the stage and to allow the escape of smoke and hot gases in the event of a fire on the stage.

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Where a building has an open stage the smoke exhaust system should be sized to keep the auditorium relatively clear of smoke during the period of evacuation. Extract ventilation should preferably be taken from high level positions to assist in keeping the main auditorium clear of smoke. The size and performance of the smoke exhaust system will depend upon the size of the stage. Unless determined otherwise by a fire engineering calculation, natural exhaust ventilators over an open stage should have a combined total aerodynamic free area of at least 10% of the area of the stage.

Each case should be considered separately to ensure that smoke will not be transferred from one area to another, particularly where there are distinctly separate entertainment areas, which share common escape routes.

2.9.23 Protected lobbies

A protected lobby is located within a protected zone and is designed to inhibit the movement of fire and smoke from an adjoining room, storey or space into the escape stair or fire-fighting lobby. This is normally achieved by fire resisting construction together with at least 2 sets of self-closing fire doors between the fire and the escape stair or fire-fighting lobby.

Protected lobbies in non-domestic buildings are used:

•to inhibit fire and smoke spread to escape stairs

•to help occupants escape past the floor of fire origin

•to provide a protected route of escape from the fire floor

•to reduce the number or width of escape stairs in a building

•to provide a relatively safe space for the fire and rescue services to set up a forward control point and to provide a bridgehead from which to commence operations (see Standard 2.14).

Buildings with 1 Escape route - occupants in buildings with only 1 escape route are at greater risk from being exposed to fire and smoke during their escape. Therefore, where a building has only 1 escape route by way of an escape stair, access to the escape stair should be by way of a protected lobby. However, protected lobbies need not be provided to shared residential accommodation.

There is less risk in low rise non-residential buildings with low occupancy numbers, which have a fire warning and detection system installed as this should provide the occupants with sufficient time to escape. The occupants of such buildings should be awake, and have less distance to travel. Therefore, a protected lobby need not be provided where the building:

•is a non-residential building with no more than 300 occupants, and

•no storey is at a height of more than 7.5m, and

•an automatic fire detection and alarm system is installed in the building as recommended in BS 5839: Part 1: 2017 to Category L1.

Occupants in tall buildings will take longer to escape from the building and are therefore at greater risk from being exposed to fire and smoke during evacuation. There is also the risk that more than 1 escape stair could be affected by fire or smoke. Therefore, in every building having a storey at a height of more than 18m above ground level, access to the protected zone containing the escape stair should be by way of a protected lobby. When a protected lobby is provided, the wall dividing a protected lobby from the remainder of the protected zone should have a short fire resistance duration for integrity only and any door

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in the wall should be a self-closing fire door with a short fire resistance duration. However see Standard 2.14 for fire and rescue service facilities.

2.9.24 Protected zones

A protected zone may or may not contain an escape stair and is intended to protect occupants during their evacuation to a place of safety.

Protected zones should be designed and constructed to withstand fire in an adjoining room or space. The protected zone should form a complete enclosure having at least a medium fire resistance duration. Every door in the wall of a protected zone should be a self-closing fire door with a medium fire resistance duration. However the floor of the lowest storey or an external wall (other than an external wall described in clause 2.9.36) need not be fire resistant.

A protected zone in shared residential accommodation should have at least short fire resistance duration.

As a building becomes taller the distance to be travelled and time taken for the occupants to reach a place of safety increase. Therefore in buildings with any storey at a height of more than 18m, the enclosing structure of the protected zone should have long fire resistance duration on all storeys.

The accommodation within every protected zone should be limited to places where fire is unlikely to start. As the fire risk is considered low, a cleaners cupboards of not more than 3m² and toilets or washrooms may be sited in the protected zone.

In buildings with 2 or more protected zones, the occupants have an alternative route out of the building if one of the protected zones was affected by fire or smoke. A reception room, an office and a general store room, each of not more than 10m² may be located within the protected zone as they are of limited size and the potential fire load is low.

The wall separating the rooms/cupboards from the protected zone should have a short fire resistance duration and any door in the wall should be a self-closing fire door. A door to a cleaner’s cupboard need not be self-closing provided it is lockable. The walls/ doors separating the toilets or washrooms from the protected zone need not have a fire resistance duration.

2.9.25 Enclosure of escape stairs

To protect occupants from fire and smoke when evacuating a building, an escape stair should be within a protected zone. However this is not necessary in the following situations:

•an escape stair which connects 2 or more levels within a single-storey where the difference in level between the highest and lowest level is not more than 1.8m, or

•an external escape stair with a total rise of not more than 1.6m, or

•an external escape stair constructed in accordance with clause 2.9.37

•an escape stair, from a gallery, catwalk (including lighting bridges), or openwork floor where they have:

a.an occupancy capacity of not more than 60, or

b.an occupancy capacity of more than 60 but not more than 100 and at least 1 route of escape is by way of a protected zone, an external escape stair or to another compartment. Where the occupancy capacity is more than 100 the escape stair should be enclosed within a protected zone.

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Due to a very high fire risk, with potential for rapid fire growth, a place of special fire risk should only be accessed from a protected zone by way of a protected lobby. This is to give additional protection to the protected route of escape.

2.9.27 Openings and service penetrations

Fire and smoke can easily pass through openings in protected routes of escape (see clause 2.0.6) which could prevent the occupants from escaping in the event of an outbreak of fire within the building. For this reason, the openings in protected routes of escape should be limited to openings such as smoke ventilation systems, chimneys, flue-pipes, self-closing fire doors and service openings, fire shutters or dampers.

It is important that ducted heating and ventilation systems including air conditioning systems, installed to maintain interior environment conditions, that serve the building should not transfer fire and smoke to or from; any compartment to any other compartment, escape route, common space, roof space or other concealed space. Therefore, in the event of an outbreak of fire, the system should automatically either shut off, or operate in smoke control mode. For more detailed guidance refer to BS 5588: Part 9: 1999.

In order to inhibit the spread of fire and smoke, the openings should be protected and fire stopped in accordance with the guidance to Standard 2.1.

2.9.28 Junctions

The junctions between protected routes of escape (see clause 2.0.6) and other parts of the building are vulnerable to fire and smoke. This is because fire and smoke can penetrate weaknesses at junctions which could compromise the means of escape. The designer should consider detailing at junctions to inhibit fire and smoke spread into the protected route of escape.

Where part of a building is a protected route of escape and forms a junction with any other part of the building including for example, an external wall, a separating wall, another compartment wall, or any other wall or screen forming a protected route of escape, the junction should maintain the fire resistance duration of the more demanding guidance.

In order to inhibit the spread of fire and smoke, junctions should be protected in accordance with clause 2.1.15 and for additional guidance on fire-stopping materials, see clause 2.1.14.

2.9.29 Fuel pipes

Pipes conveying fuel inside protected zones could accelerate fire growth and under certain conditions, create an explosive atmosphere within the building. Oil and liquefied petroleum gas can produce pool fires, i.e. a turbulent fire burning above a horizontal pool of vaporising hydrocarbon fuel. The pool fire can be either static e.g. where the pool is contained or a ‘running’ pool.

Fuel pipes carrying oil (other than a pipe conveying oil supplying a hydraulic lift) should be located outside protected zones. A pipe conveying oil supplying a hydraulic lift may be located inside a protected zone. Fuel pipes carrying natural gas or liquefied petroleum gas (including associated meters) may be located within a protected zone provided:

•the installation is in accordance with the requirements of the Pipelines Safety Regulations 1996, SI 1996 No 825 and the Gas Safety (Installation and Use) Regulations 1998 SI 1998 No 2451, and

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•any pipe is constructed of screwed steel or welded steel construction, and

•the pipe or pipes are contained within a service shaft with at least a medium fire resistance duration from the outside, and

•the service shaft is ventilated at high and low level in accordance with BS 8313: 1997.

2.9.30 Temporary waiting spaces

The speed of evacuation of occupants with sensory, cognitive and/or mobility impairments can be much slower than other building users. Therefore, a space should be provided to allow them to wait temporarily, before completing their escape to a place of safety.

The safe evacuation of occupants with sensory, cognitive and/or mobility impairments is the responsibility of the employer or other person having control of the building and not that of the fire and rescue service. Therefore, occupants with sensory, cognitive and/or mobility impairments, should not be directed to remain in these spaces awaiting the arrival of the fire and rescue service. The employer or other responsible person should make the necessary arrangements for the safe evacuation of all occupants from the temporary waiting spaces.

The duty holder also has a duty under the Management of Health and Safety at Work Regulations 1999, to assess the risks to workers and any others, who may be affected by their work or business. Further requirements under the Fire (Scotland) Act 2005 and the Fire Safety (Scotland) Regulations 2006, in respect of fire safety risk assessment and further obligations in respect of fire safety measures must also be considered.

Temporary waiting spaces should have an unobstructed clear area capable of accommodating a wheelchair and measuring at least 700mm x 1200mm. They should be located in either:

•a protected lobby, or

•a protected zone, or

•an external escape stair, or

•an adjacent compartment.

However it is not necessary to provide a temporary waiting space in a protected zone where the storey has level or ramped egress to a place of safety or on an external escape stair with a total rise of not more than 1.6m.

To assist the escape process and reduce the anxiety of occupants making use of the space, an emergency voice communication (EVC) system should also be provided in the designated temporary waiting space.

The EVC should follow the guidance in either:

•BS 5839: Part 9: 2011 and consist of type B outstations and communicate with a master station located in the building control room (where provided) or adjacent to the fire alarm panels, or

•in some buildings, it may be more appropriate to use alternative two way communication that can be readily operated by occupants in the temporary waiting space.

2.9.31 Escape stair widths

Every escape stair should be wide enough to accommodate the number of occupants needing to use it in an emergency and allow them to make their escape before being overcome by the effects of fire and smoke. This width will depend on the number of stairs

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provided and whether the escape strategy for the building (or part of the building) is based on:

•simultaneous evacuation, or

•phased evacuation.

Minimum effective width - to help limit the potential for queuing at the storey exit which in an emergency may lead to panic and crushing, the effective width of an escape stair should be at least the width of any escape route giving access to it. Therefore the effective width of each escape stair should be at least 1200mm to assist occupants with sensory, cognitive and/or mobility impairments. However where the building has limited occupancy numbers the escape stair width may be reduced as follows:

•1100mm where the number of occupants using the stair is not more than 225, and

•1000mm where the number of occupants using the stair is not more than 100.

The effective width of an escape stair is measured between handrails and clear of obstructions.

Where the number of occupants using the escape stair is more than 225 then the formula for calculating the effective width of the stair should be used. The escape stair should not narrow in the direction of escape.

Appropriate capacity - to assist the verifier and designer establish the width of an escape stair, it is necessary to establish the number of escape stairs and the number of occupants who will access them on each storey. The effective width of escape stairs is based on the number of occupants who will use each escape stair and the resultant figure is known as the appropriate capacity (AC). The methodology for calculating the appropriate capacity must also take into account whether a building has been based on simultaneous or phased evacuation.

Simultaneous evaluation - in a building designed on the basis of simultaneous evacuation the escape stairs (in conjunction with the rest of the means of escape) should have the capacity to allow the occupants of all storeys to evacuate at the same time.

The appropriate capacity in relation to an escape stair at any storey above or below the adjacent ground is calculated by one of the following methods.

Where the escape stair serves only one storey, the appropriate capacity equals the occupancy capacity of the storey served by the escape stair (see diagram below). The appropriate capacity for the storey should then be used in the formula for calculating the effective width of the escape stair.

Figure 2.12 One storey example

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In a building in which the escape stair serves more than 1 storey the appropriate capacity for each storey should be calculated and the total appropriate capacity for all the storeys served by the escape stair should then be used in the formula for calculating the effective width of the escape stair. A deduction of 20% from the appropriate capacity is allowed for the number of occupants who could be standing in the stair.

This method of calculating the escape stair width can be used to reduce the width of the stair as it rises up the building although this would not be a typical form of construction.

Figure 2.13 More than one storey example

Phased evacuation allows occupants most at risk to be evacuated first. This allows the designer to reduce the width of the escape stairs and minimises disruption in large buildings. Tall buildings take longer to evacuate and where the building is at a height of more than 25m it is beyond the reach capability at which Fire and Rescue service can effect external rescue. Therefore, when phased evacuation is adopted in buildingsadditional active and passive fire protection measures will be necessary.

As phased evacuation relies on some occupants remaining where they are until instructed to leave, it is only suitable for buildings where the occupants are awake and familiar with the building, for example, offices.

The occupants first evacuated are those on the storey of fire origin and those on the storey immediately above. If further evacuation is required this is done on the basis of the next two adjoining upper storeys to avoid congestion in the escape stairs. The remaining storeys would then be evacuated two storeys at a time however this would be dependent on the severity of the fire and any direction given by the fire and rescue service.

Because of the additional time it may take to evacuate a building or part of a building where the means of escape is based on vertical phased evacuation, the following fire safety measures should be provided:

•installation of an automatic fire detection and alarm system to BS 5839: Part 1: 2017, Category L2, and

•a voice alarm should be installed in accordance with BS 5839: Part 8: 2013. Such a system enables two or more stages of alarm to be given within a particular area, and

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•the escape stairs should be entered from a protected lobby, and

•every storey should be a compartment storey, and

•if the building has any storey at a height of more than 25m, every storey should be protected by an automatic life safety fire suppression system (see guidance to Standard 2.15), and

•an internal speech communication system should be provided via a control point at the access level to allow the fire and rescue service to converse with a fire warden on every storey.

In a building where the stairs have been designed on the basis of vertically phased evacuation the appropriate capacity [AC] in relation to an escape stair at any storey above or below the adjacent ground is calculated by the following method and in accordance with the diagram below.

In a building, or part of a building, which is divided by one or more compartment floors, the appropriate capacity [AC] is equal to, the total occupancy capacity, less 20%, of each of the 2 adjacent upper storeys, served by the escape stair, or in the case of an escape stair serving a basement storey, the 2 adjacent basement storeys served by that escape stair, having in either case the greatest combined occupancy capacity.

Figure 2.14 Compartmented building example

Calculation of effective width - based on the above principles for simultaneous and phased evacuation, the effective width of every escape stair in mm can be calculated by the following formula:

Where:

•EW is the effective width of an escape stair measured in mm between handrails and clear of obstructions

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•AC is the appropriate capacity, which in relation to an escape stair is the occupancy capacity of the storey served by the escape stair, less 20%

•N - 1 is the number of escape stairs minus 1, unless it meets exception for protected lobbies above

A deduction of 20% from the appropriate capacity is made to allow for the number of occupants who could be standing in the stair.

Before using the formula it is necessary to consider the possibility that one stair may be affected by fire or smoke before all occupants have evacuated the building. For that reason one stair should be discounted for calculation purposes, unless a protected lobby is provided on every storey between each escape stair in a protected zone and any part of the building at any storey from which there is access to the escape stair.

If the escape stair contains any of the rooms listed in clause 2.9.24 the stair should be discounted from the stair width calculation.

Example 1 - simultaneous evacuation

What is the minimum effective width needed for escape stairs in an office building with 4 storeys and 2 escape stairs and which escape is based on simultaneous evacuation? For this example it is assumed that the occupants are distributed evenly across each storey, therefore the number of occupants will be split evenly to each escape stair.

There are 100 occupants on the top storey, 150 occupants on the 2nd storey and 200 occupants on the 1st storey. The escape routes on the ground storey do not communicate with the escape stairs.

It is assumed that the buildings do not have any protected lobbies, therefore the effective width equals:

AC is the appropriate capacity and is the sum of the occupancy capacity of the storeys served by the escape stair minus 20% for standing capacity in the stair:

Top storey = 100 x 0.8

2nd storey = 150 x 0.8

1st storey = 200 x 0.8

AC = 360

=

The minimum width of each escape stair will be 1908mm.

Example 2 - simultaneous evacuation

What is the minimum effective width needed for escape stairs in an office building with 6 storeys and 3 escape stairs and which escape is based on simultaneous evacuation. For this example it is assumed that the occupants are distributed evenly across each storey, therefore the number of occupants will be split evenly to each escape stair.

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Each storey has 300 occupants and the escape routes on the ground storey do not communicate with the escape stairs.

It assumed access to each protected zone containing the escape stair is by way of a protected lobby. Therefore, there is no need to deduct 1 stair from the calculations:

AC is the appropriate capacity and is the sum of the occupancy capacity of the storeys served by the escape stair minus 20% for standing capacity in each of the stairs.

There are 5 storeys accessing the escape stair and each storey has 300 occupants the appropriate capacity is found by:

AC = 300 x 5 x 0.8

AC = 1200

=

The minimum width of each escape stair will be 2120mm.

Example 3 - phased evacuation

What is the minimum effective width needed for escape stairs in an office building with 10 storeys and 3 escape stairs and which escape is based on phased evacuation. For this example it is assumed that every storey is a compartment storey and that the occupants are distributed evenly across each storey, therefore the number of occupants will be split evenly to each escape stair.

Each storey has 300 occupants and the escape routes on the ground storey do not communicate with the escape stairs.

As escape is based on phased evacuation, access to each protected zone containing the escape stair should be by way of a protected lobby. Therefore, there is no need to deduct 1 stair from the calculations:

AC is the appropriate capacity of each of the 2 adjacent upper storeys, with the greater occupancy capacity, minus 20% for standing capacity in each of the stairs:

AC = (300 x 0.8) + (300 x 0.8)

AC = 480

=

EW = 848mm

However as the effective width of each escape stair should be at least 1200mm all 3 stairs should be at least 1200mm wide.

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Combined escape routes - where escape routes from a storey consist of a combination of escape stairs and other escape routes (see diagram below) the effective width of any escape stair from that storey should be designed to take into account that proportion of the number of occupants on that storey who may escape by way of the other escape routes.

The escape route should be sized to take account of all the occupants who will be escaping. Therefore, where the escape route from an escape stair is also the escape route from the ground storey and/or basement storey, the width of that escape route should be increased to take account of that proportion of the occupancy capacity from the ground storey and/or basement storey.

Figure 2.15 Combined escape example

2.9.32 Independence of escape stairs

Where there are alternative escape stairs from a storey, there is the risk that one of the escape stairs could be smoke logged preventing access through to the alternative escape stair. Where a room or storey needs two or more escape stairs, it should be possible to reach 1 alternative escape stair without passing through the other.

When the escape stairs are adjacent to one another, to reduce the likelihood of them becoming smoke logged at the same time, for example, where the protected zones enclosing escape stairs share a common wall, any access between them should be by way of a protected lobby.

2.9.33 Escape routes in a central core

To reduce risk of smoke spread to more than 1 escape stair, corridor or lobby, a building with more than 1 escape route contained in a central core, should be planned so that the exits from the storey are remote from one another, and so that no 2 exits are approached from the same lift hall, common lobby or undivided corridor or linked by any of these other than through self-closing fire doors.

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Figure 2.16 Central core example

2.9.34 Escape stairs in basements

The limited natural ventilation available in a basement can lead to rapid heat and smoke build up. The heat and smoke generated can be forced up through any opening such as a door into a stairway. This means that fire-fighting in under-ventilated compartments must be approached with caution before opening the door to the basement storey.

There is also a risk that disoriented occupants could continue their escape to the basement storey instead of escaping through the ground storey.

In order to minimise these risks, a wall or screen (including a self-closing fire door) with a medium fire resistance duration should be provided between the ground storey of the protected zone and the basement storey.

2.9.35 Construction of escape stairs

In buildings of more than 1 storey where the means of escape is via an escape stair, this will also be the route from which the fire and rescue services will fight the fire and effect rescue. The possibility that the escape stair may be affected by fire breaking out or being deliberately set in the stairway has to be considered. Consequently the escape stair should be provided with additional protection.

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Therefore, every part of an escape stair (including landings) and the floor of a protected zone or protected lobby, should be constructed of non-combustible material. However this does not apply to:

•an escape stair in shared residential accommodation

•any handrail, balustrade or protective barrier on an escape stair

•an escape stair which connects 2 or more levels within a single-storey where the difference in height between the highest and lowest level is not more than 1.8m

•an escape stair from a gallery, catwalk or openwork floor constructed in accordance with the guidance in clause 2.9.25

•a floor finish (e.g. laminate flooring) applied to the escape stair (including landings) or to the floor of a protected zone or protected lobby.

2.9.36 External walls adjacent to protected zones

If a protected zone has an external wall that projects beyond the face of a building or is set back in a recess, the protected zone may be vulnerable to fire following the break out of fire through an adjacent window, door or other opening. Radiated heat or flames from the fire may impede occupants using the protected zone to escape.

Therefore where any part of a protected zone is not more than 2m from, and makes an angle of not more than 135° with any part of an external wall of another part of the building, the escape stair should be protected against fire for a distance of 2m, by construction with a:

•short fire resistance duration where every storey in the building is at a height of not more than 7.5m above the ground, or

•medium fire resistance duration where any storey is at a height of more than 7.5m.

The designer can choose which wall should be fire resisting and may include fire resisting facades or other fixed glazing, or any other opening protected against fire. However it is not sufficient to use the final exit door as a barrier between the occupants escaping and the fire. In such cases the external wall adjoining the protected zone at the final exit should be protected against fire as described above.

2.9.37 External routes of escape

Escape routes will normally lead to the final exit door of the building, which leads to a safe place in the outside air from which occupants can freely disperse. An exit can also lead to an external escape stair, a flat roof or access deck giving access to a place of safety.

Protection of external route of escape - in some cases it may not be possible to freely disperse away from the building (e.g. where the final exit door discharges to an enclosed outdoor space). In such cases, where there is only 1 route of escape, the external wall of the building within 2m of the route of escape should have a short fire resistance duration for integrity up to 1.1m above the adjoining ground. This does not apply to sub-floor vents.

An external escape stair is an unenclosed escape stair, which is open to the external air and provides occupants with an escape route, which leads to a place of safety. They present additional hazards to occupants evacuating a building in the event of fire. This is because the escape stair will be exposed to the possible effects of inclement weather and occupants who are unfamiliar with the escape routes can feel less confident using an unenclosed stair high above the ground.

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Therefore, an external escape stair should only serve a building where:

•the top most storey height is not more than 7.5m, and

•the building or part of the building is not accessible to the general public, and

•in the case of a residential care building or a hospital, the stair is intended to be used by staff only.

In order to protect the occupants from fire and smoke during evacuation, the external escape stair should be protected against the outbreak of fire from within the building. Where the escape stair which has a total rise of more than 1.6m, every part of the external wall including fixed windows or glazing, self-closing fire doors (other than a door opening from the top storey) or any other opening not more than 2m from the escape stair, should have a short fire resistance duration. Fire protection below an escape stair should be extended to the lowest ground level.

An external escape stair with a total rise of not more than 1.6m from which occupants can freely disperse, is considered to be low enough above the ground to present minimal risk to occupants leaving the building and as a result, fire protection need not be provided.

Due to the likely smoke dissipation to atmosphere; service openings including ventilation ducts not more than 2m from the escape stair may be protected by heat activated sealing devices or systems.

Escape across flat roofs and access decks can be hazardous because the surface can be exposed to adverse weather conditions and in the case of flat roofs, may also have obstructions or no edge protection. Therefore, escape routes over flat roofs should only be used where the building or part of the building is inaccessible to the general public and there is more than 1 escape route from the room or storey leading to the flat roof.

In order to protect occupants from fire, a flat roof or an access deck forming part of an escape route should have medium fire resistance duration for the width of the escape route and for a further 3m on either side of the escape route. Every wall not more than 2m from either side of the escape route, should have a short fire resistance duration up to a height of at least 1.1m measured from the level of the escape route.

In addition, there should be no exhausts of any kind less than 2m from the escape route unless protected by heat activated sealing devices or systems (see clause 2.1.14). A wall or protective barrier at least 1.1m high may be necessary on each side of the escape route or along the edge of the access deck when the escape route is across a flat roof or access deck (see Section 4 Safety).

2.9.38 Final exits

The final exit to a place of safety at ground level, should present as little restriction as possible to occupants using wheelchairs or having other disabilities. Final exits should therefore be provided with:

•a level platt except for any nominal slope for drainage having an area of at least 1.2m x 1.2m, and

•a threshold that does not form a trip hazard and will permit unassisted egress to occupants in a wheelchair (see Section 4 Safety).

When altering existing buildings, it may not always be reasonably practicable to achieve the above recommendations.

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Mandatory Standard

Standard 2.10

Every building must be designed and constructed in such a way that in the event of an outbreak of fire within the building, illumination is provided to assist in escape.

2.10.0 Introduction

Escape routes should be illuminated to aid the safe evacuation of a building in an emergency.

Emergency lighting and exit signage may be necessary under the Fire Safety (Scotland) Regulations 2006 (see clause 2.0.8).

Reference should be made to Part 1 of the Cinematography (Safety) (Scotland) Regulations 1955 for buildings such as cinemas where there are specific requirements for lighting.

Due to the special fire precautions within residential care buildings, hospitals and enclosed shopping centres, additional guidance is grouped in the annexes. The intention is to help designers and verifiers find the information they require quickly when designing or vetting such buildings. However it is important to remember that the guidance in the annexes is in addition and supplementary to the guidance to Standard 2.1 to 2.15. For additional guidance on:

•residential care buildings, see annex 2.A

•hospitals, see annex 2.B

•enclosed shopping centres, see annex 2.C.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirement of this standard (regulation 12, schedule 6).

2.10.1 Escape route lighting

Escape route lighting utilises the artificial lighting within the building, but should be supplied by a fire protected circuit.

Every part of an escape route should have artificial lighting supplied by a protected circuit that provides a level of illumination not less than that recommended for emergency lighting. Where artificial lighting serves a protected zone, it should be via a protected circuit separate from that supplying any other part of the escape route.

Artificial lighting supplied by a protected circuit need not be provided if a system of emergency lighting is installed.

2.10.2 Protected circuits

A protected circuit is a circuit originating at the main incoming switch or distribution board, the conductors of which are protected against fire. Regardless of what system is employed, escape routes should be capable of being illuminated when the building is in use. In

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conversions for example, it may be easier to install self-contained emergency luminaires than to install a protected circuit to the existing lighting system.

2.10.3 Emergency lighting

Emergency lighting is lighting designed to come into, or remain in, operation automatically in the event of a local and general power failure. It should be installed in buildings considered to be at higher risk, such as in high rise buildings, buildings with basements or in rooms where the number of people is likely to exceed 60.

Emergency lighting should be installed in buildings or parts of a building considered to be at higher risk such as:

a.in a protected zone and an unprotected zone in a building with any storey at a height of more than 18m

b.in a room with an occupancy capacity of more than 60, or in the case of an inner room, the combined occupancy capacity of the inner room plus the adjoining room (and any protected zone or unprotected zone serving these rooms) is more than 60

c.in an underground car park including any protected zone or unprotected zone serving it where less than 30% of the perimeter of the car park is open to the external air

d.in a protected zone or unprotected zone serving a basement storey

e.in a place of special fire risk (other than one requiring access only for the purposes of maintenance) and any protected zone or unprotected zone serving it

f.in a protected zone or unprotected zone serving a storey which has at least 2 storey exits in the following buildings:

•entertainment, assembly, factory, shop, multi-storey storage (Class 1), single-storey storage (Class 1) with a floor area more than 500m²

•a protected zone or unprotected zone serving a storey in a multi-storey non- residential school

•a protected zone or unprotected zone serving any storey in an open sided car park.

Emergency lighting in places of entertainment such as, cinemas, bingo halls, ballrooms, dance halls and bowling alleys, should be in accordance with BS 5266: Part 1: 2016.

Emergency lighting in any other building should be in accordance with BS 5266: Part 1: 2016 as read in association with BS EN 1838: 2013.

In the case of a building with a smoke and heat exhaust ventilation system, the emergency lighting should be sited below the smoke curtains or installed so that it is not rendered ineffective by smoke filled reservoirs.

2.11 Communication

Mandatory Standard

Standard 2.11

Every building must be designed and constructed in such a way that in the event of an outbreak of fire within the building, the occupants are alerted to the outbreak of fire.

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It is important that any outbreak of fire in premises is detected at an early stage in order that the occupants once alerted can commence evacuation of the premises as soon as possible. There should also be a means so that anyone in the building who discovers a fire, can alert others to the existence of the fire and this should include arrangements for calling the fire and rescue service. The benefit of early warning of a fire will increase the probability of the safe evacuation of the building and will assist owners and occupiers of buildings in formulating their fire safety policy and emergency fire action plan.

Risk assessment fire warning - in small single storey non-residential buildings the means of raising the alarm could be quite simple, e.g. where a shouted warning "FIRE" by the person discovering the fire may be all that is needed. In more complex buildings, a sophisticated fire detection and fire alarm system may be needed.

False alarms - around 97% of all automatic calls received by the fire and rescue service result in unnecessary attendance due to false alarms. This is normally attributed to poor, design, installation or maintenance of automatic fire detection and alarm systems. Guidance on how to assess the risks and reduce false alarms is provided in BS 5839: Part

1:2017.

Special fire precautions are necessary within residential care buildings, hospitals and enclosed shopping centres and additional guidance is provided in the annexes. The intention is to help designers and verifiers find the information they require quickly when designing or vetting such buildings. It is important to remember that the guidance in the annexes is in addition and supplementary to the guidance to Standard 2.1 to 2.15. For additional guidance on:

•residential care buildings, see annex 2.A

•hospitals, see annex 2.B

•enclosed shopping centres, see annex 2.C.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirement of this standard (regulation 12, schedule 6).

2.11.1 Evacuation methods

Evacuation methods affect the category of fire detection and fire alarm system that should be installed in a particular building. The type of occupancy and means of escape strategy should be determined at building design stage. For example evacuation may be:

•simultaneous, where all occupants evacuate the building at the same time

•phased, where some occupants evacuate parts of the building before others, or

•progressive horizontal evacuation, where occupants leave the compartment of fire origin to adjacent compartments leading to a storey exit.

Where the design of the means of escape is based on simultaneous evacuation of all occupants, then operation of a manual call point or fire detector should give an almost instantaneous warning from all the fire alarm sounders. However where the means of escape is based on phased evacuation, then a staged alarm system is appropriate. This enables two or more stages of alarm to be given within a particular area (e.g. alert or evacuate signals).

Building uses incorporating design for phased evacuation are often a fire engineered solution which will include the fire alarm specification. Dependant on the determined use at design stage, a category L1 to L5 with or without voice alarm should be installed.

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The factors that should be considered when assessing what category of fire alarm or automatic fire detection system is to be provided, will vary widely from one premises to another therefore the type of system will need to be considered on a case by case basis.

2.11.2 Assessment of the determined use

An assessment of the determined use should be carried out at the design stage, taking into account the building evacuation factors in order to specify the appropriate alarm category for the circumstances concerned. The significance of various evacuation factors will depend on use and occupancy. These factors are:

•whether occupants are awake and alert or asleep

•are they familiar or not with the building

•the complexity of the building

•the number of occupants

•the type of activity, and

•evacuation method.

In any building, some of the occupants may have impaired sensory, cognitive and/or mobility impairments which could create difficulties in perceiving or responding to a fire or in evacuating the building.

Compensatory features - buildings in which other fire precautions, such as means of escape, depart from the Technical Handbook guidance should have in place fire alarms systems to compensate for such departures. Category, L1, L2, L3, L4, or L5 systems should therefore be installed in the building.

2.11.3 Categories of fire detection and fire alarm system

Fire detection and fire alarm system is a term used in this handbook to describe any type of automatic sensor network and associated control and indicating equipment. Sensors may be sensitive to smoke, heat, gaseous combustion products or radiation. Normally the control and indicating equipment operates a fire alarm system and it may perform other signalling or control functions as well. Automatic sprinkler systems may also be used to operate a fire alarm system.

At the design stage it is important to take into account the building evacuation factors, in order to specify the alarm category. Life safety fire alarm systems installed in a building will be one or more of the following categories.

Category L systems are automatic fire alarm systems installed for the protection of life, incorporating detectors, sounders and manual call points installed in the building. Category L fire alarm systems are sub-divided from the most stringent L1 to the least stringent requirement L5, depending on the detector coverage in the building:

•L1 detectors are installed throughout the building; the objective of a category L1 system is to offer the earliest possible warning of fire, so as to achieve the longest available time to escape

•L2 detectors are installed in the building so as to give warning before escape routes are impassable owing to the presence of fire, smoke or toxic gases; but with enhanced coverage in specified areas of the building

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•L3 detectors are installed so as to give a warning of fire at an early enough stage to enable all occupants, other than possibly those in the room of fire origin, to escape safely, before the escape routes are impassable owing to the presence of fire, smoke or toxic gases

•L4 detectors are installed in those parts of the escape routes comprising circulation areas and circulation spaces, such as corridors and stairways

•L5 detectors, sounders are installed in specified locations where the designed is to satisfy a specific fire safety objective (other than that of a category L1, L2, L3 or L4 system).

Categories L1 to L5 should be installed in accordance with BS 5839: Part 1: 2017 which specifies various categories of life safety fire alarm systems.

Category M is a standalone manual fire alarm system that includes manual call points and sounders at specific locations in the building. Automatic detection is not part of the system. Nevertheless category M systems should be installed in conjunction with L1, L2, L3, L4, L5 and voice alarm systems.

BS EN 54: Part 11: 2001 covers two types of call points. Type A (direct operation) in which the change to the alarm condition is automatic (i.e. without the need for further manual action) when the frangible element is broken or displaced and Type B (indirect operation) in which the change to the alarm condition requires a separate manual operation of the operating element by the user after the frangible element is broken or displaced.

Manual call points as specified in BS EN 54: Part 11: 2001 (Type A) should be installed in buildings and sited in accordance with BS 5839: Part 1: 2017.

Voice alarms - in complex and multi use buildings the installation of a voice alarm should be considered. For example, where a building is designed for phased evacuation or where occupants might not respond quickly to a fire warning, or where occupants are unfamiliar with the fire warning arrangements. Voice alarms systems may be used to alert staff or give a coded message explicit to those having responsibility for taking action in a fire. They can form part of a public address system and give both an audible signal and verbal instructions (which may be pre-recorded) in the event of fire. A voice alarm system should be installed to comply with BS 5839: Part 8: 2013.

The fire warning signal should be distinctive in sound from other sounds which may be in general use and be accompanied by clear verbal instructions.

In some circumstances visual alarm signals should be used to either supplement or replace the audible alarm, such as where hearing protection is likely to be used or in situations where occupants have a hearing impairment. Buildings such as hospitals and residential care buildings for example may incorporate a combination of audible, visual and voice alarm in the overall system.

2.11.4 Residential care buildings

A residential care building should have a communication system designed and installed in accordance with the guidance set out in annex 2.A. This is to give occupants and staff the earliest possible warning of an outbreak of fire and allow time for assisting occupants in an emergency to evacuate the building or for horizontal progressive evacuation initially to an adjacent compartment which leads to a compartment exit.

2.11.5 Hospitals

A hospital should have a communication system designed and installed in accordance with the guidance set out in annex 2.B. This is to give occupants and staff the earliest possible

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warning of an outbreak of fire and allow time for assisting occupants in an emergency to evacuate the building or for horizontal progressive evacuation initially to an adjacent sub- compartment which leads to a compartment exit.

2.11.6 Shared residential accommodation

Shared residential accommodation is designed to provide sleeping accommodation for not more than 10 persons, entered from open air at ground level and having no sleeping accommodation at a storey height of more than 7.5m. At least a category LD2 (Grade D) should be installed.

2.11.7 Residential buildings (other than residential care buildings and hospitals)

The threat posed by a fire in Residential buildings such as hotels and boarding houses in which occupants may be asleep, is much greater than that in buildings where the occupants are normally awake and alert. Guests may not be aware that their lives are at risk and are also likely to be unfamiliar with their accommodation or escape routes.

A category L2 system is likely to be appropriate for the majority of sleeping accommodation premises. However it is important that the choice of system category is based on a risk assessment of the particular circumstances.

Early warning of fire significantly increases the degree of safety provided to occupants. In order to minimise false alarms, a variation from the category L1 system may be justified regards the siting of smoke or carbon monoxide detectors in bedroom areas. Detectors are typically installed in most other rooms and few if any areas should be left unprotected and a category L1 or L2 system should be installed.

2.11.8 Entertainment buildings and assembly buildings

The occupants will be alert but could be unfamiliar with the building; nevertheless they should be able to respond to an outbreak of fire in their immediate area. Certain events, such as some pop concerts, may attract large numbers of young, excitable persons and will require a greater degree of control and stewarding than for other events which, despite attracting similar audience numbers, will have an entirely different behaviour profile, such as a play performed in a large theatre.

A category L1, L2, L3, or M system, should be installed in the building. The category will be dependant on the use of the building, for example whether it is a cinema, restaurant or nightclub, an assessment should be carried out at the design stage to determine the appropriate category. The following is a guide only.

Where there are:

•more than 300 occupants then a category L1 system should be installed

•no more than 300 occupants but more than 100 then at least a category L2, system should be installed

•no more than 100 occupants but more than 60 then at least a category L3 system should be installed, and

•no more than 60 then at least a category M system should be installed.

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In shops, the occupants will be alert but could be unfamiliar with the premises however they should be able to respond to an outbreak of fire in their immediate area. In department stores with restaurants or cafeteria a phased evacuation can be used where fire safety measures are provided to facilitate this strategy. A category M, L3 or L4 system should be installed, in shops where there are:

•more than 300 occupants then a category L3 system should be installed

•where the building is in different occupation then a category L3 system should be installed

•not more than 300 occupants but more than 100 then a category L4 system should be installed, and

•not more than 100 occupants then a category M system should be installed.

In offices, the occupants will be alert and familiar with the building and are unlikely to be so engaged with the task at hand that they initially fail to perceive or respond to an outbreak of fire in their immediate area. In these circumstances, a manually operated category M system that can be heard throughout the building when operated from a manual call point may be all that is required.

2.11.10 Educational building

Many educational buildings are also a community resource and serve a variety of functions. It is therefore important that the choice of system category is based on risk assessment of the particular circumstances. An example would be where a country school could consist of one large classroom with 14 pupils and a teacher, where the warning is understood, and can be heard throughout the building. More complex educational buildings, may contain different uses such as large assembly areas, auditoriums, or administration centres. In such cases, the guidance under the relevant building types should also be followed. In educational buildings with more than 60 occupants therefore, at least a category M, L3, L4 or L5 system should be installed dependant on assessment at the design stage.

2.11.11 Factory buildings and storage buildings

In factory buildings (class 1), factory (class 2), storage buildings (class 1) and storage buildings (class 2) the occupants will be alert and will be familiar with the building, also the numbers of persons in the building will normally be low but can vary for example a large compartment with production lines such as clothes manufacturing. Due to the varied nature of use, some buildings may contain hazardous or dangerous materials or processes, with the potential for fire or explosion, posing an additional risk to persons, on or in the immediate vicinity of the building. Such factors should be part of the fire risk assessment to ensure that fire safety measures are provided to safeguard occupants who are so engaged with the task at hand that they may initially fail to perceive or respond to an outbreak of fire in their immediate area.

Normally a category M system should be installed, however occupants could work alone in remote areas of the building and this should be considered when determining the category of system.

Therefore dependant on assessment at design stage a category M, L1, L2, L3, L4, or L5 should be installed.

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An enclosed shopping centre should have a communication system designed and installed in accordance with the guidance set out in annex 2.C.

2.11.13 Transportation Terminals

These buildings may be small single-storey or large complex buildings which include mixed use occupancy such as airports, where the category of alarm system will normally form part of a fire engineering solution. Excluding large complex buildings and dependant on risk assessment at design stage, a category M, L4 or L5 system should be installed.

2.11.14 Other non-residential buildings

In small single-storey buildings where the occupant number is not more than 10 and the floor area is such that everyone can see each other, a shouted warning "FIRE" by the person discovering the fire could be all that is needed. In assessing the situation, it must be determined that the warning can be heard and understood throughout the building, or compartment, including those in remote locations such as toilets.

2.12 Fire and rescue service access

Mandatory Standard

Standard 2.12

Every building must be accessible to fire and rescue service.

2.12.0 Introduction

Vehicle access to the exterior of a building is needed to enable high reach appliances, such as turntable ladders and hydraulic platforms, to be used, and to enable pumping appliances to supply water and equipment for fire-fighting and rescue activities. The access arrangements increase with building size and height.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirements of this standard in so far as is reasonably practicable, and in no case be worse than before the conversion (regulation 12, schedule 6).

2.12.1 Vehicle access provision

Access from a public road should be provided to assist fire and rescue personnel in their rescue and fire-fighting operations. Whilst the access will depend to some extent on the vehicles and equipment used, assistance may be provided from adjoining fire and rescue services when the need arises. For this reason, the more demanding guidance for high reach appliances may be recommended by the fire and rescue service. This may have a significant impact on planning and a feasibility study may be appropriate. Consultation with the fire and rescue service at the earliest opportunity is strongly recommended.

Vehicle access should be provided to at least one elevation of all buildings to assist in fire- fighting operations. The vehicle access route should be provided to the elevation or/and rescue elevations where the principal entrance, or entrances, are located.

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Vehicle access is recommended to other elevations of a building where:

•the building is a hospital, or

•the area of any compartment in a non-domestic building is more than 900m², or

•the building footprint has a perimeter more than 150m.

However vehicle access routes to more than one elevation may not always be possible due to the constraints of the site, and pedestrian access for fire and rescue service personnel, as described in clause 2.12.4, may be sufficient.

To assist fire and rescue service personnel to connect a short length of hose between the pumping appliance and dry/wet riser inlets (see guidance to Standard 2.14) quickly and efficiently, parking spaces should be provided at a distance not more than 18m from riser inlets.

2.12.2 Vehicle access routes

Access routes to buildings for fire and rescue service vehicles or personnel should not be assessed in isolation and the proposed vehicle access routes will in effect, be dictated by need for water hydrants and fire mains (see clause 2.14.7).

Dead end route - fire and rescue service vehicles should not have to reverse more than 20m from the end of an access road. Where any dead-end route is more than 20m long, turning facilities should be provided. This can be a turning circle or a hammerhead designed on the basis of the diagram and table below:

Figure 2.17 Turning facilities

Table 2.15 Access route for fire and rescue service vehicles

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Additional information:

1.Where, in consultation with the fire and rescue service, access is needed for pumping appliances only, the smaller dimensions may be used.

2.12.3 Operating spaces for high reach appliances

Following consultation with the fire and rescue service, if it is recommended that an operating space, or spaces, for a high reach appliance should be provided, the operating space(s) should:

•have a ground loading capacity of not less than 8.3kg/m², and

•be level or not have a gradient more than 1 in 12.

The operating space shown in the diagram below is suitable for either a hydraulic platform or turntable ladder.

Where a building has obstructions such as balconies or other projections, the building line should be taken to be the outer edge of the balconies or other projections.

Figure 2.18 Minimum dimensions for operating space for high reach appliances

2.12.4 Access for fire and rescue service personnel

It is common practice for fire and rescue service personnel to enter a building through the normal entrances and fight the fire head on. This is termed ‘offensive fire-fighting’.

In order to allow unobstructed access to a building for fire and rescue service personnel, a paved (or equivalent) footpath at least 900mm wide (see also Section 4 Safety) should be provided to the principal entrance, or entrances, of a building. In addition, where vehicle access is not possible to within 18m of the dry riser inlets (see clause 2.12.1) a footpath should also be provided to the riser inlets.

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Every elevation which is provided with vehicle or pedestrian access for fire and rescue service personnel, should have a door giving access to the interior of the building. Inward opening doors are preferable because this allows easier forced entry by fire and rescue service personnel should the need arise. However an outward opening final exit door or emergency door (see clause 2.9.16) should also be considered as providing suitable access.

2.13 Fire and rescue service water supply

Mandatory Standard

Standard 2.13

Every building must be provided with a water supply for use by the fire and rescue service.

2.13.0 Introduction

Fire-fighting operations depend on a sufficient supply of water in order to control fire growth and assist in effective rescue operations.

The fire and rescue service should be provided with a water supply to assist with their fire- fighting and rescue operations. This is normally provided from public water mains through fire hydrants or alternative water supplies such as tanks or reservoirs may be provided.

In some cases, the existing water supply may be sufficient and there is no need to provide additional water supplies. Therefore, it is important to consult the fire and rescue service and water authority early in the design process to establish what water supply, if any, should be provided in order to carry out their statutory duties under the Fire (Scotland) Act 2005 as amended.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirement of this standard (regulation 12, schedule 6).

2.13.1 Water supply

Every non-domestic building should, be provided with a water supply to assist fire fighting and rescue operations from:

•a public water supply, or

•an alternative water supply.

2.13.2 Public water supply

An existing hydrant may be used to supply water for fire-fighting where:

•the building has a footprint of not more than 280m², and

•the hydrant is located not more than 100m away from the building, and

•no compartment has an area more than 280m², and

•top storey not more than 7.5m above access level.

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Positioning of hydrants - a building with a footprint or compartment area of more than 280m² should be provided with at least 1 water hydrant. However where no piped water supply is available, an alternative source of supply should be provided (clause 2.13.3).

The water hydrants should be positioned externally, for each building or where common to more than one building:

•not more than 60m from at least one normal entrance to the building, and

•distributed around the building so that every external elevation of the building is within 60m from a hydrant, and

•so that hydrants are at least 6m away from the building, and

•located adjacent to a parking space for a pumping appliance, and

•where a parking space is provided for a fire appliance in accordance with clause 2.14.7 (fire mains), the water hydrant should be located adjacent to that parking space, and

•so as to be accessible for use at all times, and

•so that there is a clear route for the fire hose between the hydrant and the building, and

•the hydrants are constructed in accordance with BS 750: 2006.

A fire hydrant should be clearly indicated by a plate, affixed nearby in a conspicuous position, in accordance with BS 3251:1976.

Performance criteria - a hydrant should be connected to a water service pipe capable of delivering water at a flow rate of at least 1500 litres per minute, provided by a water main vested in a public water authority or a supply provided under the Fire (Scotland) Act 2005 as amended. Alternative arrangements, including private supplies, should be agreed with the verifier and water authority, where relevant.

Whilst it is desirable to achieve 1500 litres per minute flow rate, it is accepted that the flow rates in the water mains may not achieve this. Localised areas throughout Scotland may not be supplied by mains water or, where mains water is available, the pressure and flow rates in the main may not be sufficient for fire-fighting operations. Skilled pump operators can regulate the water supplies to the fire-fighters and take care not to overdraw the mains especially where the mains pressure and flow rates are poor.

Portable pumps - in some cases, where there are insufficient water hydrants distributed around existing buildings, it is normal practice to deploy portable pumps to relay water supplies to where the water is needed. Whilst this method of water distribution is quite common, it should be avoided for new developments because of the time delay in supplying water to the fire-fighters.

2.13.3 Alternative water supply

Where no piped water supply is available, or there is insufficient pressure and flow in the water main, or an alternative arrangement is proposed, the alternative source of supply should be provided in accordance with the following recommendations:

•a charged static water tank of at least 45,000 litres capacity, or

•a spring, river, canal, loch or pond capable of providing or storing at least 45,000 litres of water at all times of the year, to which access, space and a hard standing are available for a pumping appliance (see clause 2.12.2), or

•any other means of providing a water supply for fire-fighting operations considered appropriate by the fire and rescue service.

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Mandatory Standard

Standard 2.14

Every building must be designed and constructed in such a way that facilities are provided to assist fire-fighting or rescue operations.

2.14.0 Introduction

Facilities within a building are provided to assist the fire and rescue service carry out their statutory duties as efficiently and safely as possible. Fire and rescue service personnel are trained to enter buildings following the outbreak of fire to assist with any evacuation of the building occupants, effect rescues of any casualties and to fight fires. Fire-fighters operational duties are made on a statutory basis in the Fire (Scotland) Act 2005 as amended, which states:

“Each relevant authority shall make provision for the purpose of –

1.extinguishing fires in its area

2.protecting life and property in the event of fires in its area.”

The extent of fire development will vary with each incident and in any situation, the fire and rescue service will assess the need to evacuate the entire building whilst the fire is brought under control. Sometimes, the fire can develop to such an extent that additional fire-fighting teams may need to be summoned from other fire stations or fire authorities.

Fire-fighters will normally enter a building through the main entrance and attempt to attack the fire. This is termed ‘offensive fire-fighting’ and is normal practice regardless of whether people are in the building or not. When conditions within the building become too hazardous for fire-fighters to remain, they will normally retreat a safe distance away from the building and implement ‘defensive’ fire-fighting tactics to control the spread of fire. In cases where a large fire develops, numerous fire-fighting teams may be involved using a combination of offensive and defensive tactics until the fire is brought under control and extinguished.

Whilst fire-fighters are professionally trained to deal with all types of fire condition, the fire and rescue service facilities within a building are important to reduce fire attack time which in turn, could save lives, limit the fire damage to property and improve fire-fighter safety.

Due to the special fire precautions within residential care buildings, hospitals and enclosed shopping centres, additional guidance is grouped in the Annexes. The intention is to help designers and verifiers find the information they require quickly when designing or vetting such buildings. However it is important to remember that the guidance in the annexes is in addition and supplementary to the guidance to Standard 2.1 to 2.15. For additional guidance on:

•residential care buildings, see annex 2.A

•hospitals, see annex 2.B, and

•enclosed shopping centres, see annex 2.C.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirement of this standard (regulation 12, schedule 6).

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Fire and rescue service facilities may need to be provided in a building to assist with any evacuation of the building occupants, effect rescues of any casualties and to fight fires. The time taken for fire and rescue service intervention is dependent on a number of variables. The time to contact the emergency services, the location of the building in relation to the fire station and the height of the floor of fire origin above or below the fire and rescue service access level.

Fires in tall buildings or in basement storeys may present additional risks to fire and rescue service personnel. Fire and smoke can suddenly change direction and intensity due to a number of factors which might induce reverse air flows. For example, the wind direction and velocity (which increases with height) could have a significant impact when fire-fighters open the door to the room or storey of fire origin. Similarly, limited ventilation available in a basement storey can lead to heat and smoke build up that is released through the opening the fire-fighters are using as an entry point.

It is important that the facilities to assist the fire and rescue services take account of the building design. The Building Disaster Assessment Group carried out extensive research on behalf of the UK Government to assess the interaction between building design and the operational response of fire and rescue services. The subjects covered by the research included:

•physiological performance criteria for fire-fighting

•fire-fighting in under-ventilated compartments, and

•fire-fighting media in high-rise buildings.

The research is available on the UK Government website http://www.communities.gov.uk/ fire/.

2.14.2 Number and type of facilities

The further fire-fighters need to travel to reach the seat of the fire above or below ground, the greater the risk. Therefore, the number and type of facilities provided should be based on the height of the topmost storey above the fire and rescue service access level, the depth of any basement storeys below the access level and the distance from any fire mains outlets (see clause 2.14.7).

The type of facilities that are necessary may include:

•fire-fighting stairs

•fire-fighting lifts

•fire-fighting lobbies, and

•heat and smoke control (e.g. natural or mechanical ventilation).

Height of topmost storey - building design should complement fire-fighting and rescue capability. The 7.5m storey height above the ground is historically linked to the height at which fire and rescue service personnel can rescue occupants using the standard 13.5m portable ladder. Whilst this practice is no longer common, for health and safety reasons, fire-fighters continue to carry out external rescues as a last resort and building design should recognise this.

The 18m storey height above the ground is also historically linked with the reach capability of fire and rescue service equipment such as wheeled escape ladders (now obsolete). The

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general intent is that buildings with a storey at a height of more than 18m above the access level, cannot be easily reached by fire and rescue service equipment and personnel. Therefore, at least 1 fire-fighting shaft (fire-fighting stair, fire-fighting lobby, fire mains and in some cases a fire-fighting lift) is provided within the building to allow equipment and personnel to be deployed as quickly as possible.

In addition, fire-fighters cannot apply water jets from fire hoses onto external walls high above the ground because of the limited reach capability. The guidance throughout this handbook including Standard 2.7, spread on external walls, recognises this limitation.

The fire and rescue service facilities recommended in the table should be applied on every storey, however the lowest basement storey sets the level of facilities recommended throughout the basement storeys only. The depth of the lowest basement storey is measured from the fire and rescue service access level to the upper surface of the lowest basement storey. The height of the topmost storey of a building is measured from the fire and rescue service access level to the upper surface of the topmost storey.

Table 2.16 Fire and Rescue Service facilities

Additional information:

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1.The access level is the level at which the fire and rescue service enter the building to commence fire-fighting and rescue operations.

2.Ventilation to stairs includes both escape stairs and fire-fighting stairs (see clause 2.14.6).

3.For open side car parks there is no need for fire-fighting lobbies or dry fire mains.

Figure 2.19 Typical upper floor - office building

2.14.3 Fire-fighting stairs

At least 1 fire-fighting stair should be provided to assist fire-fighters to access the fire and if necessary escape from the fire in relative safety. The fire-fighting stair should be at least 1.0m wide measured between handrails to provide fire and rescue service personnel sufficient room to carry fire-fighting and rescue equipment.

A fire-fighting stair should be contained within a protected zone. The enclosing structure of the protected zone should have at least a medium fire resistance duration and should have a long fire resistance duration where it serves:

•a basement storey at a depth of more than 10m below the fire and rescue service access level

•a shop, factory, storage building or an open sided car park where the area of any storey is more than 900m², or

•any building where the topmost storey is more than 18m above the fire and rescue service access level.

However where the elements of structure in a building have a medium fire resistance duration, the protected zone need only have a medium fire resistance duration.

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A self-closing fire door in the enclosing structure of a protected zone should have at least a medium fire resistance duration. In some cases an escape stair can be used as a fire- fighting stair. For example, in single stair buildings.

Figure 2.20 Fire and Rescue Service facilities

2.14.4 Fire-fighting lifts

A fire-fighting lift allows fire and rescue service personnel to transport equipment to a floor of their choice as quickly as possible. The lift also allows fire-fighters to access several floors quickly to assess the situation and to rescue any casualties.

The lift installation includes the lift car itself, the lift well and the lift machinery space, together with the lift control system and the lift communication system. The lift control and communication system should be capable of being used under the direct control of the fire and rescue services. The lift installation should conform to BS EN 81: Part 72: 2015 and BS EN 81: Part 20: 2014 or BS EN 81: Part 50: 2014 depending on the type of lift.

A fire-fighting lift should be located within a protected zone and constructed within its own compartment having at least a medium fire resistance duration. The lift landing doors need only achieve a short fire resistance duration.

The lift should only be entered from:

•a fire-fighting lobby with not more than 1 door to the room or storey it serves, or

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•an access deck.