The Merged Approved Documents

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The Merged Approved Documents

For use in England

October 2024 compilation of individual approved documents

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This document of the Approved Documents now includes:

•Approved Document G – Sanitation, hot water safety and water efficiency, 2015 edition incorporating 2016 and 2024 amendments

•Approved Document M Volume 2 – Access to and use of buildings, 2015 edition incorporating 2020 and 2024 amendments

•Approved Document T – Toilet accommodation, 2024 edition

These approved documents took effect on the dates stated in the individual documents, for use in England.

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How to use the Merged Approved Documents

This document combines the approved documents into a single PDF. Each approved document is self-contained and has its own introduction. Each introduction relates only to the corresponding approved document. Each introduction also contains information on when the document’s guidance came into effect (or will come into effect). It is important to check that the version of each approved document you are using remains current and is the correct version for your project. Please refer to the Ministry of Housing, Communities and Local Government’s website to check, and confirm with your building control body if in doubt.

Key features

The Merged Approved Documents enable the user to:

•undertake a word search across all of the approved documents

•cut and paste text and diagrams into other documents

•add notes to a saved copy

•use an index to access individual sections of the guidance

Forthcoming changes

Please check the Ministry of Housing, Communities and Local Government’s website to ensure that each approved document you are using is current for your project. This is particularly important in relation to Approved Document B as this has been subject to frequent update. It is intended that the Merged Approved Documents will be updated whenever an amendment or revision to an approved document is made.

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Materials and workmanship

Approved Document 7

Regulation 7

2013 edition incorporating 2018 amendments – for use in England*

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This approved document supports regulation 7: Materials and workmanship. It takes effect on 1 July 2013 and is for use in England*. The 1999 edition will continue to apply to work started before 1 July 2013, or to work subject to a building notice, full plans application or initial notice submitted before 1 July 2013.

There is no change to Regulation 7. The main changes in this approved document are that:

•The document has been updated to reflect the full implementation of European Regulation 305/2011/EU-CPR covering construction products, referred to as the Construction Products Regulation, from 1 July 2013. This Regulation requires that products covered by a harmonised European product standard or conforming to a European Technical Assessment should normally have CE marking.

•Reference to the environmental impact of building work has been deleted.

•Guidance on resistance to moisture and substances in the subsoil has been deleted; this is now included in Approved Document C.

•Examples of materials susceptible to changes in their properties have been deleted. (In the case of intumescent coatings, durability testing is now an established element of testing of such products.)

•A new-style format has been used.

Main changes made by the 2018 amendments

Paragraph 1.28 has been inserted in line with the introduction of regulation 7(2).

*This approved document gives guidance for compliance with the Building Regulations for building work carried out in England. It also applies to building work carried out on excepted energy buildings in Wales as defined in the Welsh Ministers (Transfer of Functions) (No. 2) Order 2009.

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What is an approved document?

The Secretary of State has approved a series of documents that give practical guidance about how to meet the requirements of the Building Regulations 2010 for England. Approved documents give guidance on each of the technical parts of the regulations and on regulation 7 (see the back of this document).

Approved documents set out what, in ordinary circumstances, may be accepted as reasonable provision for compliance with the relevant requirements of the Building Regulations to which they refer. If you follow the guidance in an approved document, there will be a presumption of compliance with the requirements covered by the guidance. However, compliance is not guaranteed; for example, ‘normal’ guidance may not apply if the particular case is unusual in some way.

Note that there may be other ways to comply with the requirements – there is no obligation to adopt any particular solution contained in an approved document. If you prefer to meet a relevant requirement in some other way than described in an approved document, you should discuss this with the relevant building control body.

In addition to guidance, some approved documents include provisions that must be followed exactly, as required by regulations or where methods of test or calculation have been prescribed by the Secretary of State.

Each approved document relates only to the particular requirements of the Building Regulations that the document addresses. However, building work must also comply with any other applicable requirements of the Building Regulations.

How to use this approved document

This document uses the following conventions.

a.Text against a green background is an extract from the Building Regulations 2010 or the Building (Approved Inspectors etc.) Regulations 2010 (both as amended). These extracts set out the legal requirements of the regulations.

b.Key terms, printed in green, are defined in Appendix A.

c.When this approved document refers to a named standard or other document, the relevant version is listed in Appendix B. However, if the issuing body has revised or updated the listed version of the standard or document, you may use the new version as guidance if it continues to address the relevant requirements of the Building Regulations.

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If you do not understand the technical guidance or other information in this approved document or the additional detailed technical references to which it directs you, you can seek further help through a number of routes, some of which are listed below.

a.The Planning Portal website: www.planningportal.gov.uk.

b.If you are the person undertaking the building work: either from your local authority building control service or from an approved inspector.

c.If you are registered with a competent person scheme: from the scheme operator.

d.If your query is highly technical: from a specialist or an industry technical body for the relevant subject.

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The following is a high level summary of the Building Regulations relevant to most types of building work. Where there is any doubt you should consult the full text of the regulations, available at www.legislation.gov.uk.

Building work

Regulation 3 of the Building Regulations defines ‘building work’. Building work includes:

a.the erection or extension of a building

b.the provision or extension of a controlled service or fitting

c.the material alteration of a building or a controlled service or fitting.

Regulation 4 states that building work should be carried out in such a way that, when work is complete:

a.for new buildings or work on a building that complied with the applicable requirements of the Building Regulations: the building complies with the applicable requirements of the Building Regulations.

b.for work on an existing building that did not comply with the applicable requirements of the Building Regulations:

(i)the work itself must comply with the applicable requirements of the Building Regulations

(ii)the building must be no more unsatisfactory in relation to the requirements than before the work was carried out.

Material change of use

Regulation 5 defines a ‘material change of use’ in which a building or part of a building that was previously used for one purpose will be used for another.

The Building Regulations set out requirements that must be met before a building can be used for a new purpose. To meet the requirements, the building may need to be upgraded in some way.

Energy efficiency requirements

Part 6 of the Building Regulations imposes additional specific requirements for energy efficiency.

If a building is extended or renovated, the energy efficiency of the existing building or part of it may need to be upgraded.

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Most building work and material changes of use must be notified to a building control body unless one of the following applies.

a.It is work that will be self-certified by a registered competent person or certified by a registered third party.

b.It is work exempted from the need to notify by regulation 12(6A) of, or Schedule 4 to, the Building Regulations.

Responsibility for compliance

People who are responsible for building work (e.g. agent, designer, builder or installer) must ensure that the work complies with all applicable requirements of the Building Regulations. The building owner may also be responsible for ensuring that work complies with the Building Regulations. If building work does not comply with the Building Regulations, the building owner may be served with an enforcement notice.

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Summary

0.1This approved document gives guidance on how to comply with regulation 7 of the Building Regulations. It contains the following sections:

Section 1: Materials Section 2: Workmanship.

Continuing control

0.2There are no provisions under the Building Regulations for continuing control over the materials used in building work following completion of the work. However, under section 19 of the Building Act 1984, local authorities may impose conditions with regard to the proposed use of prescribed short-lived materials, even when the plans conform to the regulations. However, no materials are currently prescribed for the purpose of section 19.

Interaction with other legislation

0.3The Construction Products Regulation requires that construction products that are covered by a harmonised European product standard or conform to a European Technical Assessment should normally have CE marking.

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This approved document gives guidance on how to meet regulation 7 of the Building Regulations 2010.

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Performance

In the Secretary of State’s view, you will meet the requirements of regulation 7 if you satisfy both of the following conditions.

a.Materials are of a suitable nature and quality in relation to the purposes and conditions of their use.

b.Workmanship is such that, where relevant, materials are adequately mixed or prepared and applied, used or fixed so as to perform adequately 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

c.backfilling for excavations in connection with building work.

Limitations

Regulation 7 applies to all building work. However, in accordance with regulation 8 and Schedule 1, the standards of materials and workmanship need be no more than are necessary to:

a.for Parts A–D, F–K, N and P (except for paragraphs G2, H2 and J7) of Schedule 1: secure reasonable standards of health or safety for people in or about the building

b.for Part E of Schedule 1: secure reasonable resistance to the passage of sound for the welfare and convenience of people in or about the building

c.for Part L of Schedule 1: conserve fuel and power

d.for Part M of Schedule 1: provide access to buildings and their facilities for people.

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1.1Building work must meet the functional requirements of Schedule 1 to the Building Regulations. Approved documents refer to materials covered by harmonised European product standards, British Standards and other technical specifications. However, there is no obligation to adopt any particular solution contained in an approved document in order to meet functional requirements; the references are not exclusive and other materials may be suitable in the particular circumstances.

Ways of establishing the fitness of materials

1.2You can assess the suitability of a material for use for a specific purpose in a number of ways, as described in paragraphs 1.3 to 1.21.

CE marking under the Construction Products Regulation

1.3Many materials are construction products that have CE marking under the Construction Products Regulation (305/2011/EU-CPR).

The Construction Products Regulation 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.

1.4CE marking includes the reference of the product standard and the 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 the building work.

1.5In 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 the building works.

1.6In the absence of indications to the contrary, the building control body 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 performance.

1.7If the declared performance of a product is suitable for its intended use, the building control body should not prohibit or impede the use of the product.

CE marking under other EU directives and regulations

1.8Products may have CE marking under European legislation such as the Gas Appliances Directive or the Pressure Equipment Directive. 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.

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1.9Some products have CE marking in accordance with both the Construction Products Regulation and other legislation. The CE marking shows that the product complies with the requirements in all relevant EU legislation.

British Standards

1.10Nearly all British Standards for construction products are the British versions of harmonised European standards used for CE marking. The BSI numbering policy is to adopt the CEN numbering, prefaced with BS, e.g. BS EN 197-1:2000.

1.11Some 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.

1.12Some British Standards for products not covered by a European standard will continue to exist.

1.13Where a construction product has been made and assessed in accordance with one or more British Standards referred to in 1.11 and 1.12, this may show whether the product is suitable for its intended use.

Other national and international technical specifications

1.14An international technical specification, including those prepared by ISO, or 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 person who intends to carry out the work should obtain translations of specifications and demonstrate how the material meets the requirements of regulation 7.

Independent certification schemes

1.15There are many independent product certification schemes in the UK and elsewhere that may provide information on the performance of a product. Such schemes certify that a material complies with the requirements of a recognised document and indicates it is suitable for its intended purpose and use. These may be in addition to, but not conflict with, CE marking.

1.16Accreditation of a certification body by a national accreditation body belonging to the European co-operation for 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 the United Kingdom Accreditation Service (UKAS), which belongs to the EA.

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

Tests and calculations

1.17Where there is no relevant harmonised European standard, tests, calculations or other means may be used to demonstrate that the material can perform the function for which it is 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 tests can be relied on.

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1.18Past experience, such as use in an existing building, may show that the material can perform the function for which it is intended.

Sampling

1.19Under regulation 46 of the Building Regulations, local authorities have the power to take samples as necessary to establish whether materials to be used in building work comply with the provisions of the regulations.

1.20Regulation 46 does not apply to any work specified in an initial notice or to any work for which a final certificate has been given by an approved inspector and accepted by the local authority.

1.21Regulation 8 of the Building (Approved Inspectors etc.) Regulations 2010 provides that an approved inspector, having given an initial notice which continues to be in force, may take samples of material as are reasonable to establish within the limits of professional skill and care that regulation 7 of the Building Regulations or any other applicable regulations are complied with.

Short-lived materials

1.22Some 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.

1.23A short-lived material which is 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 people in and around the building.

1.24If a short-lived material is 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.

1.25As noted in paragraph 0.2, local authorities have the power to impose conditions on the use of short-lived materials.

Materials susceptible to changes in their properties

1.26The properties of some materials can change in certain environmental conditions. These changes can affect the performance of the materials over time.

1.27Materials 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, meet both of the following conditions.

a.Residual properties can be estimated at the time of their incorporation in the work.

b.Residual properties are shown to be adequate for the building to perform the function for which it is intended, for the expected life of the building.

Non-combustible materials in external walls of tall buildings

1.28The Building Regulations restrict the use of combustible materials in the external walls of certain buildings over 18m in height. Refer to regulation 7(2) of the Building Regulations and to Approved Document B: volume 2, part B4 for details.

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Ways of establishing the adequacy of workmanship

2.1Examples of ways to establish the adequacy of workmanship are described in paragraphs 2.2 to 2.11.

CE marking

2.2If a material has CE marking, workmanship may be specified in the relevant European Technical Assessment or harmonised product standard.

Standards

2.3Methods of carrying out different types of work are also given in British Standards or other appropriate technical specifications.

Independent certification schemes

2.4Some independent certification schemes specify how workmanship will deliver a declared level of performance. The person carrying out the work should show that the workmanship will provide the appropriate level of protection and performance.

2.5Schemes, including competent person self-certification schemes, that register installers of materials can provide a means of ensuring that work has been carried out by knowledgeable contractors to appropriate standards.

Management systems

2.6The 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

2.7Past experience, such as use in an existing building, may show that workmanship is appropriate for the function for which it is intended.

Tests

2.8Tests can be used to show that workmanship is appropriate.

2.9In the following three instances, the Building Regulations require those carrying out building work to have testing carried out to demonstrate compliance.

a.Sound insulation as described in regulation 41.

b.Air flow rate of mechanical ventilation as described in regulation 42.

c.Pressure testing as described in regulation 43.

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2.10Under regulation 45 of the Building Regulations 2010, regulation 8 of the Building (Approved Inspectors etc.) Regulations 2010 and section 33 of the Building Act 1984, building control bodies have powers to make tests as they consider necessary to establish whether building work complies with the requirements of regulation 7.

2.11Those carrying out building work may voluntarily include testing in the activities they carry out to demonstrate that the work complies with the requirements of the regulations.

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The following are key terms used in this document:

BSI

The British Standards Institution is the UK national standards body. BSI publishes European standards in the UK as BS EN. Further information is available at: www.bsigroup.co.uk

Building control body

A local authority or an approved inspector.

CEN

The Comité Européen de Normalisation is the European standards body that prepares harmonised European product standards. Declarations of performance against such standards should provide sufficient information for any member state to allow the product onto its 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: www.cen.eu

EA

The European co-operation for 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. Further information is available at: www.european-accreditation.org

European Technical Assessments

A favourable technical assessment issued under the European Construction Products Regulation 2011 that allows a manufacturer to affix CE markings on their products. Further information is available at: www.eota.eu

ISO

The 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. Further information is available at: www.iso.org

Materials

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.

NANDO

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

UKAS

The 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. Further information is available at: www.ukas.com

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BS EN ISO 9000

Quality management systems. Fundamentals and vocabulary [2005]

BS EN ISO 9001

Quality management systems. Requirements [2008]

BS 8000-1

Workmanship on building sites. Code of practice for excavation and filling [1989]

BS 8000-2-1

Workmanship on building sites. Code of practice for concrete work. Mixing and transporting concrete [1990 + AMD 9324].

BS 8000-2-2

Workmanship on building sites. Code of practice for concrete work. Sitework with in situ and precast concrete [1990]

BS 8000-3

Workmanship on building sites. Code of practice for masonry [2001]

BS 8000-4

Workmanship on building sites. Code of practice for waterproofing [1989]

BS 8000-5

Workmanship on building sites. Code of practice for carpentry, joinery and general fixings [1990]

BS 8000-6

Workmanship on building sites. Code of practice for slating and tiling of roofs and claddings [1990]

BS 8000-7

Workmanship on building sites. Code of practice for glazing [1990]

BS 8000-8

Workmanship on building sites. Code of practice for plasterboard partitions and dry linings [1994]

BS 8000-9

Workmanship on building sites. Cementitious levelling screeds and wearing screeds. Code of practice [2003]

BS 8000-11

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 [2011]

BS 8000-12

Workmanship on building sites. Code of practice for decorative wallcoverings and painting [1989]

BS 8000-13

Workmanship on building sites. Code of practice for above ground drainage and sanitary appliances [1989]

BS 8000-14

Workmanship on building sites. Code of practice for below ground drainage [1989]

BS 8000-15

Workmanship on building sites. Code of practice for hot and cold water services (domestic scale) [1990]

BS 8000-16

Workmanship on building sites. Code of practice for sealing joints in buildings using sealants [1997 + A1:2010]

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Legislation

Building Act 1984 c.55 (as amended)

Building Regulations 2010 (SI 2010/2214) (as amended)

Building (Approved Inspectors etc.) Regulations 2010 (SI 2010/2215) (as amended)

Construction Products Regulation (305/2011/EU-CPR)

Gas Appliances Directive (2009/142/EC)

Pressure Equipment Directive (97/23/EC)

The Welsh Ministers (Transfer of Functions) (No. 2) Order 2009 (SI 2009/3019)

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The following publications give practical guidance on how to meet the Building Regulations. You can find the date of the edition approved by the Secretary of State at www.gov.uk.

Approved Document A Structure

Approved Document B Fire safety Volume 1: Dwellinghouses Volume 2: Buildings other than dwellinghouses

Approved Document C Site preparation and resistance to contaminants and moisture

Approved Document D Toxic substances

Approved Document E Resistance to the passage of sound

Approved Document F Ventilation

Approved Document G Sanitation, hot water safety and water efficiency

Approved Document H Drainage and waste disposal

Approved Document J Combustion appliances and fuel storage systems

Approved Document K Protection from falling, collision and impact

Approved Document L1A Conservation of fuel and power in new dwellings

Approved Document L1B Conservation of fuel and power in existing dwellings

Approved Document L2A Conservation of fuel and power in new buildings other than dwellings

Approved Document L2B Conservation of fuel and power in existing buildings other than dwellings

Approved Document M Access to and use of buildings Volume 1: Dwellings Volume 2: Buildings other than dwellings

Approved Document P Electrical safety – Dwellings

Approved Document Q Security – Dwellings

Approved Document R Physical infrastructure for high-speed electronic communications networks

Approved Document 7 Materials and workmanship

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The Building Regulations 2010, Approved Documents are available from:

RIBA Bookshops

Telephone orders/General enquiries: +44 (0)20 7496 8383 Email orders: sales@ribabookshops.com Or order online at: www.ribabookshops.com

© Crown Copyright 2018 The content of this publication, excluding logos, may be reproduced free of charge in any format or medium for research, private study or for internal circulation within an organisation. This is subject to it being reproduced accurately and not used in a misleading context. The material must be acknowledged as Crown copyright and the title and edition of the publication specified. This document/publication is value added. You may re-use the content (not including logos) free of charge in any format or medium, under the terms of the Open Government Licence. To view this licence, visit: http://www.nationalarchives.gov.uk/doc/open-government-licence/ or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or e-mail: psi@nationalarchives.gov.uk.

If you require this publication in an alternative format, please email: alternativeformats@communities.gov.uk. Copyright in the typographical arrangement, excluding logos, of the cover and internal page layouts of this publication rest with the Publisher.

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Structure

APPROVED DOCUMENT A

A1 Loading

A2 Ground movement

A3 Disproportionate collapse

For use in England*

2004 edition incorporating 2004, 2010 and 2013 amendments

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The main changes, which apply only to England*, are to:

•References to British Standard design standards

•Guidance on disproportionate collapse

•Wind maps

•Guidance on strip footings

•Materials and workmanship

There have been no changes to Part A of Schedule 1 to the Building Regulations.

MAIN CHANGES MADE BY THE 2010 AMENDMENTS

The 2010 amendments reflect the Building Regulations 2010 and Building (Approved Inspectors etc) Regulations 2010. The changes mainly reflect regulation number changes as a result of re-ordering. There have been no amendments to the substantive requirements in Part A of Schedule 1 to the Building Regulations.

MAIN CHANGES IN THE 2004 EDITION

The 2004 edition replaced the 1992 Edition (with 1994 and 2000 amendments edition). The main changes were:

•Guidance on the sizing of timber floors and roofs for traditional house construction removed, as the Timber Tables are now published by TRADA.

•Map of basic wind speeds revised.

•Stainless steel cavity wall ties specified for all houses regardless of their location.

•Guidance on masonry walls to dwellings extended.

•Guidance on concrete foundations to houses revised.

•Guidance on the design and construction of domestic garages extensively updated.

•Disproportionate collapse: the Application Limit to Requirement A3 (ie. the 5 storey limit) removed to bring all buildings under control of Requirement A3.

APPROVED DOCUMENTS

The following documents have been published to give practical guidance about how to meet the Building Regulations. You can find the date of the edition approved by the Secretary of State at www.planningportal.gov.uk.

Approved Document A Structure

Approved Document B: Volume 1 Fire safety – Dwellinghouses

Approved Document B: Volume 2 Fire safety – Buildings other than dwellinghouses

Approved Document C Site preparation and resistance to contaminants and moisture

Approved Document D Toxic substances

Approved Document E Resistance to the passage of sound

Approved Document F Ventilation

Approved Document G Sanitation, hot water safety and water efficiency

Approved Document H Drainage and waste disposal

Approved Document J Combustion appliances and fuel storage systems

Approved Document K Protection from falling, collision and impact

Approved Document L1A Conservation of fuel and power in new dwellings

Approved Document L1B Conservation of fuel and power in existing dwellings

Approved Document L2A Conservation of fuel and power in new buildings other than dwellings

Approved Document L2B Conservation of fuel and power in existing buildings other than dwellings

Approved Document M Access to and use of buildings

Approved Document P Electrical Safety – Dwellings

Approved Document 7 Materials and workmanship

* This approved document gives guidance for compliance with the Building Regulations for building work carried out in England. It also applies to building work carried out on excepted energy buildings in Wales as defined in the Welsh Ministers (Transfer of Functions) (No. 2) Order 2009.

This printing incorporates editorial amendments and corrections.

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DIAGRAMS

1.Size and proportion of residential buildings of not more than three storeys — 14

2.Size and proportion of non-residential buildings and annexes — 15

3.Determination of wall thickness — 16

4.Parapet walls: height — 17

5.Maximum floor area enclosed by structural walls — 18

6.Map showing wind speed in m/s for maximum height of buildings — 19

7.Maximum height of buildings — 21

8.Measuring storey and wall heights — 22

9.Declared compressive strength of masonry units — 24

10.Maximum span of floors — 25

11.Differences in ground levels — 26

12.Openings in a buttressing wall — 27

13.Buttressing — 28

14.Sizes of openings and recesses — 29

15.Lateral support by floors — 30

16.Lateral support at roof level — 31

17.Size and location of openings — 32

18.Wall thickness — 33

19.Lateral restraint at roof level — 34

20.Proportions for masonry chimneys — 35

21.Elevation of stepped foundation — 36

22.Piers and chimneys — 36

23.Foundation dimensions — 36

24.Area at risk of collapse in the event of an accident — 45

TABLES

1.Areas at risk from house longhorn beetle — 12

2.Wall types considered in this section — 13

3.Minimum thickness of certain external walls, compartment walls and separating walls — 16

4.Imposed loads — 18

5.Cavity wall ties — 23

6.Declared compressive strength of masonry units complying with BS EN 771-1 to -5 — 25

7.Normalised compressive strength of masonry units of clay and calcium silicate blocks complying with BS EN 771-1 and -2 — 25

8.Value of Factor ‘X’ — 29

9.Lateral support for walls — 29

10.Minimum width of strip footings — 37

11.Building consequence classes — 44

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THE APPROVED DOCUMENTS

This document is one of a series that has been approved by the First Secretary of State for the purpose of providing practical guidance with respect to the requirements of Schedule 1 to and Regulation 7 of the Building Regulations 2010 (SI 2010/2214) for England and Wales.

At the back of this document is a list of all the documents that have been approved and issued by the Secretary of State for this purpose.

Approved Documents are intended to provide guidance for some of the more common building situations. However, there may well be alternative ways of achieving compliance with the requirements. Thus there is no obligation to adopt any particular solution contained in an Approved Document if you prefer to meet the relevant requirement in some other way.

Other requirements

The guidance contained in an Approved Document relates only to the particular requirements of the Regulations which that document addresses. The building work will also have to comply with the requirements of any other relevant paragraphs in Schedule 1 to the Regulations.

There are Approved Documents which give guidance on each of the parts of Schedule 1 and on Regulation 7.

LIMITATION ON REQUIREMENTS

In accordance with Regulation 8, the requirements in Part A of Schedule 1 to the Building Regulations do not require anything to be done except for the purpose of securing reasonable standards of health and safety for persons in or about the buildings.

MATERIALS AND WORKMANSHIP

Any building work which is subject to the requirements imposed by Schedule 1 to the Building Regulations shall be carried out in accordance with regulation 7. Guidance on meeting these requirements on materials and workmanship is contained in Approved Document 7.

Building Regulations are made for specific purposes, primarily the health and safety, welfare and convenience of people and for energy conservation. Standards and other technical specifications may provide relevant guidance to the extent that they relate to these considerations. However, they may also address other aspects of performance or matters which, although they relate to health and safety etc., are not covered by the Building Regulations.

When an Approved Document makes reference to a named standard, the relevant version of the standard to which it refers is the one listed at the end of the publication. However, if this version has been revised or updated by the issuing standards body, the new version may be used as a source of guidance provided it continues to address the relevant requirements of the Regulations.

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OTHER HEALTH AND SAFETY LEGISLATION

Health and safety regulations such as the Workplace (Health, Safety and Welfare) Regulations 1992 may impose requirements on employers and those in control of buildings used as workplaces in relation to certain physical characteristics of the workplace. There are also requirements in health and safety law which affect building design. In particular, regulation 11 of the Construction (Design and Management) Regulations 2007 places duties on designers including the need to take account of the Workplace (Health, Safety and Welfare) Regulations 1992 which relate to the design of, and materials used in, any structure intended for use as a workplace.

Where such regulations apply there may be confusion as to whether the Building Regulations or health and safety requirements take precedence, as both will apply. Where an inspector for the purposes of the Health and Safety at Work etc. Act 1974 has identified a contravention of such health and safety regulations they may seek to serve an improvement notice to secure compliance. In such circumstances the inspector is prevented by virtue of Section 23(3) of the Health and Safety at Work etc. Act 1974 from requiring measures which are more onerous than necessary to comply with any requirements of the Building Regulations, unless the specific requirement of health and safety regulations are themselves more onerous.

OTHER FORMS OF HOUSE CONSTRUCTION

This Approved Document includes guidance on structural elements of residential buildings of traditional masonry construction. It is recognised, however, that there are other suitable forms of construction in use in the housing sector some of which (e.g. timber framed) have been in common use for a number of years and have demonstrated an adequate performance in compliance with the A1 requirement. Such alternative forms include prefabricated timber, light steel and precast concrete framed construction.

A number of guidance documents relating to these alternative forms are presently being developed by industry. The intention is to reference these in this Approved Document as soon as they become available and are approved by the Secretary of State.

BRITISH STANDARDS

The British Standards Institution notified the British Standards for structural design referenced in the 2004 edition of this Approved Document as withdrawn on 31 March 2010. British Standards for structural design based upon the Eurocodes were correspondingly implemented by the British Standards Institution on 1 April 2010 and it is these standards with their UK National Annexes which are now referenced in this Approved Document as practical guidance on meeting Part A requirements.

There may be alternative ways of achieving compliance with the requirements and there might be cases where it can be demonstrated that the use of withdrawn standards no longer maintained by the British Standards Institution continues to meet Part A requirements.

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This Approved Document deals with the following Requirements which are contained in the Building Regulations 2010.

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Introduction

0.1In the Secretary of State’s view the requirements of A1 and A2 will be met by following the recommendations given in the documents listed in Section 1 or by adopting the guidance in Sections 2–4:

a.Section 1 is relevant to all building types and lists Codes, Standards and other references for structural design and construction but, where they do not give precise guidance, consideration should be given to paragraph 0.2.

b.Section 2 give sizes of structural elements for certain residential buildings and other small buildings of traditional construction.

c.Section 3 gives guidance on the support and fixing of wall cladding.

d.Section 4 gives guidance where roofs are to be re-covered as a material alteration as defined in the Regulations.

0.2The safety of a structure depends on the successful combination of design and completed construction, particularly:

a.The design should be based on identification of the hazards to which the structure is likely to be subjected and assessment of the risks. The selection of relevant critical situations for design should be made reflecting the conditions that can reasonably be foreseen during future use.

b.Loading. Dead load, imposed load and wind load should be in accordance with the current Codes of practice referred to in Section 1 of this document.

c.Properties of materials.

d.Detailed design and assembly of the structure.

e.Safety factors.

f.Workmanship.

The numeric values of safety factors, whether expressed explicitly or implicitly in design equations, or design values, should be derived from considerations of the above aspects of design and construction as a whole. A change in any one of these aspects may disturb the safety of the structure.

Loads used in calculations should allow for possible dynamic, concentrated and peak load effects that may occur.

0.3Grandstands and structures erected in places of public assembly may need to sustain the synchronous or rhythmic movement of numbers of people. It is important to ensure that the design of the structure takes these factors into account so as to avoid the structure being impaired or causing alarm to people using the structure.

Guidance on the design and testing of grandstands may be found in ‘Dynamic performance requirements for permanent grandstands subject to crowd action – Recommendations for management, design and assessment’ published by The Institution of Structural Engineers, December 2008.

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Introduction

1.1This section is relevant to all building types and lists codes, standards and other references for structural design and construction.

References

1.2Basis of structural design and loading:

Eurocode: Basis of Structural Design

BS EN 1990:2002+A1:2005 Eurocode – Basis of structural design; with UK National Annex to BS EN 1990:2002+A1:2005

Eurocode 1: Actions on Structures

BS EN 1991-1-1:2002 Eurocode 1: Actions on structures – Part 1.1: General actions – Densities, self weight, imposed loads for buildings; with UK National Annex to BS EN 1991-1-1:2002

BSI PD 6688-1-1:2011 Published Document – Recommendations for the design of structures to BS EN 1991-1-1

BS EN 1991-1-3:2003 Eurocode 1: Actions on structures – Part 1.3: General actions – Snow loads; with UK National Annex to BS EN 1991-1-3:2003

BS EN 1991-1-4:2005+A1:2010 Eurocode 1: Actions on structures – Part 1.4: General actions – Wind actions; with UK National Annex to BS EN 1991-1-4:2005+A1:2010

BSI PD 6688-1-4:2009 Published Document – Background information to the National Annex to BS EN 1991-1-4 and additional guidance

BS EN 1991-1-5:2003 Eurocode 1: Actions on structures – Part 1.5: General actions – Thermal actions; with UK National Annex to BS EN 1991-1-5:2003

BS EN 1991-1-6:2005 Eurocode 1: Actions on structures – Part 1.6: General actions – Actions during execution; with UK National Annex to BS EN 1996-1-6:2005

BS EN 1991-1-7:2006 Eurocode 1: Actions on structures – Part 1.7: General actions – Accidental actions; with UK National Annex to BS EN 1991-1-7:2006

BSI PD 6688-1-7:2009 Published Document – Recommendations for the design of structures to BS EN 1991-1-7

BS EN 1991-3:2006 Eurocode 1: Actions on structures – Part 3: Actions induced by cranes and machinery; with UK National Annex to BS EN 1991-3:2006

1.3Structural work of reinforced, pre-stressed or plain concrete:

Eurocode 2: Design of Concrete Structures

BS EN 1992-1-1:2004 Eurocode 2: Design of concrete structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1992-1-1:2004

BSI PD 6687-1:2010 Published Document – Background paper to the UK National Annexes to BS EN 1992-1 and BS EN 1992-3

BS EN 13670:2009 Execution of concrete structures

1.4Structural work of steel:

Eurocode 3: Design of Steel Structures

BS EN 1993-1-1:2005 Eurocode 3: Design of steel structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1993-1-1:2005

BS EN 1993-1-3:2006 Eurocode 3: Design of steel structures – Part 1.3: General rules – Supplementary rules for cold-formed members and sheeting; with UK National Annex to BS EN 1993-1-3:2006

BS EN 1993-1-4:2006 Eurocode 3: Design of steel structures – Part 1.4: General rules – Supplementary rules for stainless steels; with UK National Annex to BS EN 1993-1-4:2006

BS EN 1993-1-5:2006 Eurocode 3: Design of steel structures – Part 1.5: Plated structural elements; with UK National Annex to BS EN 1993-1-5:2006

BS EN 1993-1-7:2007 Eurocode 3: Design of steel structures – Part 1.7: Plated structures subject to out of plane loading

BS EN 1993-1-8:2005 Eurocode 3: Design of steel structures – Part 1.8: Design of joints; with UK National Annex to BS EN 1993-1-8:2005

BS EN 1993-1-9:2005 Eurocode 3: Design of steel structures – Part 1.9: Fatigue; with UK National Annex to BS EN 1993-1-9:2005

BSI PD 6695-1-9:2008 Published Document – Recommendations for the design of structures to BS EN 1993-1-9

BS EN 1993-1-10:2005 Eurocode 3: Design of steel structures – Part 1.10: Material toughness and through-thickness properties; with UK National Annex to BS EN 1993-1-10:2005

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BSI PD 6695-1-10:2009 Published Document – Recommendations for the design of structures to BS EN 1993-1-10

BS EN 1993-1-11:2006 Eurocode 3: Design of steel structures – Part 1.11: Design of structures with tension components; with UK National Annex to BS EN 1993-1-11:2006

BS EN 1993-1-12:2007 Eurocode 3: Design of steel structures – Part 1.12: Additional rules for the extension of EN 1993 up to steel grades S 700; with UK National Annex to BS EN 1993-1-12:2007

BS EN 1993-5:2007 Eurocode 3: Design of steel structures – Part 5: Piling; with UK National Annex to BS EN 1993-5:2007+A1:2012

BS EN 1993-6:2007 Eurocode 3: Design of steel structures – Part 6: Crane supporting structures; with UK National Annex to BS EN 1993-6:2007

BS EN 1090-2:2008+A1:2011 Execution of steel structures and aluminium structures – Part 2: Technical requirements for the execution of steel structures

BRE Digest 437 Industrial platform floors: mezzanine and raised storage

1.5 Structural work of composite steel and concrete:

Eurocode 4: Design of Composite Steel and Concrete Structures

BS EN 1994-1-1:2004 Eurocode 4: Design of composite steel and concrete structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1994-1-1:2004

1.6 Structural work of timber:

Eurocode 5: Design of Timber Structures

BS EN 1995-1-1:2004+A1:2008 Eurocode 5: Design of timber structures – Part 1.1: General – Common rules and rules for buildings; with UK National Annex to BS EN 1995-1-1:2004+A1:2008

BSI PD 6693-1:2012 Published Document – Recommendations for the design of timber structures to Eurocode 5: Design of timber structures Part 1: General – Common rules and rules for buildings

BS 8103-3:2009 Structural design of low-rise buildings – Part 3: Code of practice for timber floors and roofs for housing

1.7 Structural work of masonry:

Eurocode 6: Design of Masonry Structures

BS EN 1996-1-1:2005+A1:2012 Eurocode 6: Design of masonry structures – Part 1.1: General rules for reinforced and unreinforced masonry structures; with UK National Annex to BS EN 1996-1-1:2005+A1:2012

BS EN 1996-2:2006 Eurocode 6: Design of masonry structures – Part 2: Design considerations, selection of materials and execution of masonry; with UK National Annex to BS EN 1996-2:2006

BSI PD 6697:2010 Published Document – Recommendations for the design of masonry structures to BS EN 1996-1-1 and BS EN 1996-2

BS EN 1996-3:2006 Eurocode 6: Design of masonry structures – Part 3: Simplified calculation methods for unreinforced masonry structures; with UK National Annex to BS EN 1996-3:2006

BS 8103-1:2011 Structural design of low-rise buildings – Part 1: Code of Practice for stability, site investigation, foundations, precast concrete floors and ground floor slabs for housing

BS 8103-2:2005 Structural design of low-rise buildings – Part 2: Code of practice for masonry walls for housing

1.8 Geotechnical work and foundations:

Eurocode 7: Geotechnical Design

BS EN 1997-1:2004 Eurocode 7: Geotechnical design – Part 1: General rules; with UK National Annex to BS EN 1997-1:2004

BS EN 1997-2:2007 Eurocode 7: Geotechnical design – Part 2: Ground investigation and testing; with UK National Annex to BS EN 1997-2:2007

1.9 Seismic aspects:

Eurocode 8: Design of Structures for Earthquake Resistance

BS EN 1998-1:2004+A1:2013 Eurocode 8: Design of structures for earthquake resistance – Part 1: General rules, seismic actions and rules for buildings; with UK National Annex to BS EN 1998-1:2004

BS EN 1998-5:2004 Eurocode 8: Design of structures for earthquake resistance – Part 5: Foundations, retaining structures and geotechnical aspects; with UK National Annex to BS EN 1998-5:2004

BSI PD 6698:2009 Published Document – Recommendations for the design of structures for earthquake resistance to BS EN 1998

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1.10 Structural work of aluminium:

Eurocode 9: Design of Aluminium Structures

BS EN 1999-1-1:2007+A1:2009 Eurocode 9: Design of aluminium structures – Part 1.1: General structural rules; with UK National Annex to BS EN 1999-1-1:2007+A1:2009

BS EN 1999-1-3:2007+A1:2011 Eurocode 9: Design of aluminium structures – Part 1.3: Structures susceptible to fatigue; with UK National Annex to BS EN 1999-1-3:2007+A1:2011

BSI PD 6702-1:2009 Published Document – Structural use of aluminium – Part 1: Recommendations for the design of aluminium structures to BS EN 1999

BS EN 1999-1-4:2007+A1:2011 Eurocode 9: Design of aluminium structures – Part 1.4: Cold-formed structural sheeting; with UK National Annex to BS EN 1999-1-4:2007

BS EN 1999-1-5:2007 Eurocode 9: Design of aluminium structures – Part 1.5: Shell structures; with UK National Annex to BS EN 1999-1-5:2007

BS EN 1090-3:2008 Execution of steel structures and aluminium structures – Part 3: Technical requirements for aluminium structures

BSI PD 6705-3:2009 Published Document – Structural use of steel and aluminium – Part 3: Recommendations for the design of aluminium structures to BS EN 1090-3

Ground movement (Requirement A2b)

1.11There may be known or recorded conditions of ground instability, such as that arising from landslides, disused mines or unstable strata which, if ignored, can have a devastating effect on the safety of a building and its environs. Such conditions should be taken into account in the design of the building and its foundations. Attention is drawn to DOE Planning Policy Guidance Note 14 Development on unstable land (obtainable from The Stationery Office), which sets out the broad planning and technical issues relating to development on unstable land.

The Department has also sponsored a series of reviews aimed at determining the scale and nature of problems arising from mining instability, natural underground cavities and adverse foundation conditions. Databases of both subsidence incidents and subsidence potential produced from these reviews are available from the following licence holders:

British Geological Survey, Sir Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG.

Landmark, 7 Abbey Court, Eagle Way, Exeter, Devon EX2 7HY.

Peter Brett Associates, 16 Westcote Road, Reading, Berkshire RG2 0DE.

Catalytic Data Ltd, The Spinney, 19 Woodlands Road, Bickley, Kent BR1 2AD.

The reports from these reviews, which include 1:250,000 scale maps showing the distribution of the physical constraints, are available from the following organisations:

Arup Geotechnics, 1991. Review of mining instability in Great Britain.

Obtainable from Arup Geotechnics, Bede House, All Saints, Newcastle-upon-Tyne NE1 2EB.

Applied Geology Ltd, 1994. Review of instability due to natural underground cavities in Great Britain.

Obtainable from Kennedy & Donkin Ltd, 14 Calthorpe Road, Edgbaston, Birmingham B15 1TH.

Wimpey Environmental Ltd, and National House Building Council, 1995. Foundation conditions in Great Britain, a guide for planners and developers. Obtainable from ESNR International Ltd, 16 Frogmore Road, Hemel Hempstead, Hertfordshire HP3 9RW.

Existing buildings

1.12Compliance with Part A (Structure) is required in certain classes of change of use of a building, subject to the control of Regulations 5 and 6. Guidance relevant to structural appraisals related to ‘change of use’ is given in the following documents:

a.BRE Digest 366: Structural Appraisal of Existing Buildings, Including for a Material Change of Use, 2012

b.The Institution of Structural Engineers Technical Publication Appraisal of Existing Structures (third edition), 2010

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General

2.1This section is presented as follows:

Section 2A

Basic requirements for stability.

Section 2B

Sizes of certain timber members in floors and roofs for dwellings.

Areas at risk from house longhorn beetle.

Section 2C

Thickness of masonry walls in certain residential buildings of not more than three storeys, small single-storey non-residential buildings and annexes.

Section 2D

Proportions for masonry chimneys.

Section 2E

Foundations of plain concrete.

2.2Section 2A gives general rules which must be observed in following Sections 2B and 2C. Sections 2B to 2E may be used independently of each other.

Throughout this section the diagrams are only illustrative and do not show all the details of construction.

Definitions

2.3The following meanings apply to terms throughout this section:

Buttressing wall A wall designed and constructed to afford lateral support to another wall perpendicular to it, support being provided from the base to the top of the wall.

Cavity width The horizontal distance between the two leaves of a cavity wall.

Compartment wall A wall constructed as a compartment wall to meet the requirements of regulation B3(2).

Dead load The load due to the weight of all walls, permanent partitions, floors, roofs and finishes including services, and all other permanent construction.

Imposed load The load assumed to be produced by the intended occupancy or use, including the weight of movable partitions, distributed, concentrated, impact, inertia and snow loads, but excluding wind loads.

Pier A member which forms an integral part of a wall, in the form of a thickened section at intervals along the wall, so as to afford lateral support to the wall to which it is bonded or securely tied.

Separating wall A wall or part of a wall which is common to adjoining buildings, and constructed to meet the requirements of regulation B3(2).

Spacing The distance between the longitudinal centres of any two adjacent timber members of the same type, measured in the plane of floor, ceiling or roof structure.

Span The distance measured along the centre line of a member between the centres of any two adjacent bearings or supports.

Supported wall A wall to which lateral support is afforded by a combination of buttressing walls, piers or chimneys acting in conjunction with floor(s) or roof.

Wind load The load due to the effect of wind pressure or suction.

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2A1This section must be used in conjunction with sections 2B and 2C and its principles relate to all forms of low-rise residential buildings.

2A2Adequate provision shall be made to ensure that the building is stable under the likely imposed and wind loading conditions. This will commonly necessitate meeting the following requirements:

a.That the overall size and proportioning of the building are limited in accordance with the specific guidance for each form of construction.

b.That a suitable layout of walls (both internal and external) forming a robust 3 dimensional box structure in plan is constructed with restriction on the maximum size of cells measured in accordance with the specific guidance for each form of construction.

c.That the internal and external walls are adequately connected either by masonry bonding or by using mechanical connections.

d.That the intermediate floors and roof are of such construction and interconnection with the walls that they provide local support to the walls and also act as horizontal diaphragms capable of transferring the wind forces to buttressing elements of the building.

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Sizing of members

2B1Guidance on the sizing of certain members in floors and roofs is given in ‘Span tables for solid timber members in floors, ceilings and roofs (excluding trussed rafter roofs) for dwellings’, published by TRADA, available from Chiltern House, Stocking Lane, Hughenden Valley, High Wycombe, Bucks HP14 4ND.

Alternative guidance is available in BS EN 1995-1-1:2004 Design of timber structures with its UK National Annex and additional guidance given in BSI Published Document PD 6693-1:2012 and also BS 8103-3:2009 Structural design of low-rise buildings, Code of practice for timber floors and roofs for housing.

House longhorn beetle

2B2In the geographical areas specified in Table 1, softwood timber for roof construction or fixed in the roof space, including ceiling joists within the void spaces of the roof, should be adequately treated to prevent infestation by the house longhorn beetle (Hylotrupes bajulus L.).

Guidance on suitable preservative treatments is given within The Wood Protection Association’s manual ‘Industrial Wood Preservation: Specification and Practice’ (2012), available from 5C Flemming Court, Castleford, West Yorkshire, WF10 5HW.

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Application

2C1This section applies to the following building types:

a.residential buildings of not more than three storeys;

b.small single-storey non-residential buildings;

c.small buildings forming annexes to residential buildings (including garages and outbuildings).

Wall types

2C2Only the types of wall given in Table 2, which must extend to the full storey height, and parapet walls are considered in this section.

The use of this section

2C3When using this section it should be noted that:

a.this section must be used in conjunction with section 2A;

b.if wall thickness is to be determined according to paragraphs 2C5 to 2C13, all appropriate design conditions given in this section must be satisfied;

c.walls should comply with the relevant requirements of BS EN 1996-2:2006 with its UK National Annex and additional guidance given in BSI Published Document PD 6697:2010, except as regards to the conditions given in paragraphs 2C4 and 2C14 to 2C38;

d.in formulating the guidance of this section the worst combination of circumstances likely to arise was taken into account. If a requirement of this part is considered too onerous in a particular case it may be appropriate to consider a minor departure on the basis of judgement and experience, or to show adequacy by calculation in respect of the aspect of the wall which is subject to the departure rather than for the entire wall;

e.the guidance given is based upon the compressive strengths of bricks and blocks being not less than indicated in Tables 6 and 7.

BS EN 1996-1-1:2005 with its UK National Annex gives design strengths for walls where the suitability for use of masonry units of other compressive strengths is being considered.

Conditions relating to the building of which the wall forms part

2C4This section applies only to buildings having proportions within the following parameters (see Diagrams 1 and 2):

a.residential buildings of not more than three storeys:

i.the maximum height of the building measured from the lowest finished ground level adjoining the building to the highest point of any wall or roof should not be greater than 15m, subject to the limits of paragraph 2C16;

ii.the height of the building H should not exceed twice the least width of the building W1;

iii.the height of the wing H2 should not exceed twice the least width of the wing W2 where the projection P exceeds twice the width W2;

b.small single-storey non-residential buildings: height H should not exceed 3m and W (being the greatest length or width of the building) should not exceed 9m (see Diagram 2), subject to the limits of paragraph 2C16;

c.annexes: height H as variously indicated in Diagram 2 should not exceed 3m, subject to the limits of paragraph 2C16.

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Thickness of walls

2C5General wall thickness may be determined according to this section provided:

a.conditions relating to the building of which the wall forms part (see paragraphs 2C4, 2C14 to 2C16, 2C38); and

b.conditions relating to the wall (see paragraphs 2C17 to 2C37) are met. (See Diagram 3.)

2C6Solid external walls, compartment walls and separating walls in coursed brickwork or blockwork: Solid walls constructed of coursed brickwork or blockwork should be at least as thick as 1/16 of the storey height. Further requirements are given in Table 3.

2C7Solid external walls, compartment walls and separating walls in uncoursed stone, flints, etc.: The thickness of walls constructed in uncoursed stone, flints, clunches, bricks or other burnt or vitrified material should not be less than 1.33 times the thickness determined by paragraph 2C6.

2C8Cavity walls in coursed brickwork or blockwork: All cavity walls should have leaves at least 90mm thick and cavities at least 50mm wide. The wall ties should have a horizontal spacing of 900mm and a vertical spacing of 450mm, or alternatively should be spaced such that the number of wall ties per square metre is not less than 2.5 ties/m². Wall ties should also be provided, spaced not more than 300mm apart vertically, within a distance of 225mm from the vertical edges of all openings, movement joints and roof verges. For selection of wall ties for use in a range of cavity widths refer to Table 5. For specification of cavity wall ties refer to paragraph 2C19.

For external walls, compartment walls and separating walls in cavity construction, the combined thickness of the two leaves plus 10mm should not be less than the thickness determined by paragraph 2C6 and Table 3 for a solid wall of the same height and length.

2C9Walls providing vertical support to other walls: Irrespective of the material used in the construction, a wall should not be less in thickness than any part of the wall to which it gives vertical support.

2C10Internal load-bearing walls in brickwork or blockwork (except compartment walls or separating walls): All internal load-bearing walls should have a thickness not less than:

(specified thickness from Table 3) / 2 – 5mm

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except for a wall in the lowest storey of a three storey building, carrying load from both upper storeys, which should have a thickness as determined by the equation or 140mm whichever is the greatest.

2C11Parapet walls: The minimum thickness and maximum height of parapet walls should be as given in Diagram 4.

2C12Single leaves of certain external walls: The single leaf of external walls of small single-storey non-residential buildings and of annexes need be only 90mm thick, notwithstanding paragraphs 2C38.

2C13Modular bricks and blocks: Where walls are constructed of bricks or blocks having modular dimensions, wall thicknesses prescribed in this section which derive from a dimension of brick or block may be reduced by an amount not exceeding the deviation from work size permitted by a British Standard relating to equivalent sized bricks or blocks made of the same material.

2C14Maximum floor area: The guidance of this section assumes that no floor enclosed by structural walls on all sides exceeds 70m², and that no floor without a structural wall on one side exceeds 36m². (See Diagram 5.)

2C15Imposed loads on roofs, floors and ceilings: The design considerations given in this section are intended to be adequate for the imposed loads given in Table 4.

2C16Maximum height of buildings: The design guidance in this section is based on BS EN 1991-1-4:2005 with its UK National Annex. The maximum heights of buildings given in Table c of Diagram 7 correlate to various site exposure conditions and wind speeds. A map showing wind speeds is given in Figure 1 of Diagram 6.

Conditions relating to the wall

2C17Maximum allowable length and height of the wall: This section does not deal with walls longer than 12m, measured from centre to centre of buttressing walls, piers or chimneys providing restraint, or with walls exceeding 12m in height (see also Table 3).

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2C18Rules of measurement for heights of walls and storeys: The height of a wall or a storey should be measured in accordance with the rules in Diagram 8.

Construction materials and workmanship

2C19Wall ties: Wall ties should comply with BS EN 845-1 and should be material references 1 or 3 in BS EN 845-1 Table A1 austenitic stainless steel. Wall ties should be selected in accordance with Table 5 of this Approved Document.

2C20Masonry units: Walls should be properly bonded and solidly put together with mortar and constructed of masonry units conforming to:

a.clay bricks or blocks to BS EN 771-1;

b.calcium silicate bricks or blocks to BS EN 771-2;

c.concrete bricks or blocks to BS EN 771-3 or BS EN 771-4;

d.manufactured stone to BS EN 771-5;

e.square dressed natural stone to the appropriate requirements described in BS EN 771-6.

2C21Compressive strength of masonry units: Minimum compressive strength requirements for masonry units according to BS EN Standards are given in Diagram 9, where the masonry units indicated for Conditions A, B and C should have declared compressive strengths of not less than the values given in Table 6. Normalised compressive strengths for block sized clay and calcium silicate masonry units not complying with brick dimensional format are given in Table 7.

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2C22Mortar: Mortar should be:

a.one of the following:

i.Mortar designation (iii) according to BS EN 1996-1-1:2005 with its UK National Annex;

ii.Strength class M4 according to BS EN 998-2:2010;

iii.1:1:5 to 6 CEM I, lime, and fine aggregate measured by volume of dry materials, or

b.of equivalent or greater strength and durability to the specifications in a. above.

Loading on walls

2C23Maximum span of floors: The maximum span for any floor supported by a wall is 6m where the span is measured centre to centre of bearing (see Diagram 10).

2C24Other loading conditions:

a.Vertical loading on walls should be distributed. This may be assumed for concrete floor slabs, precast concrete floors, and timber floors designed in accordance with section 2B, and where the bearing length for lintels is 150mm or greater. Where a lintel has a clear span of 1200mm or less the bearing length may be reduced to 100mm.

b.Differences in level of ground or other solid construction between one side of the wall and the other should be less than 4 times the thickness of the wall as shown in Diagram 11.

c.The combined dead and imposed load should not exceed 70kN/m at base of wall (see Diagram 11).

d.Walls should not be subjected to lateral load other than from wind, and that covered by paragraph 2C24(b).

End restraint

2C25Vertical lateral restraint to walls The ends of every wall should be bonded or otherwise securely tied throughout their full height to a buttressing wall, pier or chimney. Long walls may be provided with intermediate buttressing walls, piers or chimneys dividing the wall into distinct lengths within each storey; each distinct length is a supported wall for the purposes of this section. The intermediate buttressing walls, piers or chimneys should provide lateral restraint to the full height of the supported wall, but they may be staggered at each storey.

2C26Buttressing walls If the buttressing wall is not itself a supported wall its thickness T2 should not be less than:

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Notes

1Floor slabs in figure b have been omitted for clarity and may be on either side of the walls shown.

2Cavity walls should be tied in accordance with Table 5.

3These recommendations apply only to circumstances where there is a full storey height of masonry above the upper retained level.

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a.half the thickness required by this section for an external or separating wall of similar height and length less 5mm; or

b.75mm if the wall forms part of a dwelling house and does not exceed 6m in total height and 10m in length; and

c.90mm in other cases.

The length of the buttressing wall should be at least 1/6 of the overall height of the supported wall and be bonded or securely tied to the supporting wall and at the other end to a buttressing wall, pier or chimney.

The size of any opening in the buttressing wall should be restricted as shown in Diagram 12.

2C27Design criteria for piers and chimneys providing restraint:

a.piers should measure at least 3 times the thickness of the supported wall and chimneys twice the thickness, measured at right angles to the wall. Piers should have a minimum width of 190mm (see Diagram 13);

b.the sectional area on plan of chimneys (excluding openings for fireplaces and flues) should be not less than the area required for a pier in the same wall, and the overall thickness should not be less than twice the required thickness of the supported wall (see Diagram 13).

Openings, recesses, overhangs and chases

2C28General: The number, size and position of openings and recesses should not impair the stability of a wall or the lateral restraint afforded by a buttressing wall to a supported wall. Construction over openings and recesses should be adequately supported.

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2C29Dimensional criteria for openings and recesses: The dimensional criteria are given in Diagram 14 and Table 8. No openings should be provided in walls below ground floor except for small holes for services and ventilation, etc. which should be limited to a maximum area of 0.1m² at not less than 2m centres.

2C30Chases:

a.vertical chases should not be deeper than 1/3 of the wall thickness or, in cavity walls, 1/3 of the thickness of the leaf;

b.horizontal chases should not be deeper than 1/6 of the thickness of the leaf of the wall;

c.chases should not be so positioned as to impair the stability of the wall, particularly where hollow blocks are used.

2C31Overhangs: The amount of any projection should not impair the stability of the wall.

Lateral support by roofs and floors

2C32A wall in each storey of a building should extend to the full height of that storey, and have horizontal lateral supports to restrict movement of the wall at right angles to its plane.

2C33Floors and roofs should:

a.act to transfer lateral forces from walls to buttressing walls, piers or chimneys; and

b.be secured to the supported wall by connections specified in paragraphs 2C34 and 2C35.

2C34The requirements for lateral restraint of walls at roof and floor levels are given in Table 9 and guidance on satisfying the requirements is given in paragraphs 2C35 and 2C36.

2C35Walls should be strapped to floors above ground level, at intervals not exceeding 2m and as shown in Diagram 15, by tension straps conforming to BS EN 845-1. For corrosion resistance purposes, the tension straps should be material reference 14 or 16.1 or 16.2 (galvanised steel) or other more resistant

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specifications including material references 1 or 3 (austenitic stainless steel). The declared tensile strength of tension straps should not be less than 8kN.

Tension straps need not be provided:

a.in the longitudinal direction of joists in houses of not more than 2 storeys, if the joists are at not more than 1.2m centres and have at least 90mm bearing on the supported walls or 75mm bearing on a timber wall-plate at each end, and

b.in the longitudinal direction of joists in houses of not more than 2 storeys, if the joists are carried on the supported wall by joist hangers in accordance with BS EN 845-1 of the restraint type described by additional guidance given in BSI Published Document PD 6697:2010 and shown in Diagram 15(c), and are incorporated at not more than 2m centres, and

c.when a concrete floor has at least 90mm bearing on the supported wall (see Diagram 15(d)), and

d.where floors are at or about the same level on each side of a supported wall, and contact between the floors and wall is either continuous or at intervals not exceeding 2m. Where contact is intermittent, the points of contact should be in line or nearly in line on plan (see Diagram 15(e)).

2C36Gable walls should be strapped to roofs as shown in Diagram 16(a) and (b) by tension straps as described in 2C35.

Vertical strapping at least 1m in length should be provided at eaves level at intervals not exceeding 2m as shown in Diagram 16(c) and (d). Vertical strapping may be omitted if the roof:

a.has a pitch of 15° or more, and

b.is tiled or slated, and

c.is of a type known by local experience to be resistant to wind gusts, and

d.has main timber members spanning onto the supported wall at not more than 1.2m centres.

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Interruption of lateral support

2C37Where an opening in a floor or roof for a stairway or the like adjoins a supported wall and interrupts the continuity of lateral support, the following conditions should be satisfied for the purposes of Section 2C:

a.the maximum permitted length of the opening is to be 3m, measured parallel to the supported wall, and

b.where a connection is provided by means other than by anchor, this should be provided throughout the length of each portion of the wall situated on each side of the opening, and

c.where a connection is provided by mild steel anchors, these should be spaced closer than 2m on each side of the opening to provide the same number of anchors as if there were no opening, and

d.there should be no other interruption of lateral support.

Small single-storey non-residential buildings and annexes

2C38 Size and proportion

i. General

The guidance given applies in the following circumstances:

a.The floor area of the building or annexe does not exceed 36m².

b.The walls are solidly constructed in brickwork or blockwork using materials which comply with paragraphs 2C19 to 2C22.

c.Where the floor area of the building or annexe exceeds 10m² the walls have a mass of not less than 130kg/m².

d.Access to the roof is only for the purposes of maintenance and repair.

e.The only lateral loads are wind loads.

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f.The maximum length or width of the building or annexe does not exceed 9m.

g.The height of the building or annexe does not exceed the lower value derived from Diagram 2.

h.The roof is braced at rafter level, horizontally at eaves level and at the base of any gable by roof decking, rigid sarking or diagonal timber bracing, as appropriate, in accordance with BS EN 1995-1-1:2004 with its UK National Annex and additional guidance given in BSI Published Document PD 6693-1:2012 or BS 8103-3:2009.

i.Walls are tied to the roof structure vertically and horizontally in accordance with paragraphs 2C32 to 2C36 and with horizontal lateral restraint at roof level in accordance with paragraph (iv) below.

j.The roof structure of an annexe is secured to the structure of the main building at both rafter and eaves level.

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(ii) Size and location of openings

One or two major openings not more than 2.1m in height are permitted in one wall of the building or annexe only. The width of a single opening or the combined width of two openings should not exceed 5m.

The only other openings permitted in a building or annexe are for windows and a single leaf door. The size and location of these openings should be in accordance with Diagram 17.

(iii) Wall thickness and recommendations for piers

The walls should have a minimum thickness of 90mm.

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Walls which do not contain a major opening but exceed 2.5m in length or height should be bonded or tied to piers for their full height at not more than 3m centres as shown in Diagram 18a. Walls which contain one or two major openings should in addition have piers as shown in Diagrams 18b and 18c. Where ties are used to connect piers to walls they should be flat, 20mm x 3mm in cross section, be in stainless steel in accordance with paragraph 2C19, be placed in pairs and be spaced at not more than 300mm centre vertically.

(iv)Horizontal lateral restraint at roof level Walls should be tied horizontally at no more than 2m centres to the roof structure at eaves level, base of gables and along roof slopes as shown in Diagram 19 with straps fixed in accordance with paragraphs 2C35 and 2C36. Where straps cannot pass through a wall they should be adequately secured to the masonry using suitable fixings. Isolated columns should also be tied to the roof structure (see Diagram 19).

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Section 2D: Proportions for masonry chimneys above the roof surface

Height to width relationship

2D1Where a chimney is not adequately supported by ties or securely restrained in any way, its height if measured from the highest point of intersection with the roof surface, gutter, etc. should not exceed 4.5W, provided the density of the masonry is greater than 1500kg/m³, where:

W is the least horizontal dimension of the chimney measured at the same point of intersection, and H is measured to the top of any chimney pot or other flue terminal (see Diagram 20).

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Section 2E: Foundations of plain concrete

Conditions relating to the ground

2E1There should not be:

a.non-engineered fill (as described in BRE Digest 427) or wide variation in ground conditions within the loaded area; nor

b.weaker or more compressible ground at such a depth below the foundation as could impair the stability of the structure.

Design provisions

2E2The following design provisions relate to foundations:

a.the foundations should be situated centrally under the wall;

b.for foundations in chemically aggressive soil conditions guidance in BS 8500-1 and BRE Special Digest 1 should be followed. In non-aggressive soils, concrete should be composed of Portland cement to BS EN 197-1 and -2 and fine and coarse aggregate conforming to BS EN 12620 and the mix should comply with one of the following recommendations:

i.in proportion of 50kg of Portland cement to not more than 200kg (0.1m³) of fine aggregate and 400kg (0.2m³) of coarse aggregate; or

ii.grade ST2 or grade GEN I concrete to BS 8500-2;

c.minimum thickness T of concrete foundation should be 150mm or P, whichever is the greater, where P is derived using Table 10 and Diagram 23. Trench fill foundations may be used as an acceptable alternative to strip foundations;

d.foundations stepped on elevation should overlap by twice the height of the step, by the thickness of the foundation, or 300mm, whichever is greater (see Diagram 21).

For trench fill foundations the overlap should be twice the height of the step or 1m, whichever is greater;

e.steps in foundations should not be of greater height than the thickness of the foundation (see Diagram 21);

f.foundations for piers, buttresses and chimneys should project as indicated in Diagram 22 and the projection X should never be less than the value of P where there is no local thickening of the wall.

Minimum width of strip foundations

2E3The recommended minimum widths of foundations given in Table 10 may be used.

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The table is applicable only within the strict terms of the criteria described within it.

Minimum depth of strip foundations

2E4Except where strip foundations are founded on rock, the strip foundations should have a minimum depth of 0.45m to their underside, to avoid the action of frost. This depth, however, will commonly need to be increased in areas subject to long periods of frost or in order to transfer the loading onto satisfactory ground. In clay soils subject to volume change on drying (‘shrinkable clays’, with Modified Plasticity Index greater than or equal to 10%), strip foundations should be taken to a depth where anticipated ground movements will not impair the stability of any part of the building taking due consideration of the influence of vegetation and trees on the ground. The depth to the underside of foundations on clay soils should be not less than 0.75m on low shrinkage clay soils, 0.9m on medium shrinkage clay soils and 1.0m on high shrinkage clay soils, although these depths may need to be increased in order to transfer the loading onto satisfactory ground, or where there are trees nearby.

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General

3.1Wall cladding presents a hazard if it becomes detached from the building. This section provides guidance on the support and fixing of wall cladding. An acceptable level of safety can be achieved by different means depending on the type and location of the cladding. The guidance given relates to all forms of cladding, including curtain walling and glass facades. It is not intended to provide guidance concerning the weather resistance of wall cladding which is included in Approved Document C, Site preparation and resistance to contaminants and moisture, or guidance on resistance to spread of fire which is included in Approved Document B, Fire safety, or guidance in relation to sound insulation, which is included in Approved Document E, Resistance to the passage of sound.

Technical approach

3.2The cladding will meet the safety requirement if:

a.the cladding is capable of safely sustaining and transmitting to the supporting structure of the building all dead, imposed and wind loads, and

b.the cladding is securely fixed to and supported by the structure of the building. This shall comprise both vertical support and horizontal restraint, and

c.provision is made, where necessary, to accommodate differential movement of the cladding and the supporting structure of the building, and

d.the cladding and its fixings (including any support components) are of durable materials; the design life of the fixings being not less than that of the cladding. Fixings shall be corrosion resistant and of a material type appropriate for the local environment.

Loading

3.3Wind loading on the cladding should be derived from BS EN 1991-1-4:2005 with its UK National Annex when due consideration given to local increases in wind suction arising from funnelling of the wind through gaps between buildings.

3.4Where the cladding is required to support other fixtures, e.g. handrails, and fittings, e.g. antennae and signboards, account should be taken of the loads and forces arising from such fixtures and fittings.

3.5Where the wall cladding is required to function as pedestrian guarding to stairs, ramps, vertical drops of more than 600mm in dwellings or more than the height of two risers (or 380mm if not part of a stair) in other buildings, or as a vehicle barrier, then account should be taken of the additional imposed loading, as stipulated in Approved Document K, Protection from falling, collision and impact.

3.6Where the wall cladding is required to safely withstand lateral pressures from crowds, an appropriate design loading is given in BS EN 1991-1-1:2002 with its UK National Annex and the Guide to Safety at Sports Grounds (4th Edition, 1997).

Fixings

3.7The selection of fixings for supporting cladding should be determined from a consideration of the proven performance of the fixing and the risks associated with the particular application. In this regard applications should be designated as being either non-redundant (where the failure of a single fixing could lead to the detachment of the cladding) or redundant (where failure or excessive movement of one fixing results in load sharing by adjacent fixings) and the required reliability of the fixing determined accordingly.

3.8The strength of fixings should be derived from tests using materials representative of the material into which the fixing is to be anchored, taking account of any inherent weaknesses that may affect the strength of the fixing, e.g. cracks in concrete due to shrinkage and flexure, or voids in masonry construction. The design loads will generally be available from the manufacturer’s test data determined from an ETA or an extant British Standard.

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3.9The use of large panels of glass in cladding of walls and roofs where the cladding is not divided into small areas by load-bearing framing requires special consideration. Guidance is given in the following documents:

The Institution of Structural Engineers’ Report on ‘Structural use of glass in buildings’ dated 1999, available from 11 Upper Belgrave Street, London SW1X 8BH.

‘Nickel sulfide in toughened glass’ published by the Centre for Window Cladding and Technology dated 2000.

3.10Further guidance on cladding is given in the following documents:

The Institution of Structural Engineers’ Report on ‘Aspects of Cladding’ dated 1995.

The Institution of Structural Engineers’ Report on ‘Guide to the structural use of adhesives’ dated 1999.

BS 8297:2000 Code of practice for the design and installation of non-load-bearing precast concrete cladding.

BS 8298:2010 Code of practice for the design and installation of natural stone cladding and lining.

3.11Additional guidance on fixings is given in the following documents:

ETAG No. 001 1997 Guideline for European Technical Approvals of Metal Anchors for use in Concrete, European Organisation for Technical Assessment (EOTA), Brussels. All EOTA parts may be downloaded in English from www.eota.be.

Part 1 Anchors in general.

Part 2 Torque controlled anchors.

Part 3 Undercut anchors.

Part 4 Deformation controlled anchors.

Part 5 Bonded anchors.

Part 6 Metal anchors for redundant use in concrete for lightweight systems.

BS 5080-1:1993 Structural fixings in concrete and masonry. Method of test for tensile loading.

CIRIA Report RP 566 Cladding Fixings: Good practice guidance.

CIRIA Reports C579 and C589 Retention of masonry facades – Best practice guide.

Guidance notes published by the Construction Fixings Association www.fixingscfa.co.uk.

Guidance Note: Procedure for Site Testing Construction Fixings (1994).

Guidance Note: European Technical Approvals for Construction Fixings (1998).

Guidance Note: Anchor Selection (1995).

Guidance Note: Fixings and Fire (1998).

Guidance Note: Anchor Installation (1996).

Guidance Note: Bonded Anchors (1999).

Guidance Note: Heavy Duty Expansion Anchors (1997).

Guidance Note: Fixings for Brickwork and Blockwork (1997).

Guidance Note: Undercut Anchors (1998).

Guidance Note: Fixings and Corrosion (2002).

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Materials

4.1All materials used to cover roofs, excluding windows of glass in residential buildings with roof pitches of not less than 15°, shall be capable of safely withstanding the concentrated imposed loads upon roofs specified in BS EN 1991-1-1:2002 with its UK National Annex. Transparent or translucent covering materials for roofs not accessible except for normal maintenance and repair are excluded from the requirement to carry the concentrated imposed load upon roofs if they are non-fragile or are otherwise suitably protected against collapse.

Re-covering of roofs

4.2The re-covering of roofs is commonly undertaken to extend the useful life of buildings. Roof structures may be required to carry underdrawing or insulation provided at a time later than their initial construction. This section provides guidance on determining whether such work to a roof constitutes a material alteration under the Building Regulations.

4.3Where the work involves a significant change in the applied loading the structural integrity of the roof structure and the supporting structure should be checked to ensure that upon completion of the work the building is not less compliant with Requirement A1 than the original building.

4.4A significant change in roof loading is when the loading upon the roof is increased by more than 15%. Consideration might also be given to whether the roof covering being replaced is the original as-built covering.

4.5Where such checking of the existing roof structure indicates that the construction is unable to sustain any proposed increase in loading (e.g. due to overstressed members or unacceptable deflection leading to ponding), appropriate strengthening work or replacement of roofing members should be undertaken. This is classified as a material alteration.

4.6In carrying out the checks mentioned in paragraph 4.3 an increase of stress in a structural member arising from increased loading does not necessarily indicate that the roof structure is less compliant than the original roof provided an adequate factor of safety is maintained.

4.7Where work will significantly decrease the roof dead loading, the roof structure and its anchorage to the supporting structure should be checked to ensure that an adequate factor of safety is maintained against uplift of the roof under imposed wind loading.

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This Approved Document deals with the following Requirements which are contained in the Building Regulations 2010.

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Performance

In the Secretary of State’s view the Requirement of A3 will be met by an appropriate choice of measures to reduce the sensitivity of a building to disproportionate collapse should an accident occur.

Introduction

0.1The guidance in Section 5 deals with the means of meeting this performance criterion.

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5.1The requirement will be met by adopting the following approach for ensuring that the building is sufficiently robust to sustain a limited extent of damage or failure, depending on the consequence class of the building, without collapse.

a.Determine the building’s consequence class from Table 11.

b.For Consequence Class 1 buildings – Provided the building has been designed and constructed in accordance with the rules given in this Approved Document, or other guidance referenced under Section 1, for meeting compliance with Requirement A1 and A2 in normal use, no additional measures are likely to be necessary.

c.For Consequence Class 2a buildings – In addition to the Consequence Class 1 measures, provide effective horizontal ties, or effective anchorage of suspended floors to walls, as described in the Standards listed under paragraph 5.2 for framed and load-bearing wall construction (the latter being defined in paragraph 5.3 below).

d.For Consequence Class 2b buildings – In addition to the Consequence Class 1 measures, provide effective horizontal ties, as described in the Standards listed under paragraph 5.2 for framed and load-bearing wall construction (the latter being defined in paragraph 5.3 below), together with effective vertical ties, as defined in the Standards listed under paragraph 5.2, 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 remains stable and that the area of floor at any storey at risk of collapse does not exceed 15% of the floor area of that storey or 100m², whichever is the smaller, and does not extend further than the immediate adjacent storeys (see Diagram 24).

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 a ‘key element’ as defined in paragraph 5.3 below.

e.For Consequence Class 3 buildings – A systematic risk assessment of the building should be undertaken taking into account all the normal hazards that may reasonably be foreseen, together with any abnormal hazards.

Critical situations for design should be selected that reflect the conditions that can reasonably be foreseen 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 given in the Standards given in paragraph 5.2.

Further guidance is given in Annexes A and B to BS EN 1991-1-7:2006 Eurocode 1: Actions on structures – Part 1.7: General actions – Accidental actions; with UK National Annex to BS EN 1991-1-7:2006 and BS EN 1990:2002+A1:2005 Eurocode – Basis of structural design; with UK National Annex to BS EN 1990:2002+A1:2005.

5.2Details of the effective horizontal and vertical ties including tie force determination, together with the design approaches for checking the integrity of the building following the notional removal of vertical members and the design of key elements, are given in the following Standards:

BS EN 1990:2002+A1:2005 Eurocode – Basis of structural design; with UK National Annex to BS EN 1990:2002+A1:2005

BS EN 1991-1-7:2006 Eurocode 1: Actions on structures – Part 1.7: General actions – Accidental actions; with UK National Annex to BS EN 1991-1-7: 2006 and BSI PD 6688-1-7: 2009

BS EN 1992-1-1:2004 Eurocode 2: Design of concrete structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1992-1-1:2004 and BSI PD 6687-1:2010

BS EN 1993-1-1:2005 Eurocode 3: Design of steel structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1993-1-1:2005

BS EN 1994-1-1:2004 Eurocode 4: Design of composite steel and concrete structures – Part 1.1: General rules for buildings; with UK National Annex to BS EN 1994-1-1:2004

BS EN 1995-1-1:2004+A1:2008 Eurocode 5: Design of timber structures – Part 1.1: General – Common rules and rules for buildings; with UK National Annex to BS EN 1995-1-1:2004+A1:2008 and BSI PD 6693-1:2012

BS EN 1996-1-1:2005+A1:2012 Eurocode 6: Design of masonry structures – Part 1.1: General rules for reinforced and unreinforced masonry structures; with UK National Annex to BS EN 1996-1-1:2005+A1:2012 and BSI PD 6697:2010

BS EN 1999-1-1:2007+A1:2009 Eurocode 9: Design of aluminium structures – Part 1.1: General structural rules; with UK National Annex to BS EN 1999-1-1:2007+A1:2009 and BSI PD 6702-1:2009

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BS EN 1999-1-1:2007+A1:2009 Eurocode 9: Design of aluminium structures – Part 1.1: General structural rules; with UK National Annex to BS EN 1999-1-1:2007+A1:2009 and BSI PD 6702-1:2009

5.3 Definitions

Nominal length of load-bearing wall

The nominal length of load-bearing wall construction referred to in 5.1d should be taken as follows:

–in the case of a reinforced concrete wall, the distance between lateral supports subject to a maximum length not exceeding 2.25H,

–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 exceeding 2.25H,

where H is the storey height in metres.

Note: Annex A of BS EN 1991-1-7:2006 with its UK National Annex provides corresponding guidance.

Key elements

A ‘key element’, as referred to in paragraph 5.1d, 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 (e.g. cladding etc.) having regard to the ultimate strength of such components and their connections. Such accidental design loading should be assumed to act simultaneously with all other design loadings (i.e. wind and imposed loading) in accidental actions loading combination.

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BS EN 1990:2002+A1:2005 with its UK National Annex provides guidance on accidental design loading and accidental actions loading combination for ‘key elements’ and expressions 6.11a and 6.11b of that Standard are relevant.

Load-bearing construction

For the purposes of this Guidance the term ‘load-bearing wall construction’ includes masonry cross-wall construction and walls comprising close centred timber or lightweight steel section studs.

Alternative approach

5.4As an alternative to Table 11, for any building which does not fall into the classes listed under Table 11, or for which the consequences of collapse may warrant particular examination of the risks involved, performance may be demonstrated using the recommendations given in the following Reports and Publication:

‘Guidance on Robustness and Provision against Accidental Actions’, dated July 1999.

‘Proposed Revised Guidance on meeting Compliance with the requirements of Building Regulation Part A3’. Revision of the Allott and Lomax proposals. Project Report No. 205966.

Both of the above documents are available on www.planningportal.gov.uk

‘Practical Guide to Structural Robustness and Disproportionate Collapse in Buildings’ dated October 2010. Published by The Institution of Structural Engineers, London.

Seismic design

5.5Seismic design is not usually required for buildings classified by Table 11 as being in Consequence Classes 1, 2a and 2b. For buildings classified as Consequence Class 3 the risk assessment should consider if there is any need to carry out seismic design, although such a need is not an explicit requirement for these buildings.

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A1/2

BS 5080-1:1993 Structural fixings in concrete and masonry. Method of test for tensile loading.

BS 8103-1:2011 Structural design of low-rise buildings. Code of practice for stability, site investigation, foundations, precast concrete floors and ground floor slabs for housing.

BS 8103-2:2005 Structural design of low-rise buildings. Code of practice for masonry walls for housing.

BS 8103-3:2009 Structural design of low-rise buildings. Code of practice for timber floors and roofs for housing.

BS 8297:2000 Code of practice for design and installation of non-loadbearing precast concrete cladding. AMD 11064 2000, AMD 13018 2000.

BS 8298-1:2010 Code of practice for the design and installation of natural stone cladding and lining. General.

BS 8298-2:2010 Code of practice for the design and installation of natural stone cladding and lining. Traditional handset external cladding.

BS 8298-3:2010 Code of practice for the design and installation of natural stone cladding and lining. Stone-faced pre-cast concrete cladding systems.

BS 8298-4:2010 Code of practice for the design and installation of natural stone cladding and lining. Rainscreen and stone on metal frame cladding systems.

BS 8500-1:2006+A1:2012 Concrete. Complementary British Standard to BS EN 206-1. Method of specifying and guidance for the specifier.

BS 8500-2:2006+A1:2012 Concrete. Complementary British Standard to BS EN 206-1. Specification for constituent materials and concrete.

BS EN 197-1:2011 Cement. Composition, specifications and conformity criteria for common elements.

BS EN 197-2:2000 Cement. Conformity evaluation.

BS EN 771-1:2011 Specification for masonry units. Clay masonry units.

BS EN 771-2:2011 Specification for masonry units. Calcium silicate masonry units.

BS EN 771-3:2011 Specification for masonry units. Aggregate concrete masonry units (dense and light-weight aggregates). AMD 16001.

BS EN 771-4:2011 Specification for masonry units. Autoclaved aerated concrete masonry units.

BS EN 771-5:2011 Specification for masonry units. Manufactured stone masonry units.

BS EN 771-6:2011 Specification for masonry units. Natural stone masonry units.

BS EN 845-1:2003+A1:2008 Specification for ancillary components for masonry. Ties, tension straps, hangers and brackets. AMD 14736 2003, AMD 15539 2006.

BS EN 845-2:2003 Specification for ancillary components for masonry. Lintels.

BS EN 845-3:2003+A1:2008 Specification for ancillary components for masonry. Bed joint reinforcement of steel meshwork.

BS EN 998-2:2010 Specification for mortar for masonry. Masonry mortar. AMD July 2011.

BS EN 1090-2:2008+A1:2011 Execution of steel structures and aluminium structures – Part 2: Technical requirements for the execution of steel structures.

BS EN 1090-3:2008 Execution of steel structures and aluminium structures – Part 3: Technical requirements for aluminium structures.

BS EN 1990:2002+A1:2005 Eurocode – Basis of structural design; with UK National Annex to BS EN 1990:2002+A1:2005.

BS EN 1991-1-1:2002 Eurocode 1: Actions on structures – Part 1.1: General actions – Densities, self weight, imposed loads for buildings; with UK National Annex to BS EN 1991-1-1:2002.

BS EN 1991-1-3:2003 Eurocode 1: Actions on structures – Part 1.3: General actions – Snow loads; with UK National Annex to BS EN 1991-1-3:2003.

BS EN 1991-1-4:2005+A1:2010 Eurocode 1: Actions on structures – Part 1.4: General actions – Wind actions; with UK National Annex to BS EN 1991-1-4:2005+A1:2010.

BS EN 1991-1-5:2003 Eurocode 1: Actions on structures – Part 1.5: General actions – Thermal actions; with UK National Annex to BS EN 1991-1-5:2003.

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BS EN 1991-1-6:2005 Eurocode 1: Actions on structures – Part 1.6: General actions – Actions during execution; with UK National Annex to BS EN 1996-1-6:2005.

BS EN 1991-1-7:2006 Eurocode 1: Actions on structures – Part 1.7: General actions – Accidental actions; with UK National Annex to BS EN 1991-1-7:2006.

BS EN 1991-3:2006 Eurocode 1: Actions on structures – Part 3: Actions induced by cranes and machinery; with UK National Annex to BS EN 1991-3:2006.

BS EN 1992-1-1:2004 Eurocode 2: Design of concrete structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1992-1-1:2004.

BS EN 1993-1-1:2005 Eurocode 3: Design of steel structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1993-1-1:2005.

BS EN 1993-1-3:2006 Eurocode 3: Design of steel structures – Part 1.3: General rules – Supplementary rules for cold-formed members and sheeting; with UK National Annex to BS EN 1993-1-3:2006.

BS EN 1993-1-4:2006 Eurocode 3: Design of steel structures – Part 1.4: General rules – Supplementary rules for stainless steels; with UK National Annex to BS EN 1993-1-4:2006.

BS EN 1993-1-5:2006 Eurocode 3: Design of steel structures – Part 1.5: Plated structural elements; with UK National Annex to BS EN 1993-1-5:2006.

BS EN 1993-1-6:2007 Eurocode 3: Design of steel structures – Part 1.6: Strength and stability of shell structures.

BS EN 1993-1-7:2007 Eurocode 3: Design of steel structures – Part 1.7: Plated structures subject to out of plane loading.

BS EN 1993-1-8:2005 Eurocode 3: Design of steel structures – Part 1.8: Design of joints; with UK National Annex to BS EN 1993-1-8:2005.

BS EN 1993-1-9:2005 Eurocode 3: Design of steel structures – Part 1.9: Fatigue; with UK National Annex to BS EN 1993-1-9:2005.

BS EN 1993-1-10:2005 Eurocode 3: Design of steel structures – Part 1.10: Material toughness and through-thickness properties; with UK National Annex to BS EN 1993-1-10:2005.

BS EN 1993-1-11:2006 Eurocode 3: Design of steel structures – Part 1.11: Design of structures with tension components; with UK National Annex to BS EN 1993-1-11:2006.

BS EN 1993-1-12:2007 Eurocode 3: Design of steel structures – Part 1.12: Additional rules for the extension of EN 1993 up to steel grades S 700; with UK National Annex to BS EN 1993-1-12:2007.

BS EN 1993-5:2007 Eurocode 3: Design of steel structures – Part 5: Piling; with UK National Annex to BS EN 1993-5:2007+A1:2012.

BS EN 1993-6:2007 Eurocode 3: Design of steel structures – Part 6: Crane supporting structures; with UK National Annex to BS EN 1993-6:2007.

BS EN 1994-1-1:2004 Eurocode 4: Design of composite steel and concrete structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1994-1-1:2004.

BS EN 1995-1-1:2004+A1:2008 Eurocode 5: Design of timber structures – Part 1.1: General – Common rules and rules for buildings; with UK National Annex to BS EN 1995-1-1:2004+A1:2008.

BS EN 1996-1-1:2005+A1:2012 Eurocode 6: Design of masonry structures – Part 1.1: General rules for reinforced and unreinforced masonry structures; with UK National Annex to BS EN 1996-1-1:2005+A1:2012.

BS EN 1996-2:2006 Eurocode 6: Design of masonry structures – Part 2: Design considerations, selection of materials and execution of masonry; with UK National Annex to BS EN 1996-2:2006.

BS EN 1996-3:2006 Eurocode 6: Design of masonry structures – Part 3: Simplified calculation methods for unreinforced masonry structures; with UK National Annex to BS EN 1996-3:2006.

BS EN 1997-1:2004 Eurocode 7: Geotechnical design – Part 1: General rules; with UK National Annex to BS EN 1997-1:2004.

BS EN 1997-2:2007 Eurocode 7: Geotechnical design – Part 2: Ground investigation and testing; with UK National Annex to BS EN 1997-2:2007.

BS EN 1998-1:2004+A1:2013 Eurocode 8: Design of structures for earthquake resistance – Part 1: General rules, seismic actions and rules for buildings; with UK National Annex to BS EN 1998-1:2004.

BS EN 1998-5:2004 Eurocode 8: Design of structures for earthquake resistance – Part 5. Foundations, retaining structures and geotechnical aspects; with UK National Annex to BS EN 1998-5:2004.

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BS EN 1999-1-1:2007+A1:2009 Eurocode 9: Design of aluminium structures – Part 1.1: General structural rules; with UK National Annex to BS EN 1999-1-1:2007+A1:2009.

BS EN 1999-1-3:2007+A1:2011 Eurocode 9: Design of aluminium structures – Part 1.3: Structures susceptible to fatigue; with UK National Annex to BS EN 1999-1-3:2007+A1:2011.

BS EN 1999-1-4:2007+A1:2011 Eurocode 9: Design of aluminium structures – Part 1.4: Cold-formed structural sheeting; with UK National Annex to BS EN 1999-1-4:2007.

BS EN 1999-1-5:2007 Eurocode 9: Design of aluminium structures – Part 1.5: Shell structures; with UK National Annex to BS EN 1999-1-5:2007.

BS EN 12620:2002+A1:2008 Aggregates for concrete. AMD 15333 2004.

BS EN 13670:2009 Execution of concrete structures.

BSI PD 6687-1:2010 Published Document – Background paper to the UK National Annexes to BS EN 1992-1 and BS EN 1992-3.

BSI PD 6688-1-1:2011 Published Document – Recommendations for the design of structures to BS EN 1991-1-1.

BSI PD 6688-1-4:2009 Published Document – Background information the National Annex to BS EN 1991-1-4 and additional guidance.

BSI PD 6688-1-7:2009 Published Document – Recommendations for the design of structures to BS EN 1991-1-7.

BSI PD 6693-1:2012 Published Document – Recommendations for the design of timber structures to Eurocode 5: Design of timber structures Part 1: General – Common rules and rules for buildings.

BSI PD 6695-1-9:2008 Published Document – Recommendations for the design of structures to BS EN 1993-1-9.

BSI PD 6695-1-10:2009 Published Document – Recommendations for the design of structures to BS EN 1993-1-10.

BSI PD 6697:2010 Published Document – Recommendations for the design of masonry structures to BS EN 1996-1-1 and BS EN 1996-2.

BSI PD 6698:2009 Published Document – Recommendations for the design of structures for earthquake resistance to BS EN 1998.

BSI PD 6702-1:2009 Published Document – Structural use of aluminium – Part 1: Recommendations for the design of aluminium structures to BS EN 1999.

BSI PD 6705-3:2009 Published Document – Structural use of steel and aluminium – Part 3: Recommendations for the execution of aluminium structures to BS EN 1090-3.

A3

BS EN 1990:2002+A1:2005 Eurocode – Basis of structural design; with UK National Annex to BS EN 1990:2002+A1:2005.

BS EN 1991-1-7:2006 Eurocode 1: Actions on structures – Part 1.7: General actions – Accidental actions; with UK National Annex to BS EN 1991-1-7:2006.

BS EN 1992-1-1:2004 Eurocode 2: Design of concrete structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1992-1-1:2004.

BS EN 1993-1-1:2005 Eurocode 3: Design of steel structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1993-1-1:2005.

BS EN 1994-1-1:2004 Eurocode 4: Design of composite steel and concrete structures – Part 1.1: General rules and rules for buildings; with UK National Annex to BS EN 1994-1-1:2004.

BS EN 1995-1-1:2004+A1:2008 Eurocode 5: Design of timber structures – Part 1.1: General – Common rules and rules for buildings; with UK National Annex to BS EN 1995-1-1:2004+A1:2008.

BS EN 1996-1-1:2005+A1:2012 Eurocode 6: Design of masonry structures – Part 1.1: General rules for reinforced and unreinforced masonry structures; with UK National Annex to BS EN 1996-1-1:2005+A1:2012.

BS EN 1999-1-1:2007+A1:2009 Eurocode 9: Design of aluminium structures – Part 1.1: General structural rules; with UK National Annex to BS EN 1999-1-1:2007+A1:2009.

BSI PD 6687-1:2010 Published Document – Background paper to the UK National Annexes to BS EN 1992-1 and BS EN 1992-3.

BSI PD 6688-1-7:2009 Published Document – Recommendations for the design of structures to BS EN 1991-1-7.

BSI PD 6693-1:2012 Published Document – Recommendations for the design of timber structures to Eurocode 5: Design of timber structures Part 1: General – Common rules and rules for buildings.

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BSI PD 6697:2010 Published Document – Recommendations for the design of masonry structures to BS EN 1996-1-1 and BS EN 1996-2.

BSI PD 6702-1:2009 Published Document – Structural use of aluminium – Part 1. Recommendations for the design of aluminium structures to BS EN 1999.

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Fire safety

APPROVED DOCUMENT B

Volume 1: Dwellings

Requirement B1: Means of warning and escape

Requirement B2: Internal fire spread (linings)

Requirement B3: Internal fire spread (structure)

Requirement B4: External fire spread

Requirement B5: Access and facilities for the fire service

Regulations: 6(3), 7(2) and 38

2019 edition incorporating 2020 and 2022 amendments – for use in England

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The changes focus on the following fire safety provisions in blocks of flats:

a.Sprinklers: A reduction in the trigger height from 30m to 11m.

b.Wayfinding signage for the fire service: A new recommendation for floor identification and flat indication signage within blocks of flats with storeys over 11m.

In addition a typographical error is corrected in both volumes. Purpose group number 2 is now included in reference to ‘residential’ buildings in the guidance on boundaries.

The changes are set out in the May 2020 AD B amendments.

Main changes made by the 2022 amendments

The changes focus on the following fire safety provisions:

a.Ban of combustible materials in and on the external walls of buildings: Consequential amendments following the laying of the Building (Amendment) (England) Regulations 2022. Updated provisions in Section 10 for residential buildings (purpose groups 1 and 2) with a storey 11m or more in height.

b.Secure information boxes: A new recommendation for secure information boxes in blocks of flats with storeys over 11m.

c.Evacuation alert systems: A new recommendation for evacuation alert systems in blocks of flats with storeys over 18m.

d.Clarifications and corrections: Clarification of further diagrams, further text clarifications and corrections.

The changes are set out in the June 2022 AD B amendment booklet and November 2022 correction notice.

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What is an approved document?

Approved documents are approved by the Secretary of State and give practical guidance on common building situations about how to meet the requirements of the Building Regulations 2010 for England. Different approved documents give guidance on each of the technical parts of the regulations. These are all listed in the back of the approved documents. In addition to guidance, some approved documents include provisions that must be followed exactly, as required by regulations or where methods of test or calculation are approved by the Secretary of State.

Each approved document covers the requirements of the Building Regulations 2010 relating to a different aspect of building work. Building work must also comply with all other applicable requirements of the Building Regulations 2010 and all other applicable legislation.

How is construction regulated in England?

Most building work being carried out in England must comply with the Building Regulations 2010. The Building Regulations are made under powers in the Building Act 1984.

Building Regulations protect the health and safety of people in and around buildings, they also provide for energy and water conservation and access to and use of buildings.

The Manual to the Building Regulations (references to this in the introduction are taken from the first edition) gives an overview of the building regulatory system in England. You can access the most recent version of the manual at: www.gov.uk/guidance/building-regulations-and-approved-documents-index.

How do you comply with the Building Regulations?

Building work must meet all relevant requirements of the Building Regulations. To comply with the Building Regulations, it is necessary both to follow the correct procedures and meet technical performance requirements.

The approved documents set out what, in ordinary circumstances, may be accepted as one way to comply with the Building Regulations. Note, however, that:

•Complying with the guidance in the approved documents does not guarantee that building work complies with the requirements of the regulations – the approved documents cannot cover all circumstances. Those responsible for building work must consider whether following the guidance in the approved documents is likely to meet the requirements in the particular circumstances of their case.

•There may be other ways to comply with the requirements than those described in an approved document. If those responsible for meeting the requirements prefer to meet a requirement in some other way than described in an approved document, they should seek to agree this with the relevant building control body at an early stage.

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Those responsible for building work include agents, designers, builders, installers and the building owner. For further information, see Chapter 7 in Volume 1 and paragraphs A26, B2 and F2 in Volume 2 of the Manual to the Building Regulations.

The Building Regulations can be contravened by not following the correct procedures or not meeting the technical performance requirements. If the building owner or those responsible for the works contravene the Building Regulations, the local authority may prosecute them in the magistrates’ court. For further information on enforcement and sanctions in the existing system, see Chapter B in Volume 2 of the Manual to the Building Regulations.

What do the Building Regulations cover?

‘Building work’ is a legal term for work covered by the Building Regulations. Where a building is not exempt, the Building Regulations apply to all types of building work as defined in regulation 3 of the Building Regulations. For further information, what constitutes building work is covered in Chapter A, Volume 2 of the Manual to the Building Regulations.

The Building Regulations contain sections dealing with definitions, procedures and the expected technical performance of building work. For example, the Building Regulations:

a.define what types of building, plumbing and heating work are classed as building work in regulation 3 (for further information see paragraphs A14 to A16 in Volume 2 of the Manual to the Building Regulations).

b.specify types of building that are exempt from the Building Regulations (for further information see Table A1 and paragraph A11 in Volume 2 of the Manual to the Building Regulations).

c.set out the notification procedures to follow when undertaking building work (for further information see Figure 2.1 in Volume 1 of the Manual to the Building Regulations).

d.set out the technical requirements (see Table 7.1 in Volume 1 of the Manual to the Building Regulations) with which the individual aspects of building design and construction must comply in the interests of the health and safety of building users, of energy efficiency (for further information see paragraphs A12(d)–(f), A14(f)–(h), A22, A23, B2(c) and F24 in Volume 2 of the Manual to the Building Regulations), and of access to and use of buildings.

e.set out the standards for building materials and workmanship in carrying out building work (for further information see Chapter 7 in Volume 1, and paragraphs F8 to F11 in Volume 2 of the Manual to the Building Regulations).

When must a building control body be notified?

It is often necessary to notify a building control body of planned building work. To help ensure that work complies with the Building Regulations, those responsible for building work may need to use one of the two types of building control body listed below:

a.a local authority building control body (for further information see Chapter B in Volume 2 of the Manual to the Building Regulations)

b.an approved inspector (for further information see Chapter E in Volume 2 of the Manual to the Building Regulations).

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If building work consists only of installing certain types of services or fittings (e.g. fuel-burning appliances or replacement windows) and the building owner employs an installer that is registered with a relevant competent person scheme designated in the regulations, a building control body does not need to be notified.

Third party schemes of certification and accreditation of installers can provide confidence that the required level of performance for a system, product, component or structure can be achieved. Building control bodies may accept certification under such schemes as evidence of compliance with a relevant standard. However, a building control body should establish before the start of the building work that a scheme is adequate for the purposes of the Building Regulations.

For further information about third party certification schemes and competent person schemes, see Chapter 5 in Volume 1 and Chapter C in Volume 2 of the Manual to the Building Regulations.

How to use this approved document

Each approved document contains:

•general guidance on the performance expected of materials and building work in order to comply with each of the requirements of the Building Regulations, and

•practical examples and solutions on how to achieve compliance for some of the more common building situations.

They may not provide appropriate guidance if the case is unusual in terms of its design, setting, use, scale or technology. Non-standard conditions may include any of the following:

•difficult ground conditions

•buildings with unusual occupancies or high levels of complexity

•very large or very tall buildings

•large timber buildings

•some buildings that incorporate modern construction methods.

Anyone using the approved documents should have sufficient knowledge and skills to understand the guidance and correctly apply it to the building work. This is important because simply following the guidance does not guarantee that your building work will comply with the legal requirements of the Building Regulations. Each approved document contains legal requirements (which you must follow) and guidance (which you may or may not choose to follow). The text in a box with a green background at the beginning of each section of an approved document is taken from the Building Regulations. This text sets out the legal requirements.

The explanation which follows the legal requirements is guidance (see Diagram i below). The guidance then explains one or more ways to demonstrate how building work can be shown to comply with the legal requirements in common circumstances. The terms in green lettering in an approved document are key terms, listed and explained in the appendix to that approved document. Guidance in the approved documents addresses most, but not all, situations that building owners will face. Situations may arise that are not covered. You or your advisers will need to carefully consider whether following the guidance will mean that the requirements of the Building Regulations will be met.

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This section deals with the following requirement from Part B of Schedule 1 to the Building Regulations 2010.

Intention

In the Secretary of State’s view, requirement B2 is met by achieving a restricted spread of flame over internal linings. The building fabric should make a limited contribution to fire growth, including a low rate of heat release.

It is particularly important in circulation spaces, where linings may offer the main means by which fire spreads and where rapid spread is most likely to prevent occupants from escaping.

Requirement B2 does not include guidance on the following.

a.Generation of smoke and fumes.

b.The upper surfaces of floors and stairs.

c.Furniture and fittings.

Key

➊ The law: extract from the Building Regulations 2010.

➋ Statutory guidance.

For further information about the use of technical guidance, see Chapter 7 in Volume 1 and Chapter F in Volume 2 of the Manual to the Building Regulations.

Where to get further help

If you are unsure whether you have the knowledge and skills to apply the guidance correctly, or if you do not understand the technical guidance or other information in this approved document or the additional detailed technical references to which it directs you, you should seek further help. Some sources of help are listed below.

a.Your building control body may be able to help in many cases.

b.If you are registered with a competent person scheme, the scheme operator should be in a position to help.

c.Suitably qualified and experienced construction professionals should also be engaged where necessary.

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Introduction

What is an approved document? i

How is construction regulated in England? i

How do you comply with the Building Regulations? i

What do the Building Regulations cover? ii

When must a building control body be notified? ii

How to use this approved document iii

Where to get further help iv

Section 0: Approved Document B: Fire safety – dwellings 1

Summary 1

Arrangement of sections 1

Management of premises 2

Property protection 2

Inclusive design 2

Alternative approaches 3

Purpose groups 4

Mixed use buildings 7

Requirement B1: Means of warning and escape 8

Intention 8

Section 1: Fire detection and alarm systems 9

General provisions 9

Large dwellinghouses 9

Extensions and material alterations 9

Blocks of flats 10

Student accommodation 10

Sheltered housing 10

Design and installation of systems 10

Section 2: Means of escape – dwellinghouses 11

Escape from the ground storey 11

Escape from upper storeys a maximum of 4.5m above ground level 11

Escape from upper storeys more than 4.5m above ground level 11

General provisions 15

Work on existing dwellinghouses 18

Section 3: Means of escape – flats 19

Introduction 19

General provisions 19

Flats with upper storeys a maximum of 4.5m above ground level 21

Flats with storeys more than 4.5m above ground level 22

Means of escape in the common parts of flats 26

Common stairs 33

Doors on escape routes 38

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Lifts 40

Final exits 41

Requirement B2: Internal fire spread (linings) 42

Intention 42

Section 4: Wall and ceiling linings 43

Classification of linings 43

Thermoplastic materials 45

Requirement B3: Internal fire spread (structure) 49

Intention 49

Section 5: Internal fire spread – dwellinghouses 50

Loadbearing elements of structure 50

Compartmentation 51

Cavities 54

Section 6: Loadbearing elements of structure – flats 57

Fire resistance standard 57

Conversion to flats 58

Section 7: Compartmentation/sprinklers – flats 59

Provision of compartmentation 59

Sprinklers 59

Construction of compartment walls and compartment floors 59

Openings in compartmentation 61

Protected shafts 61

Section 8: Cavities – flats 65

Provision of cavity barriers 65

Pathways around fire-separating elements 65

Construction and fixings for cavity barriers 68

Section 9: Protection of openings and fire-stopping 69

Introduction 69

Openings for pipes 69

Mechanical ventilation and air-conditioning systems 71

Flues, etc. 74

Fire-stopping 75

Requirement B4: External fire spread 76

Intention 78

Section 10: Resisting fire spread over external walls 79

Introduction 79

Combustibility of external walls 79

Balconies 81

Metal composite materials 82

Regulation 7(2) and requirement B4 82

Section 11: Resisting fire spread from one building to another 84

Introduction 84

Boundaries 84

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Unprotected areas and fire resistance

Methods for calculating acceptable unprotected area

Section 12: Resisting fire spread over roof coverings

Introduction

Separation distances

Requirement B5: Access and facilities for the fire service

Intention

Section 13: Vehicle access

Provision and design of access routes and hardstandings

Blocks of flats fitted with fire mains

Section 14: Fire mains and hydrants – flats

Introduction

Provision of fire mains

Design and construction of fire mains

Provision of private hydrants

Section 15: Access to buildings for firefighting personnel – flats

Provision of firefighting shafts

Design and construction of firefighting shafts

Rolling shutters in compartment walls

Wayfinding signage for the fire service

Section 16: Venting of heat and smoke from basements – flats

Provision of smoke outlets

Construction of outlet ducts or shafts

Regulation 38: Fire safety information

Intention

Section 17: Fire safety information

Essential information

Additional information for complex buildings

Appendix A: Key terms

Appendix B: Performance of materials, products and structures

Introduction

Reaction to fire

National classifications for reaction to fire

Thermoplastic materials

Roofs

Fire resistance

Application of the fire resistance standards in Table B4

Appendix C: Fire doorsets

Appendix D: Methods of measurement

Occupant number

Travel distance

Width

Building dimensions

Free area of smoke ventilators

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Sprinkler systems

Design of sprinkler systems

Water supplies and pumps

Appendix F: Standards referred to

European Standards

British Standards

Appendix G: Documents referred to

Legislation

Other documents

Section 17: Fire safety information

Essential information

Additional information for complex buildings

Appendix A: Key terms

Appendix B: Performance of materials, products and structures

Introduction

Reaction to fire

National classifications for reaction to fire

Thermoplastic materials

Roofs

Fire resistance

Application of the fire resistance standards in Table B4

Appendix C: Fire doorsets

Appendix D: Methods of measurement

Occupant number

Travel distance

Width

Building dimensions

Free area of smoke ventilators

Appendix E: Sprinklers

Sprinkler systems

Design of sprinkler systems

Water supplies and pumps

Appendix F: Standards referred to

European Standards

British Standards

Appendix G: Documents referred to

Legislation

Other documents

Index

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Summary

0.1This approved document has been published in two volumes. Volume 1 deals solely with dwellings, including blocks of flats, while Volume 2 deals with all other types of building covered by the Building Regulations.

Arrangement of sections

0.2Requirements B1–B5 of Schedule 1 to the Building Regulations are dealt with separately in one or more sections. Each requirement is shown at the start of the relevant sections.

0.3The provisions in this document have the following aims.

Requirement B1: When there is a fire, ensure both:

a.satisfactory means of sounding an alarm

b.satisfactory means of escape for people.

Requirement B2: Inhibit the spread of fire over internal linings of buildings.

Requirement B3: The building must be built such that all of the following are achieved in the event of a fire:

a.the premature collapse of the building is avoided

b.sufficient fire separation is provided within buildings and between adjoining buildings

c.automatic fire suppression is provided where necessary

d.the unseen spread of fire and smoke in cavities is restricted.

Requirement B4: Restrict both:

a.the potential for fire to spread over external walls and roofs (including compliance with regulations 6(4) and 7(2))

b.the spread of fire from one building to another.

Requirement B5: Ensure both:

a.satisfactory access for the fire service and its appliances

b.facilities in buildings to help firefighters save the lives of people in and around buildings.

Regulation 38: Provide fire safety information to building owners.

0.4Guidance is given on each aspect separately, though many are closely interlinked. The document should be considered as a whole. The relationship between different requirements and their interdependency should be recognised. Particular attention should be given to the situation where one part of the guidance is not fully followed, as this could have a negative effect on other provisions.

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0.5Guidance on matters that refer to more than one section of this document can be found in the following appendices.

•Appendix A: Key terms

•Appendix B: Performance of materials, products and structures

•Appendix C: Fire doorsets

•Appendix D: Methods of measurement

•Appendix E: Sprinklers

•Appendix F: Standards referred to

•Appendix G: Documents referred to

Management of premises

0.6The Building Regulations do not impose any requirements on the management of a building, but do assume that it will be properly managed. This includes, for example, keeping protected escape routes virtually ‘fire sterile’.

Appropriate fire safety design considers the way in which a building will be managed. Any reliance on an unrealistic or unsustainable management regime cannot be considered to have met the requirements of the regulations.

Once the building is in use, the management regime should be maintained and a suitable risk assessment undertaken for any variation in that regime. Failure to take proper management responsibility may result in the prosecution of an employer, building owner or occupier under legislation such as the Regulatory Reform (Fire Safety) Order 2005.

Property protection

0.7The Building Regulations are intended to ensure a reasonable standard of life safety in a fire. The protection of property, including the building itself, often requires additional measures. Insurers usually set higher standards before accepting the insurance risk.

Many insurers use the RISCAuthority Design Guide for the Fire Protection of Buildings by the Fire Protection Association (FPA) as a basis for providing guidance to the building designer on what they require.

Further information on the protection of property can be obtained from the FPA website: www.thefpa.co.uk.

Inclusive design

0.8The fire safety aspects of the Building Regulations aim to achieve reasonable standards of health and safety for people in and around buildings.

People, regardless of ability, age or gender, should be able to access buildings and use their facilities. The fire safety measures incorporated into a building should take account of the needs of everyone who may access the building, both as visitors and as people who live or work in it. It is not appropriate, except in exceptional circumstances, to assume that certain groups of people will be excluded from a building because of its use.

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The provisions in this approved document are considered to be of a reasonable standard for most buildings. However, some people’s specific needs might not be addressed. In some situations, additional measures may be needed to accommodate these needs. This should be done on a case-by-case basis.

Alternative approaches

0.9The fire safety requirements of the Building Regulations will probably be satisfied by following the relevant guidance in this approved document. However, approved documents provide guidance for some common building situations, and there may be alternative methods of complying with the Building Regulation requirements.

If alternative methods are adopted, the overall level of safety should not be lower than the approved document provides. It is the responsibility of those undertaking the work to demonstrate compliance.

If other standards or guidance documents are adopted, the relevant fire safety recommendations in those publications should be followed in their entirety. However, in some circumstances it may be necessary to use one publication to supplement another. Care must be taken when using supplementary guidance to ensure that an integrated approach is used in any one building.

Guidance documents intended specifically for assessing fire safety in existing buildings often include less onerous provisions than those for new buildings and are therefore unlikely to be appropriate for building work that is controlled by the Building Regulations.

Buildings for industrial and commercial activities that present a special fire hazard, e.g. those that sell fuels, may require additional fire precautions to those in this approved document.

Buildings of special architectural or historic interest

0.10Where Part B applies to existing buildings, particularly buildings of special architectural or historic interest for which the guidance in this document might prove too restrictive, some variation of the provisions in this document may be appropriate. In such cases, it is appropriate to assess the hazard and risk in the particular case and consider a range of fire safety features in that context.

Sheltered housing

0.11While many of the provisions in this approved document for means of escape from flats are applicable to sheltered housing, the nature of the occupancy may necessitate some additional fire protection measures. The extent of such measures will depend on the form of the development. For example, a group of specially adapted bungalows or two storey flats, with few communal facilities, will not need to be treated differently from other single storey or two storey dwellinghouses or flats.

Fire safety engineering

0.12Fire safety engineering might provide an alternative approach to fire safety. Fire safety engineering may be the only practical way to achieve a satisfactory standard of fire safety in some complex buildings and in buildings that contain different uses.

Fire safety engineering may also be suitable for solving a specific problem with a design that otherwise follows the provisions in this document.

0.13BS 7974 and supporting published documents (PDs) provide a framework for and guidance on the application of fire safety engineering principles to the design of buildings.

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0.14Building uses are classified within different purpose groups, which represent different levels of hazard (see Table 0.1). A purpose group can apply to a whole building or a compartment within the building, and should relate to the main use of the building or compartment.

0.15Where a building or compartment has more than one use, it is appropriate to assign each different use to its own purpose group in the following situations.

a.If the ancillary use is a flat.

b.If both of the following apply.

i.The building or compartment has an area of more than 280m².

ii.The ancillary use relates to an area that is more than one-fifth of the total floor area of the building or compartment.

c.In ‘shop and commercial’ (purpose group 4) buildings or compartments, if the ancillary use is storage and both of the following apply.

i.The building or compartment has an area of more than 280m².

ii.The storage area comprises more than one-third of the total floor area of the building or compartment.

0.16Where there are multiple main uses that are not ancillary to one another (for example, shops with independent offices above), each use should be assigned to a purpose group in its own right. Where there is doubt as to which purpose group is appropriate, the more onerous guidance should be applied.

0.17In sheltered housing, the guidance in Approved Document B Volume 2 should be consulted for the design of communal facilities, such as a common lounge.

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0.18This approved document includes reference to selected guidance for buildings other than dwellings. For the design of mixed use buildings, Approved Document B Volume 2 should be consulted in addition to the guidance contained in this approved document.

0.19Where a complex mix of uses exists, the effect that one use may have on another in terms of risk should be considered. It could be necessary to use guidance from both volumes, apply other guidance (such as from HTM 05-02 or Building Bulletin 100), and/or apply special measures to reduce the risk.

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These sections deal with the following requirement from Part B of Schedule 1 to the Building Regulations 2010.

Intention

In the Secretary of State’s view, requirement B1 is met by achieving all of the following.

a.There are sufficient means for giving early warning of fire to people in the building.

b.All people can escape to a place of safety without external assistance.

c.Escape routes are suitably located, sufficient in number and of adequate capacity.

d.Where necessary, escape routes are sufficiently protected from the effects of fire and smoke.

e.Escape routes are adequately lit and exits are suitably signed.

f.There are appropriate provisions to limit the ingress of smoke to the escape routes, or to restrict the spread of fire and remove smoke.

g.For buildings containing flats, there are appropriate provisions to support a stay put evacuation strategy.

The extent to which any of these measures are necessary is dependent on the use of the building, its size and its height.

Building work and material changes of use subject to requirement B1 include both new and existing buildings.

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General provisions

1.1All dwellings should have a fire detection and alarm system, minimum Grade D2 Category LD3 standard, in accordance with the relevant recommendations of BS 5839-6.

A higher standard of protection should be considered where occupants of a proposed dwelling would be at special risk from fire. Further advice on this is also given in BS 5839-6.

1.2Smoke alarms should be mains operated and conform to BS EN 14604.

1.3Heat alarms should be mains operated and conform to BS 5446-2.

1.4Smoke and heat alarms should have a standby power supply, such as a battery (rechargeable or non-rechargeable) or capacitor. More information on power supplies is given in clause 15 of BS 5839-6.

Large dwellings

1.5A large dwellinghouse has more than one storey, and at least one storey exceeds 200m².

1.6A large dwellinghouse of two storeys (excluding basement storeys) should be fitted with a Grade A Category LD3 fire detection and alarm system, as described in BS 5839-6.

1.7A large dwellinghouse of three or more storeys (excluding basement storeys) should be fitted with a Grade A Category LD2 fire detection and alarm system as described in BS 5839-6.

Extensions and material alterations

1.8A fire detection and alarm system should be installed where either of the following applies.

a.A new habitable room is provided above or below the ground storey.

b.A new habitable room is provided at the ground storey, without a final exit.

1.9Smoke alarms should be provided in the circulation spaces of the dwelling in accordance with paragraphs 1.1 to 1.4.

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1.10Each flat in a block should have alarms as set out in paragraphs 1.1 to 1.4. With effective compartmentation, a communal fire alarm system is not normally needed. In some buildings, detectors in common parts of the building may need to operate smoke control or other fire protection systems but do not usually sound an audible warning.

Student accommodation

1.11In student residences that are designed and occupied as a block of flats, separate automatic detection should be provided in each self-contained flat where all of the following apply.

a.A group of up to six students shares the flat.

b.Each flat has its own entrance door.

c.The compartmentation principles for flats in Section 7 have been followed.

Where a total evacuation strategy is adopted, the alarm system should follow the guidance for buildings other than dwellings in Volume 2 of Approved Document B.

Sheltered housing

1.12The fire detection and alarm systems in flats should connect to a central monitoring point or alarm receiving centre. The systems should alert the warden or supervisor and identify the individual flat where a fire has been detected.

1.13These provisions do not apply to the following.

a.The common parts of a sheltered housing development, such as communal lounges.

b.Sheltered accommodation in the 'residential (institutional)' or 'residential (other)' purpose groups (purpose group 2(a) or 2(b)).

In these parts, means of warning should follow the guidance for buildings other than dwellings in Volume 2 of Approved Document B.

Design and installation of systems

1.14Fire detection and alarm systems must be properly designed, installed and maintained. A design, installation and commissioning certificate should be provided for fire detection and alarm systems. Third party certification schemes for fire protection products and related services are an effective means of providing assurances of quality, reliability and safety.

Interface between fire detection and alarm systems and other systems

1.15Fire detection and alarm systems sometimes trigger other systems. The interface between systems must be reliable. Particular care should be taken if the interface is facilitated via another system. Where any part of BS 7273 applies to the triggering of other systems, the recommendations of that part of BS 7273 should be followed.

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Escape from the ground storey

2.1See Diagram 2.1a. All habitable rooms (excluding kitchens) should have either of the following.

a.An opening directly onto a hall leading to a final exit.

b.An emergency escape window or door, as described in paragraph 2.10.

Escape from upper storeys a maximum of 4.5m above ground level

2.2See Diagram 2.1b. Where served by only one stair, all habitable rooms (excluding kitchens) should have either of the following.

a.An emergency escape window or external door, as described in paragraph 2.10.

b.Direct access to a protected stairway, as described in paragraph 2.5a.

2.3Two rooms may be served by a single window. A door between the rooms should provide access to the window without passing through the stair enclosure. Both rooms should have their own access to the internal stair.

Escape from upper storeys more than 4.5m above ground level

2.4Dwellinghouses with one internal stair should comply with paragraphs 2.5 and 2.6. In dwellinghouses with more than one stair, the stairs should provide effective alternative means of escape. The stairs should be physically separated by either of the following.

a.Fire resisting construction (minimum REI 30).

b.More than one room.

Dwellinghouses with one storey more than 4.5m above ground level

2.5See Diagram 2.1c. The dwellinghouse should have either of the following.

a.Protected stairway – a stair separated by fire resisting construction (minimum REI 30) at all storeys, that complies with one of the following.

i.Extends to a final exit (Diagram 2.2a).

ii.Gives access to a minimum of two ground level final exits that are separated from each other by fire resisting construction (minimum REI 30) and fire doorsets (minimum E 20) (Diagram 2.2b).

Cavity barriers or a fire resisting ceiling (minimum EI 30) should be provided above a protected stairway enclosure (Diagram 2.3).

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b.Alternative escape route – a top storey separated from lower storeys by fire resisting construction (minimum REI 30) and with an alternative escape route leading to its own final exit.

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Dwellinghouses with two or more storeys more than 4.5m above ground level

2.6See Diagram 2.1d. In addition to meeting the provisions in paragraph 2.5, the dwellinghouse should comply with either of the following.

a.Provide an alternative escape route from each storey more than 7.5m above ground level. At the first storey above 7.5m, the protected stairway should be separated from the lower storeys by fire resisting construction (minimum REI 30) if the alternative escape route is accessed via either of the following.

i.The protected stairway to an upper storey.

ii.A landing within the protected stairway enclosure to an alternative escape route on the same storey. The protected stairway at or about 7.5m above ground level should be separated from the lower storeys or levels by fire resisting construction (see Diagram 2.4).

b.Provide a sprinkler system throughout, designed and installed in accordance with BS 9251.

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Passenger lifts

2.7A passenger lift serving any storey more than 4.5m above ground level should be in either of the following.

a.The enclosure to the protected stairway, as described in paragraph 2.5.

b.A fire resisting lift shaft (minimum REI 30).

Air circulation systems

2.8Air circulation systems which circulate air within an individual dwellinghouse with a floor more than 4.5m above ground level should meet the guidance given in paragraph 2.9.

2.9All of the following precautions should be taken to avoid the spread of smoke and fire to the protected stairway.

a.Transfer grilles should not be fitted in any wall, door, floor or ceiling of the stair enclosure.

b.Any duct passing through the stair enclosure should be rigid steel. Joints between the ductwork and stair enclosure should be fire-stopped.

c.Ventilation ducts supplying or extracting air directly to or from a protected stairway should not serve other areas as well.

d.Any system of mechanical ventilation which recirculates air and which serves both the stair and other areas should be designed to shut down on the detection of smoke within the system.

e.For ducted warm air heating systems, a room thermostat should be sited in the living room. It should be mounted at a height between 1370mm and 1830mm above the floor. The maximum setting should be 27°C.

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Emergency escape windows and external doors

2.10Windows or external doors providing emergency escape should comply with all of the following.

a.Windows should have an unobstructed openable area that complies with all of the following.

i.A minimum area of 0.33m².

ii.A minimum height of 450mm and a minimum width of 450mm (the route through the window may be at an angle rather than straight through).

iii.The bottom of the openable area is a maximum of 1100mm above the floor.

b.People escaping should be able to reach a place free from danger from fire. Courtyards or inaccessible back gardens should comply with Diagram 2.5.

c.Locks (with or without removable keys) and opening stays (with child-resistant release catches) may be fitted to escape windows.

d.Windows should be capable of remaining open without being held.

Inner rooms

2.11An inner room is permitted when it is one of the following.

a.A kitchen.

b.A laundry or utility room.

c.A dressing room.

d.A bathroom, WC or shower room.

e.Any room on a storey that is a maximum of 4.5m above ground level which is provided with an emergency escape window as described in paragraph 2.10.

f.A gallery that complies with paragraph 2.15.

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2.12A room accessed only via an inner room (an inner inner room) is acceptable when all of the following apply.

a.It complies with paragraph 2.11.

b.The access rooms each have a smoke alarm (see Section 1).

c.None of the access rooms is a kitchen.

Balconies and flat roofs

2.13Where a flat roof forms part of a means of escape, it should comply with all of the following.

a.It should be part of the same building from which escape is being made.

b.The route across the roof should lead to a storey exit or external escape route.

c.The part of the roof (including its supporting structure) forming the escape route, and any opening within 3m of the escape route, should be of fire resisting construction (minimum REI 30).

2.14A balcony or flat roof intended to form part of an escape route should be provided with guarding etc. in accordance with Approved Document K.

Galleries

2.15A gallery should comply with one of the following.

a.It should be provided with an alternative exit.

b.It should be provided with an emergency escape window, as described in paragraph 2.10, where the gallery floor is a maximum of 4.5m above ground level.

c.It should meet all the conditions shown in Diagram 2.6.

Basements

2.16Basement storeys containing habitable rooms should have one of the following.

a.An emergency escape window or external door providing escape from the basement (paragraph 2.10).

b.A protected stairway (paragraph 2.5a) leading from the basement to a final exit.

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2.17Any external escape stair should meet all of the following conditions (Diagram 2.7).

a.Doors to the stair should be fire resisting (minimum E 30), except for a single exit door from the building to the top landing of a downward-leading external stair.

b.Fire resisting construction (minimum RE 30) is required for the building envelope within the following zones, measured from the flights and landings of the external stair.

i.1800mm horizontally.

ii.9m vertically below.

iii.1100mm above the top landing of the stair (except where the stair leads from basement to ground level).

c.Fire resisting construction (minimum RE 30) should be provided for any part of the building (including doors) within 1800mm of the escape route from the foot of the stair to a place of safety. This does not apply if there are alternative escape routes from the foot of the external escape stair.

d.Stairs more than 6m in height should be protected from adverse weather. Protection should prevent the build-up of snow or ice but does not require full enclosure.

e.Glazing in areas of fire resisting construction should be fixed shut and fire resisting (in terms of integrity, but not insulation) (minimum E 30).

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Replacement windows

2.18Work should comply with Parts K and L of Schedule 1 to the Building Regulations. When complete, the building should comply with other applicable parts of Schedule 1 to at least the same level as before.

2.19Where an existing window would be an escape window in a new dwellinghouse, and is big enough to be used for escape purposes, then the replacement should comply with one of the following.

a.The replacement window should be sized to provide at least the same potential for escape.

b.If the existing window was larger than required for escape purposes, the opening can be reduced to the minimum described in paragraph 2.10.

2.20If windows are replaced, it may be necessary to provide cavity barriers around the opening in accordance with Section 5.

Loft conversions

2.21Where a new storey is added through conversion to create a storey above 4.5m, both of the following should apply.

a.The full extent of the escape route should be addressed.

b.Fire resisting doors (minimum E 20) and partitions (minimum REI 30) should be provided, including upgrading the existing doors where necessary.

2.22Where it is undesirable to replace existing doors because of historical or architectural merit, the possibility of retaining, and where necessary upgrading, them should be investigated.

2.23An alternative approach to that described in paragraph 2.21 would be to comply with all of the following.

a.Provide sprinkler protection to the open-plan areas.

b.Provide a fire resisting partition (minimum REI 30) and door (minimum E 20) to separate the ground storey from the upper storeys. The door should allow occupants of the loft room access to a first storey escape window.

c.Separate cooking facilities from the open-plan area with fire resisting construction (minimum REI 30).

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Introduction

3.1Separate guidance applies to means of escape within the flat and within the common parts of the building that lead to a place of safety. Flats at ground level are treated similarly to dwellinghouses. With increasing height, more complex provisions are needed.

3.2The provisions in this section make the following assumptions.

a.Any fire is likely to be in a flat.

b.There is no reliance on external rescue.

c.Simultaneous evacuation of all flats is unlikely to be necessary due to compartmentation.

d.Fires in common parts of the building should not spread beyond the fabric in the immediate vicinity. In some cases, however, communal facilities exist that require additional measures to be taken.

3.3Provisions are recommended to support a stay put evacuation strategy for blocks of flats. It is based on the principle that a fire is contained in the flat of origin and common escape routes are maintained relatively free from smoke and heat. It allows occupants, some of whom may require assistance to escape in the event of a fire, in other flats that are not affected to remain.

Sufficient protection to common means of escape is necessary to allow occupants to escape should they choose to do so or are instructed/aided to by the fire service. A higher standard of protection is therefore needed to ensure common escape routes remain available for a longer period than is provided in other buildings.

3.4Paragraphs 3.6 to 3.23 deal with the means of escape within each flat. Paragraphs 3.25 to 3.89 deal with the means of escape in common areas of the building (including mixed use buildings in paragraphs 3.76 and 3.77). Guidance for live/work units is given in paragraph 3.24.

General provisions

Mixed use buildings

3.5In mixed use buildings, separate means of escape should be provided from any storeys or parts of storeys used for the ‘residential’ or ‘assembly and recreation’ purpose groups (purpose groups 1, 2 and 5), other than in the case of certain small buildings or buildings in which the residential accommodation is ancillary (see paragraphs 3.76 and 3.77)

Emergency escape windows and external doors

3.6Windows or external doors providing emergency escape should comply with all of the following.

a.Windows should have an unobstructed openable area that complies with all of the following.

i.A minimum area of 0.33m².

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ii.A minimum height of 450mm and a minimum width of 450mm (the route through the window may be at an angle rather than straight through).

iii.The bottom of the openable area is a maximum of 1100mm above the floor.

b.People escaping should be able to reach a place free from danger from fire.

c.Locks (with or without removable keys) and opening stays (with child-resistant release catches) may be fitted to escape windows.

d.Windows should be capable of remaining open without being held.

Inner rooms

3.7An inner room is permitted when it is one of the following.

a.A kitchen.

b.A laundry or utility room.

c.A dressing room.

d.A bathroom, WC or shower room.

e.Any room on a storey that is a maximum of 4.5m above ground level which is provided with an emergency escape window as described in paragraph 3.6.

f.A gallery that complies with paragraph 3.13.

3.8A room accessed only via an inner room (an inner inner room) is acceptable when all of the following apply.

a.It complies with paragraph 3.7.

b.The access rooms each have a smoke alarm (see Section 1).

c.None of the access rooms is a kitchen.

Basements

3.9Basement storeys containing habitable rooms should have one of the following.

a.An emergency escape window or external door providing escape from the basement (see paragraph 3.6).

b.A protected stairway (minimum REI 30) leading from the basement to a final exit.

Balconies and flat roofs

3.10Where a flat roof forms part of a means of escape, it should comply with all of the following.

a.It should be part of the same building from which escape is being made.

b.The route across the roof should lead to a storey exit or external escape route.

c.The part of the roof (including its supporting structure) forming the escape route, and any opening within 3m of the escape route, should be of fire resisting construction (minimum REI 30).

3.11A balcony or flat roof intended to form part of an escape route should be provided with guarding etc. in accordance with Approved Document K.

3.12For flats more than 4.5m above ground level, a balcony outside an alternative exit should be a common balcony meeting the conditions described in paragraph 3.22.

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3.13A gallery should comply with one of the following.

a.It should be provided with an alternative exit.

b.It should be provided with an emergency escape window, as described in paragraph 3.6, where the gallery floor is a maximum of 4.5m above ground level.

c.It should meet the conditions shown in Diagram 3.1.

Flats with upper storeys a maximum of 4.5m above ground level

3.14The internal arrangement of single storey or multi-storey flats should comply with paragraphs 3.15 to 3.17. Alternatively, the guidance in paragraphs 3.18 to 3.22 may be followed. Where a flat is accessed via the common parts of a block of flats it may be necessary to provide a protected entrance hall to meet the provisions of paragraph 3.28 and Diagram 3.9.

Escape from the ground storey

3.15All habitable rooms (excluding kitchens) should have either of the following.

a.An opening directly onto a hall leading to a final exit.

b.An emergency escape window or door, as described in paragraph 3.6.

Escape from upper storeys a maximum of 4.5m above ground level

3.16All habitable rooms (excluding kitchens) should have either of the following.

a.An emergency escape window or external door, as described in paragraph 3.6.

b.In multi-storey flats, direct access to a protected internal stairway (minimum REI 30) leading to an exit from the flat.

3.17Two rooms may be served by a single escape window. A door between rooms should provide access to the escape window without passing through the stair enclosure. Both rooms should have their own access to the internal stair.

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Internal planning of single storey flats

3.18One of the following approaches should be adopted, observing the inner room restrictions described in paragraphs 3.7 and 3.8.

a.Provide a protected entrance hall (minimum REI 30) serving all habitable rooms that meets the conditions shown in Diagram 3.2.

b.Plan the flat to meet the conditions shown in Diagram 3.3, so that both of the following apply.

i.The travel distance from the flat entrance door to any point in any habitable room is a maximum of 9m.

ii.Cooking facilities are remote from the main entrance door and do not impede the escape route from anywhere in the flat.

c.Provide an alternative exit from the flat complying with paragraph 3.19.

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3.19Where access from any habitable room to the entrance hall or flat entrance is impossible without passing through another room, all of the following conditions should be met (Diagram 3.4).

a.Bedrooms should be separated from living accommodation by fire resisting construction (minimum REI 30) and fire doorsets (minimum E 20).

b.The alternative exit should be in the part of the flat that contains the bedrooms.

Internal planning of multi-storey flats

3.20A multi-storey flat with an independent external entrance at ground level is similar to a dwellinghouse and means of escape should be planned on the basis of Section 2, depending on the height of the top storey above ground level.

3.21When multi-storey flats do not have their own external entrance at ground level, adopt one of the following approaches.

a.Approach 1 – provide at least one alternative exit from each habitable room that is not on the entrance storey of the flat (Diagram 3.5 and paragraph 3.22).

b.Approach 2 – provide at least one alternative exit from each storey that is not the entrance storey of the flat. All habitable rooms should have direct access to a protected landing (Diagram 3.6 and paragraph 3.22).

c.Approach 3 – provide a protected stairway plus a sprinkler system in accordance with Appendix E (smoke alarms should also be provided in accordance with Section 1).

d.Approach 4 – if the vertical distance between the entrance storey of the flat and any of the storeys above or below does not exceed 7.5m, provide all of the following.

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i.A protected stairway.

ii.Additional smoke alarms in all habitable rooms.

iii.A heat alarm in any kitchen.

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3.22Any alternative exit from a flat should comply with all of the following.

a.It should be remote from the main entrance door to the flat.

b.It should lead to a final exit, via a common stair if necessary, through one of the following.

i.A door to an access corridor, access lobby or common balcony.

ii.An internal private stair leading to an access corridor, access lobby or common balcony at another level.

iii.A door to a common stair.

iv.A door to an external stair.

v.A door to an escape route over a flat roof.

Any access route leading to a final exit or common stair should comply with the provisions for means of escape in the common parts of a flat (see paragraph 3.25).

Air circulation systems in flats with a protected stairway or entrance hall enclosure

3.23For systems circulating air only within an individual flat, take all of the following precautions.

a.Transfer grilles should not be fitted in any wall, door, floor or ceiling of the enclosure.

b.Any duct passing through the enclosure should be rigid steel. Joints between the ductwork and enclosure should be fire-stopped.

c.Ventilation ducts serving the enclosure should not serve any other areas.

d.Any system of mechanical ventilation which recirculates air and which serves both the stair and other areas should be designed to shut down on the detection of smoke within the system.

e.For ducted warm air heating systems, a room thermostat should be sited in the living room. It should be mounted at a height between 1370mm and 1830mm above the floor. The maximum setting should be 27°C.

Live/work units

3.24For flats serving as a workplace for both occupants and people who do not live on the premises, provide both of the following.

a.A maximum travel distance of 18m between any part of the working area and either of the following.

i.The flat entrance door.

ii.An alternative means of escape that is not a window.

If the travel distance is over 18m, the assumptions in paragraph 3.2 may not be valid. The design should be considered on a case-by-case basis.

b.Escape lighting to windowless accommodation in accordance with BS 5266-1.

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3.25The following paragraphs deal with means of escape from the entrance doors of flats to a final exit. They do not apply to flats with a top storey that is a maximum of 4.5m above ground level (designed in accordance with paragraphs 3.15 to 3.17).

Reference should also be made to the following.

a.Requirement B3 regarding compartment walls and protected shafts.

b.Requirement B5 regarding access for the fire and rescue service.

Number of escape routes

3.26A person escaping through the common area, if confronted by the effects of a fire in another flat, should be able to turn away from it and make a safe escape via an alternative route.

3.27From the flat entrance door, a single escape route is acceptable in either of the following cases.

a.The flat is on a storey served by a single common stair and both of the following apply.

i.Every flat is separated from the common stair by a protected lobby or common protected corridor (see Diagram 3.7).

ii.The maximum travel distance in Table 3.1, for escape in one direction only, is not exceeded.

b.The flat is in a dead end of a common corridor served by two (or more) common stairs and the maximum travel distance given in Table 3.1, for escape in one direction only, is not exceeded (Diagram 3.8).

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Source page 112

Small single stair buildings

3.28For some low rise buildings, the provisions in paragraphs 3.26 and 3.27 may be modified and the use of a single stair, protected in accordance with Diagram 3.9, may be permitted where all of the following apply.

a.The top storey of the building is a maximum of 11m above ground level.

b.No more than three storeys are above the ground storey.

c.The stair does not connect to a covered car park, unless the car park is open sided (as defined in Section 11 of Approved Document B Volume 2).

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d.The stair does not serve offices, stores or other ancillary accommodation. If it does, they should be separated from the stair by a protected lobby or protected corridor (minimum REI 30) with a minimum 0.4m² of permanent ventilation, or be protected from the ingress of smoke by a mechanical smoke control system.

e.Either of the following is provided for the fire and rescue service.

i.A high-level openable vent with a free area of at least 1m² at each storey.

ii.A single openable vent with a free area of at least 1m² at the head of the stair, operable remotely at the fire and rescue service access level.

Flats with balcony or deck access

3.29Paragraph 3.27 may be modified using the guidance in clause 7.3 of BS 9991.

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3.30Where a storey or part of a building has multiple escape routes available, one may be over a flat roof that complies with all of the following.

a.It should be part of the same building from which escape is being made.

b.The route across the roof should lead to a storey exit or external escape route.

c.The part of the roof (including its supporting structure) forming the escape route, and any opening within 3m of the escape route, should be of fire resisting construction (minimum REI 30).

d.The route should be clearly defined and guarded by walls and/or protective barriers to protect against falling.

Common escape routes

3.31The following paragraphs deal with means of escape from the entrance doors of flats to a final exit.

3.32Escape route travel distances should comply with Table 3.1.

3.33An escape route should not pass through one stair enclosure to reach another. It may pass through a protected lobby (minimum REI 30) of one stair to reach another.

3.34Common corridors should be protected corridors. The wall between each flat and the corridor should be a compartment wall (minimum REI 30 where the top storey is up to 5m above ground level, otherwise REI 60).

3.35Divide a common corridor connecting two or more storey exits with a fire doorset fitted with a self-closing device (minimum E 30 Sa). See Diagram 3.8. Associated screens should be fire resisting. Site doors so that smoke does not affect access to more than one stair.

3.36A fire doorset (minimum E 30 Sa) fitted with a self-closing device (and fire resisting screen, where required) should separate the dead-end portion of a common corridor from the rest of the corridor (Diagrams 3.7a, 3.8b and 3.8c).

3.37Ancillary accommodation should not be located in, or entered from, a protected lobby or protected corridor forming the only common escape route on that storey.

Headroom in common escape routes

3.38Escape routes should have a minimum clear headroom of 2m. The only projections allowed below this height are door frames.

Flooring of common escape routes

3.39Escape route floor finishes should minimise their slipperiness when wet. Finishes include the treads of steps and surfaces of ramps and landings.

Ramps and sloping floors

3.40A ramp forming part of an escape route should meet the provisions in Approved Document M. Any sloping floor or tier should have a pitch of not more than 35 degrees to the horizontal.

Lighting of common escape routes

3.41Except for two storey blocks of flats, all escape routes should have adequate artificial lighting. If the mains electricity power supply fails, escape lighting should illuminate the route (including external escape routes).

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3.42In addition, escape lighting should be provided to all of the following.

a.Toilet accommodation with a minimum floor area of 8m².

b.Electricity and generator rooms.

c.Switch room/battery room for emergency lighting system.

d.Emergency control rooms.

3.43Escape stair lighting should be on a separate circuit from the electricity supply to any other part of the escape route.

3.44Escape lighting should conform to BS 5266-1.

Exit signs on common escape routes

3.45Every doorway or other exit providing access to a means of escape, other than exits in ordinary use (e.g. main entrances), should be distinctively and conspicuously marked by an exit sign in accordance with BS ISO 3864-1 and BS 5499-4. For this reason, blocks of flats with a single stair in regular use would not usually require any fire exit signage.

Advice on fire safety signs, including emergency escape signs, is given in the HSE publication Safety Signs and Signals: Guidance on Regulations.

Some buildings may require additional signs to comply with other legislation.

Protected power circuits

3.46To limit potential damage to cables in protected circuits, all of the following should apply.

a.Cables should be sufficiently robust.

b.Cable routes should be carefully selected and/or physically protected in areas where cables may be exposed to damage.

c.Methods of cable support should be class A1 rated and offer at least the same integrity as the cable. They should maintain circuit integrity and hold cables in place when exposed to fire.

3.47A protected circuit to operate equipment during a fire should achieve all of the following.

a.Cables should achieve PH 30 classification when tested in accordance with BS EN 50200 (incorporating Annex E) or an equivalent standard.

b.It should only pass through parts of the building in which the fire risk is negligible.

c.It should be separate from any circuit provided for another purpose.

3.48Guidance on cables for large and complex buildings is given in BS 5839-1, BS 5266-1 and BS 8519.

Smoke control in common escape routes

3.49Despite the provisions described, it is probable that some smoke will get into the common corridor or lobby from a fire in a flat.

There should therefore be some means of ventilating the common corridors/lobbies to control smoke and so protect the common stairs. This means of ventilation offers additional protection to that provided by the fire doors to the stair, as well as some protection to the corridors/lobbies.

Ventilation can be natural (paragraphs 3.50 to 3.53) or mechanical (paragraph 3.54).

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3.50Except in buildings that comply with Diagram 3.9, the corridor or lobby next to each stair should have a smoke vent. The location of the vent should comply with both of the following.

a.Be as high as practicable.

b.Be positioned so the top edge is at least as high as the top of the door to the stair.

3.51Smoke vents should comply with one of the following.

a.They should be located on an external wall with minimum free area of 1.5m².

b.They should discharge into a vertical smoke shaft, closed at the base, that meets all of the following criteria.

i.The shaft should conform to the following conditions.

•Have a minimum cross-sectional area of 1.5m² (minimum dimension 0.85m in any direction).

•Open at roof level, minimum 0.5m above any surrounding structures within 2m of it horizontally.

•Extend a minimum of 2.5m above the ceiling of the highest storey served by the shaft.

ii.The free area of all the following vents should be a minimum of 1m² in the following places.

•From the corridor or lobby into the shaft.

•At the opening at the head of the shaft.

•At all internal locations within the shaft (e.g. safety grilles).

iii.The smoke shaft should be constructed from a class A1 material. All vents should either be a smoke leakage (Sa) rated fire doorset (see Appendix C, Table C1, item 2.e for minimum fire resistance) or fitted with a smoke control damper achieving the same period of fire resistance and designed to operate as described below. The shaft should be vertical from base to head, with a maximum of 4m at a maximum inclined angle of 30 degrees.

iv.If smoke is detected in the common corridor or lobby, both of the following should occur.

•Simultaneous opening of vents on the storey where the fire is located, at the top of the smoke shaft and to the stair.

•Vents from the corridors or lobbies on all other storeys should remain closed, even if smoke is subsequently detected on storeys other than where the fire is located.

3.52A vent to the outside with a minimum free area of 1m² should be provided from the top storey of the stair.

3.53In single stair buildings, smoke vents on the storey where the fire is initiated, and the vent at the head of the stair, should be activated by smoke detectors in the common parts.

In buildings with more than one stair, smoke vents may be activated manually. The control system should open the vent at the head of the stair before, or at the same time as, the vent on the storey where the fire is located. Smoke detection is not required for ventilation purposes in this instance.

Smoke control of common escape routes by mechanical ventilation

3.54Guidance on the design of smoke control systems that use pressure differentials is available in BS EN 12101-6.

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3.55Refuse storage chambers, refuse chutes and refuse hoppers should be sited and constructed in accordance with BS 5906.

3.56Refuse chutes and rooms for storing refuse should meet both of the following conditions.

a.Be separated from other parts of the building by fire resisting construction (minimum REI 30 in buildings with a top storey up to 5m above ground level; otherwise REI 60).

b.Not be situated within a protected stairway or protected lobby.

3.57The approach to rooms containing refuse chutes or for storing refuse should comply with one of the following conditions.

a.Be directly from the open air.

b.Be through a protected lobby with a minimum of 0.2m² of permanent ventilation.

3.58Access openings to refuse storage chambers should not be sited in the following areas.

a.Next to escape routes or final exits.

b.Near the windows of flats.

Common stairs

Number of common stairs

3.59A building should provide access to more than one common stair if it does not meet the criteria for a single common stair (see paragraph 3.26 and 3.27).

Width of common stairs

3.60A stair of acceptable width for everyday use will be sufficient for escape purposes. If it is also a firefighting stair, it should be at least 1100mm wide. The width is the clear width between the walls or balustrades. Any handrails and strings intruding into that width by a maximum of 100mm on each side may be ignored.

Protection of common stairs

3.61Section 7 provides guidance on avoiding the spread of fire between storeys. For a stair that is also a firefighting stair, guidance in Section 15 should be followed.

Enclosure of common stairs

3.62Every common stair should be a protected stairway. Where the protected stairway passes from one compartment to another, it should be within a protected shaft.

External walls adjacent to protected stairways

3.63With some configurations of external wall, a fire in one part of a building could subject the external wall of a protected stairway to heat (for example, where the two are adjacent at an internal angle in the façade, as shown in Diagram 3.10).

3.64If a protected stairway projects beyond, is recessed from or is in an internal angle of the adjoining external wall of the building, then the minimum distance between an unprotected area of the building enclosure and an unprotected area of the stair enclosure should be 1800mm.

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External escape stairs

3.65Flats may be served by an external stair if the provisions in paragraphs 3.66 to 3.69 are followed.

3.66Where a storey (or part of a building) is served by a single access stair, that stair may be external provided both of the following conditions are met.

a.The stair serves a floor not more than 6m above the ground level.

b.The stair meets the provisions in paragraph 3.68.

3.67Where more than one escape route is available from a storey (or part of a building), then some of the escape routes from that storey or part of the building may be by way of an external stair provided all of the following conditions are met:

a.There is a at least one internal escape stair from every part of each storey (excluding plant areas).

b.The stair serves a floor not more than 6m above either the ground level or a roof podium which is itself served by an independent protected stairway.

c.The stair meets the provisions in paragraph 3.68.

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3.68Any external escape stair should meet all of the following conditions (Diagram 3.11).

a.Doors to the stair should be fire resisting (minimum E 30) and be fitted with a self-closing device, except for a single exit door from the building to the top landing of a downward-leading external stair, provided it is the only door onto the landing.

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b.Fire resisting construction (minimum RE 30) is required for the building envelope within the following zones, measured from the flights and landings of the external stair.

i.1800mm above and horizontally.

ii.9m vertically below.

iii.1100mm above the top landing of the stair (except where the stair leads from basement to ground level).

c.Fire resisting construction (minimum RE 30) should be provided for any part of the building (including doors) within 1800mm of the escape route from the foot of the stair to a place of safety. This does not apply if there are alternative escape routes from the foot of the external escape stair.

d.Glazing in areas of fire resisting construction should be fixed shut and fire resisting (in terms of integrity but not insulation) (minimum E 30).

e.Stairs more than 6m in height above ground level (e.g. where they are provided above a podium) should be protected from adverse weather. Protection should prevent the build-up of snow or ice but does not require full enclosure.

3.69Access to an external escape stair may be via a flat roof, provided the flat roof meets the requirements of paragraph 3.30.

Separation of adjoining protected stairways

3.70The construction separating two adjacent protected stairways (or exit passageways leading to different final exits) should be imperforate.

Basement stairs

3.71If a building does not meet the criteria of paragraph 3.28, an escape stair forming part of the only escape route from an upper storey should not continue down to serve a basement storey. The basement storey should be served by a separate escape stair.

3.72Where multiple escape stairs serve the upper storeys, only one needs to end at ground level. Other stairs may connect with the basement storeys if there is a protected lobby or a protected corridor between the stairs and accommodation at each basement level.

Stairs serving ancillary accommodation

3.73Except in buildings described in paragraph 3.28, common stairs forming part of the only escape route from a flat should not serve any of the following.

a.Covered car park.

b.Boiler room.

c.Fuel storage space.

d.Other ancillary accommodation of similar fire risk.

3.74Where a common stair is not part of the only escape route from a flat, it may also serve ancillary accommodation from which it is separated by a protected lobby or protected corridor (minimum REI 30).

3.75Where a stair serves an enclosed car park or place of special fire hazard, the lobby or corridor should have a minimum 0.4m² of permanent ventilation or be protected from the ingress of smoke by a mechanical smoke control system.

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3.76In buildings with a maximum of three storeys above the ground storey, stairs may serve both flats and other occupancies, provided that the stairs are separated from each occupancy by protected lobbies (minimum REI 30) at each storey.

3.77In buildings with more than three storeys above the ground storey, stairs may serve the flats and other occupancies if all of the following apply.

a.The flat is ancillary to the main use of the building.

b.The flat has an independent alternative escape route.

c.The stair is separated from occupancies on lower storeys by a protected lobby (minimum REI 30) at each of those storeys.

d.The stair enclosure has at least the same standard of fire resistance as the structural elements of the building (see Appendix B, Table B4); if the stair is a firefighting stair, it should comply with the provisions in Section 15 (see also paragraph 3.60).

e.Any automatic fire detection and alarm system fitted in the main part of the building also covers all flats.

f.Any security measures in any parts of the building do not prevent escape at all material times.

Use of space within protected stairways

3.78A protected stairway should not be used for anything else, except a lift well or electricity meters.

Electricity meter(s) in protected stairways

3.79In single stair buildings, electricity meters should be in securely locked cupboards. Cupboards should be separated from the escape route by fire resisting construction.

Gas service and installation pipes in protected stairways

3.80Gas service and installation pipes and meters should not be within a protected stairway, unless installed in accordance with the Pipelines Safety Regulations 1996 and the Gas Safety (Installation and Use) Regulations 1998.

Exits from protected stairways

3.81Every protected stairway should lead to a final exit, either directly or via a protected exit passageway. Any protected exit corridor or stair should have the same standard of fire resistance and lobby protection as the stair it serves.

Construction of escape stairs

3.82The flights and landings of escape stairs should be constructed of materials achieving class A2-s3, d2 or better in all of the following situations.

a.If the escape stair is the only stair in a building with more than three storeys.

b.If the escape stair is within a basement storey.

c.If the escape stair serves any storey that has a floor level more than 18m above ground or access level.

d.If the escape stair is an external escape stair, except where the stair connects the ground storey or ground level with a floor or flat roof a maximum of 6m above or below ground level.

e.If the escape stair is a firefighting stair.

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Materials achieving class B-s3, d2 or worse may be added to the top horizontal surface, except on firefighting stairs.

3.83Further guidance on the construction of firefighting stairs is given in Section 15 (see also paragraph 3.60). Dimensional constraints on the design of stairs are given in Approved Document K.

Single steps

3.84Single steps on escape routes should be prominently marked. A single step on the line of a doorway is acceptable, subject to paragraph 3.107.

Fixed ladders

3.85Fixed ladders should not be provided as a means of escape for members of the public. They should only be provided where a conventional stair is impractical, such as for access to plant rooms which are not normally occupied.

Helical stairs and spiral stairs

3.86Helical stairs and spiral stairs may form part of an escape route provided they are designed in accordance with BS 5395-2. If they are intended to serve members of the public, stairs should be type E (public) stairs.

Fire resistance of doors

3.87Fire resistance test criteria are set out in Appendix C. Standards of performance are summarised in Table C1.

Fire resistance of glazed elements

3.88If glazed elements in fire resisting enclosures and doors can only meet the required integrity performance, their use is limited. These limitations depend on whether the enclosure forms part of a protected shaft (see Section 7) and the provisions set out in Appendix B, Table B5. If both integrity and insulation performance can be met, there is no restriction in this document on the use or amount of glass.

3.89Glazed elements should also comply with the following, where necessary.

a.If the enclosure forms part of a protected shaft: Section 7.

b.Appendix B, Table B5.

c.Guidance on the safety of glazing: Approved Document K.

Doors on escape routes

3.90Doors should be readily openable to avoid undue delay to people escaping. Doors on escape routes (both within and from the building) should comply with paragraphs 3.91 to 3.98. Guidance on door closing and ‘hold open’ devices for fire doorsets is set out in Appendix C.

Door fastenings

3.91In general, doors on escape routes (whether or not the doors are fire doorsets) should be either of the following.

a.Not fitted with a lock, latch or bolt fastenings.

b.Fitted only with simple fastenings that are all of the following.

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i.Easy to operate; it should be apparent how to undo the fastening.

ii.Operable from the side approached by people escaping.

iii.Operable without a key.

iv.Operable without requiring people to manipulate more than one mechanism.

Doors may be fitted with hardware to allow them to be locked when rooms are empty.

If a secure door is operated by code or combination keypad, swipe or proximity card, biometric data, etc., a security mechanism override should be possible from the side approached by people escaping.

3.92Electrically powered locks should return to the unlocked position in all of the following situations.

a.If the fire detection and alarm system operates.

b.If there is loss of power or system error.

c.If the security mechanism override is activated.

Security mechanism overrides for electrically powered locks should be a Type A call point, as described in BS 7273-4. The call point should be positioned on the side approached by people escaping. If the door provides escape in either direction, a call point should be installed on both sides of the door.

3.93Guidance on door closing and ‘hold open’ devices for fire doorsets is set out in Appendix C.

Direction of opening

3.94The door of any doorway or exit should be hung to open in the direction of escape whenever reasonably practicable. It should always be hung to open in the direction of escape if more than 60 people might be expected to use it during a fire.

Amount of opening and effect on associated escape routes

3.95All doors on escape routes should be hung to meet both of the following conditions.

a.Open by a minimum of 90 degrees.

b.Open with a swing that complies with both of the following.

i.Is clear of any change of floor level, other than a threshold or single step on the line of the doorway.

ii.Does not reduce the effective width of any escape route across a landing.

3.96Any door opening towards a corridor or a stair should be recessed to prevent its swing encroaching on the effective width.

Vision panels in doors

3.97Doors should contain vision panels in both of the following situations.

a.Where doors on escape routes divide corridors.

b.Where doors are hung to swing both ways.

Approved Document M contains guidance about vision panels in doors across accessible corridors and Approved Document K contains guidance about the safety of glazing.

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3.98Where revolving doors, automatic doors and turnstiles are placed across escape routes they should comply with one of the following.

a.They are automatic doors of the required width and comply with one of the following conditions.

i.Their failsafe system provides outward opening from any open position.

ii.They have a monitored failsafe system to open the doors if the mains electricity supply fails.

iii.They fail safe to the open position if the power fails.

b.Non-automatic swing doors of the required width are provided immediately adjacent to the revolving or automatic door or turnstile.

Lifts

Fire protection of lift installations

3.99Lift wells should comply with one of the following conditions.

a.Be sited within the enclosures of a protected stairway.

b.Be enclosed with fire resisting construction (minimum REI 30) when in a position that might prejudice the means of escape.

3.100A lift well connecting different compartments should form a protected shaft (see Section 7).

3.101In buildings designed for phased evacuation or progressive horizontal evacuation, if the lift well is not within the enclosures of a protected stairway, its entrance should be separated at every storey by a protected lobby (minimum REI 30).

3.102In basements and enclosed car parks, the lift should be within the enclosure of a protected stairway. Otherwise, the lift should be approached only via a protected lobby or protected corridor (minimum REI 30).

3.103If a lift delivers into a protected corridor or protected lobby serving sleeping accommodation and also serves a storey containing a high fire risk (such as a kitchen, communal areas, stores, etc.) then the lift should be separated from the high fire risk area(s) by a protected lobby or protected corridor (minimum REI 30).

3.104A lift shaft serving storeys above ground level should not serve any basement, if either of the following applies.

a.There is only one escape stair serving storeys above ground level and smoke from a basement fire would adversely affect escape routes in the upper storeys.

b.The lift shaft is within the enclosure to an escape stair that terminates at ground level.

3.105Lift machine rooms should be sited over the lift well where possible. Where buildings or part of a building with only one stairway make this arrangement impractical, the lift machine room should be sited outside the protected stairway.

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3.106People should be able to rapidly leave the area around the building. Direct access to a street, passageway, walkway or open space should be available. The route away from the building should comply with the following.

a.Be well defined.

b.If necessary, have suitable guarding.

3.107Final exits should not present a barrier for disabled people. Where the route to a final exit does not include stairs, a level threshold and, where necessary, a ramp should be provided.

3.108Final exit locations should be clearly visible and recognisable.

3.109Final exits should avoid outlets of basement smoke vents and openings to transformer chambers, refuse chambers, boiler rooms and similar risks.

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This section deals with the following requirement from Part B of Schedule 1 to the Building Regulations 2010.

Intention

In the Secretary of State’s view, requirement B2 is met by achieving a restricted spread of flame over internal linings. The building fabric should make a limited contribution to fire growth, including a low rate of heat release.

It is particularly important in circulation spaces, where linings may offer the main means by which fire spreads and where rapid spread is most likely to prevent occupants from escaping.

Requirement B2 does not include guidance on the following.

a.Generation of smoke and fumes.

b.The upper surfaces of floors and stairs.

c.Furniture and fittings.

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Classification of linings

4.1The surface linings of walls and ceilings should meet the classifications in Table 4.1.

Walls

4.2For the purposes of this requirement, a wall includes both of the following.

a.The internal surface of internal and external glazing (except glazing in doors).

b.Any part of a ceiling which slopes at an angle greater than 70 degrees to the horizontal.

4.3For the purposes of this requirement, a wall does not include any of the following.

a.Doors and door frames.

b.Window frames and frames in which glazing is fitted.

c.Architraves, cover moulds, picture rails, skirtings and similar narrow members.

d.Fireplace surrounds, mantle shelves and fitted furniture.

4.4Parts of walls in rooms may be of lower performance than stated in Table 4.1, but no worse than class D-s3, d2. In any one room, the total area of lower performance wall lining should be less than an area equivalent to half of the room’s floor area, up to a maximum of 20m² of wall lining.

Ceilings

4.5For the purposes of this requirement, a ceiling includes all of the following.

a.Glazed surfaces.

b.Any part of a wall at 70 degrees or less to the horizontal.

c.The underside of a gallery.

d.The underside of a roof exposed to the room below.

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4.6For the purposes of this requirement, a ceiling does not include any of the following.

a.Trap doors and their frames.

b.The frames of windows or rooflights and frames in which glazing is fitted.

c.Architraves, cover moulds, picture rails, exposed beams and similar narrow members.

Rooflights

4.7Rooflights should meet the following classifications, according to material. No guidance for European fire test performance is currently available, because there is no generally accepted test and classification procedure.

a.Non-plastic rooflights should meet the relevant classification in Table 4.1.

b.Plastic rooflights, if the limitations in Table 4.2 and Table 12.2 are observed, should be a minimum class D-s3, d2 rating. Otherwise they should meet the relevant classification in Table 4.1.

Special applications

4.8Any flexible membrane covering a structure, other than an air-supported structure, should comply with Appendix A of BS 7157.

4.9Guidance on the use of PTFE-based materials for tension-membrane roofs and structures is given in the BRE report BR 274.

Fire behaviour of insulating core panels used internally

4.10Insulating core panels consist of an inner core of insulation sandwiched between, and bonded to, a membrane, such as galvanised steel or aluminium.

Where they are used internally they can present particular problems with regard to fire spread and should meet all of the following conditions.

a.Panels should be sealed to prevent exposure of the core to a fire. This includes at joints and where services penetrate the panel.

b.In high fire risk areas, such as kitchens, places of special fire hazard, or in proximity to where hot works occur, only class A1 cored panels should be used.

c.Fixing systems for all panels should be designed to take account of the potential for the panel to delaminate. For instance, where panels are used to form a suspended ceiling, the fixing should pass through the panel and support it from the lower face.

Other controls on internal surface properties

4.11Guidance on the control of flame spread is given in the following sections.

a.Stairs and landings: Sections 2 and 3 (escape stairs) and Section 15 (firefighting shafts).

b.Exposed surfaces above fire-protecting suspended ceilings: Section 8.

c.Enclosures to above-ground drainage system pipes: Section 9.

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General provisions

4.12Thermoplastic materials that do not meet the classifications in Table 4.1 can be used as described in paragraphs 4.13 to 4.17. No guidance for European fire test performance is currently available, because there is no generally accepted test and classification procedure. Thermoplastic materials are defined in Appendix B, paragraph B11. Classifications used here are explained in paragraph B13.

Windows

4.13Thermoplastic material classified as a TP(a) rigid product may be used to glaze external windows to rooms, but not external windows to circulation spaces. Approved Document K includes guidance on the safety of glazing.

Rooflights

4.14In rooms and circulation spaces other than protected stairways, rooflights may be constructed of thermoplastic material if they comply with both of the following.

a.The lower surface is classified as TP(a) rigid or TP(b).

b.The size and location of the rooflights follow the limits in Table 4.2, Table 12.2 and Table 12.3.

Lighting diffusers

4.15The following paragraphs apply to lighting diffusers forming part of a ceiling. Diffusers may be part of a luminaire or used below sources of light. The following paragraphs do not apply to diffusers of light fittings attached to the soffit of a ceiling or suspended beneath a ceiling (Diagram 4.1).

4.16Diffusers constructed of thermoplastic material may be incorporated in ceilings to rooms and circulation spaces, but not to protected stairways, if both the following conditions are met.

a.Except for the upper surfaces of the thermoplastic panels, wall and ceiling surfaces exposed in the space above the suspended ceiling should comply with paragraph 4.1.

b.Diffusers should be classified as one of the following.

i.TP(a) rigid – no restrictions on their extent.

ii.TP(b) – limited in their extent (see Table 4.2 and Diagram 4.2).

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4.17A ceiling constructed from TP(a) flexible panels should meet the following conditions.

a.Have a maximum area of 5m².

b.Be supported on all sides.

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These sections deal with the following requirement from Part B of Schedule 1 to the Building Regulations 2010.

Intention

In the Secretary of State’s view, requirement B3 is met by achieving all of the following.

a.For defined periods, loadbearing elements of structure withstand the effects of fire without loss of stability.

b.Compartmentation of buildings by fire resisting construction elements.

c.Automatic fire suppression is provided where it is necessary.

d.Protection of openings in fire-separating elements to maintain continuity of the fire separation.

e.Inhibition of the unseen spread of fire and smoke in cavities, in order to reduce the risk of structural failure and spread of fire and smoke, where they pose a threat to the safety of people in and around the building.

The extent to which any of these measures are necessary is dependent on the use of the building and, in some cases, its size, and on the location of the elements of construction.

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Loadbearing elements of structure

Fire resistance standard

5.1Elements of structure such as structural frames, beams, columns, loadbearing walls (internal and external), floor structures and gallery structures should have, as a minimum, the fire resistance given in Appendix B, Table B3.

5.2If one element of structure supports or stabilises another, as a minimum the supporting element should have the same fire resistance as the other element.

5.3The following are excluded from the definition of ‘element of structure’.

a.A structure that supports only a roof, unless either of the following applies.

i.The roof performs the function of a floor, such as a roof terrace, or as a means of escape.

ii.The structure is essential for the stability of an external wall that needs to be fire resisting (e.g. to achieve compartmentation or for the purposes of preventing fire spread between buildings).

b.The lowest floor of the building.

c.External walls, such as curtain walls or other forms of cladding, which transmit only self weight and wind loads and do not transmit floor load.

Floors in loft conversions

5.4Where adding an additional storey to a two storey single family dwellinghouse, new floors should have a minimum REI 30 fire resistance. Any floor forming part of the enclosure to the circulation space between the loft conversion and the final exit should achieve a minimum rating of REI 30.

The existing first-storey construction should have a minimum rating of R 30. The fire performance may be reduced for integrity and insulation, when both of the following conditions are met.

a.Only one storey is added, containing a maximum of two habitable rooms.

b.The new storey has a maximum total area of 50m².

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Provision of compartmentation

5.5Dwellinghouses that are semi-detached or in terraces should be considered as separate buildings. Every wall separating the dwellinghouses should be constructed as a compartment wall (see paragraphs 5.8 to 5.12).

5.6If a garage is attached to or forms an integral part of a dwellinghouse, the garage should be separated from the rest of the dwellinghouse by fire resisting construction (minimum REI 30) (Diagram 5.1).

5.7Where a door is provided between a dwellinghouse and the garage (see Diagram 5.1), it should meet one of the following conditions.

a.The garage floor should be laid such that it falls away from the door to the outside, to allow fuel spills to flow away.

b.The door opening should be a minimum of 100mm above the level of the garage floor.

Construction of compartment walls and compartment floors

General provisions

5.8All compartment walls and compartment floors should achieve both of the following.

a.Form a complete barrier to fire between the compartments they separate.

b.Have the appropriate fire resistance, as given in Appendix B, Table B3 and Table B4.

5.9Timber beams, joists, purlins and rafters may be built into or carried through a masonry or concrete compartment wall if the openings for them are both of the following.

a.As small as practicable.

b.Fire-stopped.

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5.9If trussed rafters bridge the wall, failure of the truss due to a fire in one compartment should not cause failure of the truss in another compartment.

Compartment walls between buildings

5.10Adjoining buildings should only be separated by walls, not floors. Compartment walls common to two or more buildings should comply with both of the following.

a.Run the full height of the building in a continuous vertical plane.

b.Be continued through any roof space to the underside of the roof (see Diagram 5.2).

Junction of compartment wall with roof

5.11A compartment wall should achieve both of the following.

a.Meet the underside of the roof covering or deck, with fire-stopping to maintain the continuity of fire resistance.

b.Be continued across any eaves.

5.12To reduce the risk of fire spreading over the roof from one compartment to another, a 1500mm wide zone of the roof, either side of the wall, should have a covering classified as B_ROOF(t4), on a substrate or deck of a material rated class A2-s3, d2 or better, as set out in Diagram 5.2a.

Thermoplastic rooflights that, because of paragraph 12.7, are regarded as having a BROOF(t4) classification are not_ suitable for use in that zone.

5.13Materials achieving class B-s3, d2 or worse used as a substrate to the roof covering and any timber tiling battens, fully bedded in mortar or other suitable material for the width of the wall (Diagram 5.2b), may extend over the compartment wall in buildings that are a maximum of 15m high.

5.14Double-skinned insulated roof sheeting should incorporate a band of material rated class A2-s3, d2 or better, a minimum of 300mm in width, centred over the wall.

5.15As an alternative to the provisions of paragraphs 5.12 to 5.14, the compartment wall may extend through the roof for a minimum of either of the following (see Diagram 5.2c).

a.Where the height difference between the two roofs is less than 375mm, 375mm above the top surface of the adjoining roof covering.

b.200mm above the top surface of the adjoining roof covering where either of the following applies.

i.The height difference between the two roofs is 375mm or more.

ii.The roof coverings either side of the wall are of a material classified as B_ROOF(t4).

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5.16Cavities in the construction of a building provide a ready route for the spread of smoke and flame, which can present a greater danger as any spread is concealed. For the purpose of this document, a cavity is considered to be any concealed space.

Provision of cavity barriers

5.17To reduce the potential for fire spread, cavity barriers should be provided for both of the following.

a.To divide cavities.

b.To close the edges of cavities.

Cavity barriers should not be confused with fire-stopping details (Section 9).

5.18Cavity barriers should be provided at all of the following locations.

a.At the edges of cavities, including around openings (such as windows, doors and exit/entry points for services).

b.At the junction between an external cavity wall and every compartment floor and compartment wall.

c.At the junction between an internal cavity wall and every compartment floor, compartment wall or other wall or door assembly forming a fire resisting barrier.

This does not apply where a wall meets the conditions of Diagram 5.3.

5.19It is not appropriate to complete a line of compartment walls by fitting cavity barriers above them. The compartment wall should be extended to the underside of the floor or roof above.

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5.20Cavity barriers, tested from each side separately, should provide a minimum of both of the following:

a.30 minutes’ integrity (E 30)

b.15 minutes’ insulation (I 15).

They may be formed by a construction provided for another purpose if it achieves the same performance.

5.21Cavity barriers in a stud wall or partition, or provided around openings, may be formed of any of the following.

a.Steel, a minimum of 0.5mm thick.

b.Timber, a minimum of 38mm thick.

c.Polythene-sleeved mineral wool, or mineral wool slab, under compression when installed in the cavity.

d.Calcium silicate, cement-based or gypsum-based boards, a minimum of 12mm thick.

These do not necessarily achieve the performance specified in paragraph 5.20.

5.22Cavity barriers should be tightly fitted to a rigid construction and mechanically fixed in position. If this is not possible (e.g. where a cavity barrier joins to slates, tiles, corrugated sheeting or similar materials) the junction should be fire-stopped.

5.23Cavity barriers should be fixed so their performance is unlikely to be made ineffective by any of the following.

a.Movement of the building due to subsidence, shrinkage or temperature change, and movement of the external envelope due to wind.

b.During a fire, collapse of services penetrating the cavity barriers, either by the failure of the supporting system or through degradation of the service itself (e.g. by melting or burning).

c.During a fire, failure of the cavity barrier fixings. (In roof spaces, where cavity barriers are fixed to roof members, there is no expectation of fire resistance from roof members provided for the purpose of support.)

d.During a fire, failure of any material or construction to which cavity barriers abut. (For example, a suspended ceiling that continues over a fire resisting wall or partition collapses, and the cavity barrier fails prematurely because the ceiling was not designed to provide a minimum fire resistance of EI 30.)

Openings in cavity barriers

5.24Openings should be limited to the following.

a.Fire doorsets with a minimum E 30 rating, fitted in accordance with Appendix C.

b.The passage of pipes that follow the provisions in Section 9.

c.The passage of cables or conduits containing one or more cables.

d.Openings fitted with a suitably mounted and appropriate fire damper.

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e.Ducts that are either of the following.

i.Fire resisting (minimum E 30).

ii.Fitted with a suitably mounted and appropriate fire damper where they pass through the cavity barrier.

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Fire resistance standard

6.1Elements of structure such as structural frames, beams, columns, loadbearing walls (internal and external), floor structures and gallery structures should have, as a minimum, the fire resistance given in Appendix B, Table B3.

6.2The following are excluded from the definition of ‘element of structure’.

a.A structure that supports only a roof, unless either of the following applies.

i.The roof performs the function of a floor, such as for parking vehicles, or as a means of escape.

ii.The structure is essential for the stability of an external wall that needs to be fire resisting (e.g. to achieve compartmentation or for the purposes of preventing fire spread between buildings).

b.The lowest floor of the building.

c.A platform floor.

d.External walls, such as curtain walls or other forms of cladding, which transmit only self weight and wind loads and do not transmit floor load.

Additional guidance

6.3If a loadbearing wall is any of the following, guidance in other sections may also apply.

a.A compartment wall (including a wall common to two buildings): Section 7.

b.Enclosing a place of special fire hazard: Section 7.

c.Protecting a means of escape: Sections 2 and 3.

d.An external wall: Sections 10 and 11.

e.Enclosing a firefighting shaft: Section 15.

6.4If a floor is also a compartment floor, see Section 7.

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6.5Where an existing dwellinghouse or other building is converted into flats, a review of the existing construction should be carried out. Retained timber floors may make it difficult to meet the relevant provisions for fire resistance.

6.6In a converted building with a maximum of three storeys, a minimum REI 30 fire resistance could be accepted for elements of structure if the means of escape conform to the provisions of Section 3.

6.7In a converted building with four or more storeys, the full standard of fire resistance given in Appendix B is necessary.

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Provision of compartmentation

7.1All of the following should be provided as compartment walls and compartment floors and should have, as a minimum, the fire resistance given in Appendix B, Table B3.

a.Any floor (unless it is within a flat, i.e. between one storey and another within one individual dwelling).

b.Any wall separating a flat from another part of the building.

c.Any wall enclosing a refuse storage chamber.

d.Any wall common to two or more buildings.

Places of special fire hazard

7.2Fire resisting construction enclosing these places should achieve minimum REI 30. These walls and floors are not compartment walls and compartment floors.

7.3Parts of a building occupied mainly for different purposes should be separated from one another by compartment walls and/or compartment floors. Compartmentation is not needed if one of the different purposes is ancillary to the other. See paragraphs 0.18 and 0.19.

Sprinklers

7.4Blocks of flats with a top storey more than 11m above ground level (see Diagram D6) should be fitted with a sprinkler system throughout the building in accordance with Appendix E.

Construction of compartment walls and compartment floors

General provisions

7.5All compartment walls and compartment floors should achieve both of the following.

a.Form a complete barrier to fire between the compartments they separate.

b.Have the appropriate fire resistance, as given in Appendix B, Tables B3 and B4.

7.6Timber beams, joists, purlins and rafters may be built into or carried through a masonry or concrete compartment wall if the openings for them are both of the following.

a.As small as practicable.

b.Fire-stopped.

If trussed rafters bridge the wall, failure of the truss due to a fire in one compartment should not cause failure of the truss in another compartment.

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7.7Where services could provide a source of ignition, the risk of fire developing and spreading into adjacent compartments should be controlled.

Compartment walls between buildings

7.8Adjoining buildings should only be separated by walls, not floors. Compartment walls common to two or more buildings should comply with both of the following.

a.Run the full height of the building in a continuous vertical plane.

b.Be continued through any roof space to the underside of the roof (see Diagram 5.2).

Separated parts of buildings

7.9Compartment walls forming a separated part of a building should run the full height of the building in a continuous vertical plane.

Separated parts can be assessed independently to determine the appropriate standard of fire resistance in each. The two separated parts can have different standards of fire resistance.

Other compartment walls

7.10Compartment walls not described in paragraphs 7.8 and 7.9 should run the full height of the storey in which they are situated.

7.11Compartment walls in a top storey beneath a roof should be continued through the roof space.

Junction of compartment wall or compartment floor with other walls

7.12At the junction with another compartment wall or an external wall, the fire resistance of the compartmentation should be maintained. Fire-stopping that meets the provisions in paragraphs 9.24 to 9.29 should be provided.

7.13At the junction of a compartment floor and an external wall with no fire resistance, the external wall should be restrained at floor level. The restraint should reduce movement of the wall away from the floor if exposed to fire.

7.14Compartment walls should be able to accommodate deflection of the floor, when exposed to fire, by either of the following means.

a.Between the wall and floor, provide a head detail that is capable of maintaining its integrity while deforming.

b.Design the wall so it maintains its integrity by resisting the additional vertical load from the floor above.

Where compartment walls are located within the middle half of a floor between vertical supports, the deflection may be assumed to be 40mm unless a smaller value can be justified by assessment. Outside this area, the limit can be reduced linearly to zero at the supports.

For steel beams that do not have the required fire resistance, reference should be made to SCI Publication P288.

Junction of compartment wall with roof

7.15The requirements are the same as for dwellinghouses, detailed in paragraphs 5.11 and 5.12.

7.16Materials achieving class B-s3, d2 or worse used as a substrate to the roof covering and any timber tiling battens, fully bedded in mortar or other suitable material for the width of the wall (Diagram 5.2b), may extend over the compartment wall in buildings that are both of the following.

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a.A maximum of 15m high.

b.In one of the following purpose groups.

i.All residential purpose groups (purpose groups 1 and 2) other than ‘residential (institutional)’ (purpose group 2(a)).

ii.‘Office’ (purpose group 3).

iii.‘Assembly and recreation’ (purpose group 5).

7.17Double-skinned insulated roof sheeting with a thermoplastic core should incorporate a band of material rated class A2-s3, d2 or better, a minimum of 300mm in width, centred over the wall.

7.18As an alternative to the provisions of paragraph 7.16 or 7.17, the compartment wall may extend through the roof for a minimum of either of the following (see Diagram 5.2c).

a.Where the height difference between the two roofs is less than 375mm, 375mm above the top surface of the adjoining roof covering.

b.200mm above the top surface of the adjoining roof covering where either of the following applies.

i.The height difference between the two roofs is 375mm or more.

ii.The roof coverings either side of the wall are of a material classified as B_ROOF(t4).

Openings in compartmentation

Openings in compartment walls separating buildings or occupancies

7.19Openings in a compartment wall common to two or more buildings should be limited to those for either of the following.

a.A fire doorset providing a means of escape, which has the same fire resistance as the wall and is fitted in accordance with the provisions in Appendix C.

b.The passage of a pipe that complies with the provisions in Section 9.

Openings in other compartment walls, or in compartment floors

7.20Openings should be limited to those for any of the following.

a.Fire doorsets of the appropriate fire resistance, fitted in accordance with the provisions in Appendix C.

b.Pipes, ventilation ducts, service cables, chimneys, appliance ventilation ducts or ducts encasing one or more flue pipes, complying with the provisions in Section 9.

c.Refuse chutes of class A1 construction.

d.Atria designed in accordance with Annexes B and C of BS 9999.

e.Protected shafts that conform to the provisions in the following paragraphs.

Protected shafts

7.21Stairs and service shafts connecting compartments should be protected to restrict the spread of fire between the compartments. These are called protected shafts. Walls or floors surrounding a protected shaft are considered to be compartment walls or compartment floors.

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7.22Any stair or other shaft passing directly from one compartment to another should be enclosed in a protected shaft. Protected shafts should be used for the following only, but may also include sanitary accommodation and washrooms.

a.Stairs.

b.Lifts.

c.Escalators.

d.Chutes.

e.Ducts.

f.Pipes.

g.Additional provisions apply for both of the following.

i.Protected shafts that are protected stairways: Sections 2 to 4.

ii.Stairs that are also firefighting stairs: Section 15.

Construction of protected shafts

7.23The construction enclosing a protected shaft (Diagram 7.1) should do all of the following.

a.Form a complete barrier to fire between the compartments connected by the shaft.

b.Have the appropriate fire resistance given in Appendix B, Table B3, except for uninsulated glazed screens that meet the provisions of paragraph 7.24.

c.Satisfy the provisions for ventilation and the treatment of openings in paragraphs 7.28 and 7.29.

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7.24An uninsulated glazed screen may be incorporated in the enclosure to a protected shaft between a stair and a lobby or corridor entered from the stair. The enclosure must conform to Diagram 7.2 and meet all of the following conditions.

a.The standard of fire resistance required for the protected stairway is not more than REI 60.

b.The glazed screen complies with the following.

i.It achieves a minimum rating of E 30.

ii.It complies with the guidance on limits on areas of uninsulated glazing in Appendix B, Table B5.

c.The lobby or corridor is enclosed with fire resisting construction achieving a minimum rating of REI 30.

7.25Where the measures in Diagram 7.2 are not provided, then both of the following apply.

a.The enclosing walls should comply with Appendix B, Table B3.

b.The doors should comply with Appendix B, Table B5.

Pipes for oil or gas and ventilation ducts in protected shafts

7.26A protected shaft containing a protected stairway and/or a lift should not also contain either of the following.

a.A pipe that conveys oil, other than in the mechanism of a hydraulic lift.

b.A ventilating duct. Two exceptions are as follows.

i.A duct provided for pressurising the protected stairway to keep it smoke free.

ii.A duct provided only to ventilate the protected stairway.

A pipe that is completely separated from a protected shaft by fire resisting construction is not considered to be contained within that shaft.

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7.27In a protected shaft, any pipe carrying natural gas or LPG should be both of the following.

a.Of screwed steel or all-welded steel construction.

b.Installed in accordance with both of the following.

i.The Pipelines Safety Regulations 1996.

ii.The Gas Safety (Installation and Use) Regulations 1998.

Ventilation of protected shafts conveying gas

7.28A protected shaft conveying piped flammable gas should be ventilated direct to the outside air, by ventilation openings at high and low level in the shaft.

Any extension of the storey floor into the protected shaft should not compromise the free movement of air throughout the entire length of the shaft.

Guidance on shafts conveying piped flammable gas, including the size of ventilation openings, is given in BS 8313.

Openings into protected shafts

7.29The external wall of a protected shaft does not normally need to have fire resistance. Situations where there are provisions are given in paragraph 3.63 (external walls of protected stairways, which may also be protected shafts) and paragraphs 15.8 to 15.11 (firefighting shafts).

Openings in other parts of the enclosure to a protected shaft should be limited to the following.

a.If a wall common to two or more buildings forms part of the enclosure, only the following openings should be made in that wall.

i.A fire doorset providing a means of escape, which has the same fire resistance as the wall and is fitted in accordance with the provisions in Appendix C.

ii.The passage of a pipe that meets the provisions in Section 9.

b.Other parts of the enclosure (other than an external wall) should only have openings for any of the following.

i.Fire doorsets of the appropriate fire resistance, fitted in accordance with the provisions in Appendix C.

ii.The passage of pipes which meet the provisions in Section 9.

iii.Inlets to, outlets from and openings for a ventilation duct (if the shaft contains or serves as a ventilating duct), meeting the provisions in Section 9.

iv.The passage of lift cables into a lift machine room (if the shaft contains a lift). If the machine room is at the bottom of the shaft, the openings should be as small as practicable.

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8.1Cavities in the construction of a building provide a ready route for the spread of smoke and flame, which can present a greater danger as any spread is concealed. For the purpose of this document, a cavity is considered to be any concealed space.

Provision of cavity barriers

8.2To reduce the potential for fire spread, cavity barriers should be provided for both of the following.

a.To divide cavities.

b.To close the edges of cavities.

See Diagram 8.1. Cavity barriers should not be confused with fire-stopping details (Section 9).

Pathways around fire-separating elements

Junctions and edges of cavities

8.3Cavity barriers should be provided at all of the following locations.

a.At the edges of cavities, including around openings (such as windows, doors and exit/entry points for services).

b.At the junction between an external cavity wall and every compartment floor and compartment wall.

c.At the junction between an internal cavity wall and every compartment floor, compartment wall or other wall or door assembly forming a fire resisting barrier.

This does not apply where a wall meets the conditions of Diagram 8.2.

8.4It is not appropriate to complete a line of compartment walls by fitting cavity barriers above them. The compartment walls should extend to the underside of the floor or roof above.

Protected escape routes

8.5If the fire resisting construction of a protected escape route is either of the following.

a.Not carried to full storey height.

b.At the top storey, not carried to the underside of the roof covering.

Then the cavity above or below the fire resisting construction should be either of the following.

i.Fitted with cavity barriers on the line of the enclosure.

ii.For cavities above the fire resisting construction, enclosed on the lower side by a fire resisting ceiling (minimum EI 30) that extends throughout the building, compartment or separated part (see Diagram 8.3).

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Cavities affecting alternative escape routes

8.6In divided corridors (paragraph 3.25 and following) with cavities, fire-stopping should be provided to prevent alternative escape routes being affected by fire and/or smoke.

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8.7Cavity barriers are not required between double-skinned corrugated or profiled insulated roof sheeting, if the sheeting complies with all of the following.

a.The sheeting is rated class A2-s3, d2 or better.

b.Both surfaces of the insulating layer are rated class C-s3, d2 or better.

c.Both surfaces of the insulating layer make contact with the inner and outer skins of cladding (Diagram 8.4).

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Construction and fixings for cavity barriers

8.8Cavity barriers, tested from each side separately, should provide a minimum of both of the following:

a.30 minutes’ integrity (E 30)

b.15 minutes’ insulation (I 15).

They may be formed by a construction provided for another purpose if it achieves the same performance.

8.9Cavity barriers should meet the requirements set out in paragraphs 5.21 to 5.24.

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Introduction

9.1Every joint, imperfect fit and opening for services through a fire-separating element should be sealed with fire-stopping to ensure that the fire resistance of the element is not impaired. Fire-stopping delays the spread of fire and, generally, the spread of smoke as well.

Openings for pipes

9.2Pipes passing through a fire-separating element, unless in a protected shaft, should meet one of the alternatives A, B or C below.

Alternative A: Proprietary seals (any pipe diameter)

9.3Provide a proprietary, tested sealing system that will maintain the fire resistance of the wall, floor or cavity barrier.

Alternative B: Pipes with a restricted diameter

9.4Where a proprietary sealing system is not used, fire-stop around the pipe, keeping the opening for the pipe as small as possible. The nominal internal diameter of the pipe should not exceed the relevant dimension given in Table 9.1. The diameter given in Table 9.1 for pipes in specification (b) used in situation 2 or 3 assumes that the pipes are part of an above-ground drainage system and are enclosed as shown in Diagram 9.1. If they are not, the smaller diameter given for situation 5 should be used.

Alternative C: Sleeving

9.5A pipe with a maximum nominal internal diameter of 160mm may be used with a sleeve made out of a high melting point metal, as shown in Diagram 9.2, if the pipe is made of one of the following.

a.Lead.

b.Aluminium.

c.Aluminium alloy.

d.Fibre-cement.

e.uPVC (pipes should also comply with either BS 4514 or BS 5255).

A high melting point metal means any metal (such as cast iron, copper or steel) which, if exposed to a temperature of 800°C, will not soften or fracture to the extent that flame or hot gas will pass through the wall of the pipe.

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Mechanical ventilation and air-conditioning systems

General provisions

9.6Ductwork should not help to transfer fire and smoke through the building. Terminals of exhaust points should be sited away from final exits, cladding or roofing materials achieving class B-s3, d2 or worse and openings into the building.

9.7Ventilation ducts supplying or extracting air directly to or from a protected stairway should not also serve other areas. A separate ventilation system should be provided for each protected stairway.

9.8A fire and smoke damper should be provided where ductwork enters or leaves each section of the protected escape route it serves. It should be operated by a smoke detector or suitable fire detection system. Fire and smoke dampers should close when smoke is detected. Alternatively, the methods set out in paragraphs 9.16 and 9.17 and Diagrams 9.3 and 9.4 may be followed.

9.9In a system that recirculates air, smoke detectors should be fitted in the extract ductwork before both of the following.

a.The point where recirculated air is separated from air to be discharged to the outside.

b.Any filters or other air cleaning equipment.

When smoke is detected, detectors should do one of the following.

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i.Cause the system to immediately shut down.

ii.Switch the ventilation system from recirculating mode to extraction to divert smoke to outside the building.

9.10In mixed use buildings, non-domestic kitchens, car parks and plant rooms should have separate and independent extraction systems. Extracted air should not be recirculated.

9.11Under fire conditions, ventilation and air-conditioning systems should be compatible with smoke control systems and need to be considered in their respective design.

Ventilation ducts and flues passing through fire-separating elements

General provisions

9.12If air handling ducts pass through fire-separating elements, the fire performance of the elements should be maintained using one or more of the following four methods. In most ductwork systems, a combination of the four methods is best.

a.Method 1 – thermally activated fire dampers.

b.Method 2 – fire resisting enclosures.

c.Method 3 – protection using fire resisting ductwork.

d.Method 4 – automatically activated fire and smoke dampers triggered by smoke detectors.

9.13Further information on fire resisting ductwork is given in the ASFP Blue Book.

Flats and dwellings

9.14Where ducts pass between fire-separating elements to serve multiple flats or dwellings, fire dampers or fire and smoke dampers should be actuated by both of the following.

a.Smoke detector-controlled automatic release mechanisms.

b.Thermally actuated devices.

Kitchen extract

9.15Methods 1 and 4 should not be used for extract ductwork serving kitchens. The likely build-up of grease within the duct can adversely affect dampers.

Ducts passing through protected escape routes

9.16Method 1 should not be used for extract ductwork passing through the enclosures of protected escape routes (Diagrams 9.3 and 9.4), as large volumes of smoke can pass thermal devices without triggering them.

9.17An ES classified fire and smoke damper which is activated by a suitable fire detection system (method 4) may also be used for protected escape routes.

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9.18Both fire dampers and fire and smoke dampers should be all of the following.

a.Sited within the thickness of the fire-separating elements.

b.Securely fixed.

c.Sited such that, in a fire, expansion of the ductwork would not push the fire damper through the structure.

9.19Access to the fire damper and its actuating mechanism should be provided for inspection, testing and maintenance.

9.20Fire dampers should meet both of the following conditions.

a.Conform to BS EN 15650.

b.Have a minimum E classification of 60 minutes or to match the integrity rating of the fire resisting elements, whichever is higher.

9.21Fire and smoke dampers should meet both of the following conditions.

a.Conform to BS EN 15650.

b.Have a minimum ES classification of 60 minutes or to match the integrity rating of the fire resisting elements, whichever is higher.

9.22Smoke detectors should be sited so as to prevent the spread of smoke as early as practicable by activating the fire and smoke dampers. Smoke detectors and automatic release mechanisms used to activate fire dampers and/or fire and smoke dampers should conform to BS EN 54-7 and BS 5839-3 respectively.

Further information on fire dampers and/or fire and smoke dampers is given in the ASFP Grey Book.

Flues, etc.

9.23The wall of a flue, duct containing flues or appliance ventilation duct(s) should have a fire resistance (REI) that is at least half of any compartment wall or compartment floor it passes through or is built into (Diagram 9.5).

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9.24In addition to any other provisions in this section, both of the following conditions should be met.

a.Joints between fire-separating elements should be fire-stopped.

b.Openings through a fire resisting element for pipes, ducts, conduits or cable should be all of the following.

i.As few as possible.

ii.As small as practicable.

iii.Fire-stopped (allowing thermal movement in the case of a pipe or duct).

9.25Materials used for fire-stopping should be reinforced with (or supported by) materials rated class A2-s3, d2 or better to prevent displacement in both of the following cases.

a.Where the unsupported span is greater than 100mm.

b.Where non-rigid materials are used (unless subjected to appropriate fire resistance testing to show their suitability).

9.26Proprietary, tested fire-stopping and sealing systems are available and may be used. Different materials suit different situations and not all are suitable in every situation.

9.27Other fire-stopping materials include the following.

a.Cement mortar.

b.Gypsum-based plaster.

c.Cement-based or gypsum-based vermiculite/perlite mixes.

d.Glass fibre, crushed rock, blast furnace slag or ceramic-based products (with or without resin binders).

e.Intumescent mastics.

These may be used in situations appropriate to the particular material. Not all materials will be suitable in every situation.

9.28Guidance on the design, installation and maintenance of measures to contain fires or slow their spread is given in Ensuring Best Practice for Passive Fire Protection in Buildings produced by the Association for Specialist Fire Protection (ASFP).

9.29Further information on generic systems, their suitability for different applications and guidance on test methods, is given in the ASFP Red Book.

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These sections deal with the following requirement from Part B of Schedule 1 to the Building Regulations 2010. Section 10 also refers to regulation 7(2) of the Building Regulations 2010. Guidance on regulation 7(1) can be found in Approved Document 7.

Regulation

Regulation 7 – Materials and workmanship

(1)Building work shall be carried out—

(a)with adequate and proper materials which—

(i)are appropriate for the circumstances in which they are used,

(ii)are adequately mixed or prepared, and

(iii)are applied, used or fixed so as adequately to perform the functions for which they are designed; and

(b)in a workmanlike manner.

(1A)Building work shall be carried out so that relevant metal composite material does not become part of an external wall, or specified attachment, of any building.

(2)Subject to paragraph (3), building work shall be carried out so that materials which become part of an external wall, or specified attachment, of a relevant building are of European Classification A2-s1, d0 or A1 (classified in accordance with the reaction to fire classification).

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Resisting fire spread over external walls

The external envelope of a building should not contribute to undue fire spread from one part of a building to another part. This intention can be met by constructing external walls so that both of the following are satisfied.

a.The risk of ignition by an external source to the outside surface of the building and spread of fire over the outside surface is restricted.

b.The materials used to construct external walls, and attachments to them, and how they are assembled do not contribute to the rate of fire spread up the outside of the building.

The extent to which this is necessary depends on the height and use of the building.

Resisting fire spread from one building to another

The external envelope of a building should not provide a medium for undue fire spread to adjacent buildings or be readily ignited by fires in adjacent buildings. This intention can be met by constructing external walls so that all of the following are satisfied.

a.The risk of ignition by an external source to the outside surface of the building is restricted.

b.The amount of thermal radiation that falls on a neighbouring building from window openings and other unprotected areas in the building on fire is not enough to start a fire in the other building.

c.Flame spread over the roof and/or fire penetration from external sources through the roof is restricted.

The extent to which this is necessary depends on the use of the building and its position in relation to adjacent buildings and therefore the site boundary.

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Introduction

10.1The external wall of a building should not provide a medium for fire spread if that is likely to be a risk to health and safety. Combustible materials and cavities in external walls and attachments to them can present such a risk, particularly in tall buildings. The guidance in this section is designed to reduce the risk of fire spread as well as the risk of ignition from flames coming from adjacent buildings.

Fire resistance

10.2This section provides guidance on resisting fire spread over external walls; however, it does not deal with fire resistance of external walls. An external wall may need fire resistance to meet the provisions of Section 3 (Means of escape – flats), Section 6 (Loadbearing elements of structure – flats), Section 11 (Resisting fire spread from one building to another) or Section 15 (Access to buildings for firefighting personnel – flats).

Combustibility of external walls

10.3The external walls of buildings other than those described in regulation 7(4) of the Building Regulations should achieve either of the following.

a.Follow the provisions given in paragraphs 10.5 to 10.9, which provide guidance on all of the following.

i.External surfaces.

ii.Materials and products.

iii.Cavities and cavity barriers.

b.Meet the performance criteria given in BRE report BR 135 for external walls using full-scale test data from BS 8414-1 or BS 8414-2.

10.4In relation to buildings of any height or use, consideration should be given to the choice of materials (including their extent and arrangement) used for the external wall, or attachments to the wall (e.g. balconies, etc.), to reduce the risk of fire spread over the wall.

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10.5The external surfaces (i.e. outermost external material) of external walls should comply with the provisions in Table 10.1. The provisions in Table 10.1 apply to each wall individually in relation to its proximity to the relevant boundary.

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10.6In a building with a storey 18m or more in height (see Diagram D6 in Appendix D) any insulation product, filler material (such as the core materials of metal composite panels, sandwich panels and window spandrel panels but not including gaskets, sealants and similar) etc. used in the construction of an external wall should be class A2-s3, d2 or better (see Appendix B). This restriction does not apply to masonry cavity wall construction which complies with Diagram 8.2 in Section 8. Where regulation 7(2) applies, that regulation prevails over all the provisions in this paragraph.

10.7In buildings that include a ‘residential’ purpose (purpose groups 1 and 2) with a storey 11m or more in height (see Diagram D6 in Appendix D) any insulation product, filler material (such as the core materials of metal composite panels, sandwich panels and window spandrel panels but not including gaskets, sealants and similar) etc. used in the construction of an external wall should be class A2-s1, d0 or better (see Appendix B). This restriction does not apply to masonry cavity wall construction which complies with Diagram 8.2 in Section 8. Where regulation 7(2) applies, that regulation prevails over all the provisions in this paragraph.

10.8Best practice guidance for green walls (also called living walls) can be found in Fire Performance of Green Roofs and Walls, published by the Department for Communities and Local Government. Where regulation 7(2) applies, that regulation prevails over all the provisions in this paragraph.

Cavities and cavity barriers

10.9Cavity barriers should be provided in accordance with Section 5 in dwellinghouses and Section 8 in flats.

Balconies

10.10In buildings that include a ‘residential’ purpose (purpose groups 1 and 2) with a storey 11m or more in height (see Diagram D6 in Appendix D) balconies should meet either of the following conditions.

a.Only contain materials achieving class A1 or A2-s1, d0, except for any of the following.

i.Cavity trays when used between two leaves of masonry.

ii.Intumescent and fire-stopping materials where the inclusion of the materials is necessary to meet the requirements of Part B of Schedule 1 to the Building Regulations 2010.

iii.Membranes.

iv.Seals, gaskets, fixings, sealants and backer rods.

v.Thermal break materials where the inclusion of the materials is necessary to meet the thermal bridging requirements of Part L of Schedule 1 to the Building Regulations 2010.

vi.Any material achieving class A1fl or A2fl-s1 when it forms the top horizontal floor layer of a balcony and is provided with an imperforate substrate under it which extends to the full size of the class A1fl or A2fl-s1 material.

vii.Electrical installations.

viii.Fibre optic cables.

b.Achieve both of the following conditions.

i.Have an imperforate soffit which extends to the full area of the balcony, achieves a minimum REI 30 rating and is constructed of materials achieving class A2-s1, d0 or better.

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ii.Materials achieving class B-s1, d0 or worse extending beyond the boundary of a single compartment should include a band of material rated class A2-s1, d0 or better, a minimum of 300mm in width centred on that boundary line.

Where regulation 7(2) applies, that regulation prevails over all the provisions in this paragraph.

Metal composite materials

10.11Regulation 7(1A) prohibits the use of relevant metal composite materials in the external walls, and specified attachments, of all buildings of any height.

10.12Relevant metal composite materials are defined (in regulation 2(6)(c)) as any panel or sheet, having a thickness of no more than 10mm which is composed of a number of layers two or more of which are made of metal, alloy or metal compound and one or more of which is a substantial layer made of a material having a gross calorific value of more than 35MJ/kg when tested in accordance with BS EN ISO 1716. A substantial layer is defined as a layer which is at least 1mm thick or has a mass per unit area of at least 1kg/m².

Regulation 7(2) and requirement B4

Materials

10.13Regulation 7(1)(a) requires that materials used in building work are appropriate for the circumstances in which they are used. Regulation 7(2) sets requirements in respect of external walls and specified attachments in relevant buildings.

10.14Regulation 7(2) applies to any building with a storey at least 18m above ground level (as measured in accordance with Diagram D6 in Appendix D) and which contains one or more dwellings; an institution; or a room for residential purposes. It requires that all materials which become part of an external wall or specified attachment achieve class A2-s1, d0 or class A1 in accordance with BS EN 13501-1, other than those exempted by regulation 7(3).

10.15External walls and specified attachments are defined in regulation 2(6) and these definitions include any parts of the external wall as well as balconies, solar panels and solar shading.

10.16Regulation 7(3) provides an exemption for certain components found in external walls and specified attachments.

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10.17Regulations 5(k) and 6(3) provide that, where the use of a building is changed such that the building becomes a building described in regulation 7(4), the construction of the external walls, and specified attachments, must be investigated and, where necessary, work must be carried out to ensure they only contain materials achieving class A2-s1, d0 or class A1, other than those exempted by regulation 7(3).

Solar shading devices

10.18Regulation 7(2) requires that the curtain and or slats of solar shading devices in a relevant building (as defined in regulation 7(4)) achieve class A1 or A2-s1, d0. The curtain of solar shading devices cannot be classified as a membrane in accordance with regulation 7(3).

10.19Solar shading devices installed up to 4.5m above ground level are not required to meet the requirements of regulation 7(2).

Additional considerations

10.20The provisions of regulation 7 apply in addition to requirement B4. Therefore, for buildings described in regulation 7(4), the potential impact of any products incorporated into or onto the external walls and specified attachments should be carefully considered with regard to their number, size, orientation and position.

10.21Particular attention is drawn to the following points.

a.Membranes used as part of the external wall construction above ground level should achieve a minimum of class B-s3, d0. Roofing membranes do not need to achieve a minimum of class A2-s1, d0 when used as part of a roof connecting to an external wall.

b.Internal linings should comply with the guidance provided in Section 4.

c.Any part of a roof should achieve the minimum performance as detailed in Section 12.

d.As per regulation 7(3), window frames and glass (including laminated glass) are exempted from regulation 7(2). Window spandrel panels and infill panels must comply with regulation 7(2).

e.Thermal breaks are small elements used as part of the external wall construction to restrict thermal bridging. There is no minimum performance for these materials. However, they should not span two compartments and should be limited in size to the minimum required to restrict the thermal bridging (the principal insulation layer is not to be regarded as a thermal break).

f.Regulation 7(2) only applies to specified attachments. Shop front signs and similar attachments are not covered by the requirements of regulation 7(2), although attention is drawn to paragraph 10.21g.

g.While regulation 7(2) applies to materials which become part of an external wall or specified attachment, consideration should be given to other attachments to the wall which could impact on the risk of fire spread over the wall.

h.Any material achieving class A1fl or A2fl-s1 in accordance with BS EN 13501-1 is exempted when it meets both of the following conditions.

i.It forms the top horizontal floor layer of a balcony.

ii.It is provided with an imperforate substrate under which it extends to the full size of the class A1fl or A2fl-s1 material.

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Introduction

11.1The following assumptions enable a reasonable standard of resistance to the spread of fire to be specified.

a.The size of a fire depends on the compartmentation within the building. A fire may involve a complete compartment, but will not spread to other compartments.

b.The intensity of a fire is related to the building use, but can be moderated by a sprinkler system.

c.Fires in ‘residential’ and ‘assembly and recreation’ buildings (purpose groups 1, 2 and 5) represent a greater risk to life.

d.A building on the far side of the relevant boundary meets both of the following conditions.

i.Has a similar elevation to the one in question.

ii.Is the same distance as the one in question from the common boundary.

e.The radiated heat passing through any part of the fire resisting external wall may be discounted.

11.2Where regulation 7(2) applies, that regulation prevails over the provisions within this section.

11.3If a reduced separation distance between buildings, or increased amount of unprotected area, is required, smaller compartments should be considered.

Boundaries

11.4The fire resistance of a wall depends on its distance from the relevant boundary (see Diagram 11.1). Separation distances are measured to boundaries to ensure that the location and design of buildings on adjoining sites have no influence on the building under consideration.

11.5The boundary that a wall faces is the relevant boundary (Diagram 11.2). It may be one of the following.

a.The site boundary.

b.The centre line of a space where further development is unlikely, such as a road, railway, canal or river.

c.An assumed notional boundary between two buildings on the same site (Diagram 11.3) where either of the following conditions is met.

i.One or both of the buildings are in the ‘residential’ or ‘assembly and recreation’ purpose groups (purpose group 1, 2 or 5).

ii.The buildings will be operated/managed by different organisations.

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11.6Parts of an external wall with less fire resistance than the appropriate amount given in Appendix B, Table B4, are called unprotected areas.

11.7Where a fire resisting external wall has an external surface material that is worse than class B-s3, d2 and is more than 1mm thick, that part of the wall should be classified as an unprotected area equating to half its area (Diagram 11.4).

External walls on, and within 1000mm of, the relevant boundary

11.8Unprotected areas should meet the conditions in Diagram 11.5, and the rest of the wall should be fire resisting from both sides.

External surface materials facing the boundary should be class B-s3, d2 or better.

External walls 1000mm or more from the relevant boundary

11.9Unprotected areas should not exceed the result given by one of the methods in paragraph 11.16, and the rest of the wall (if any) should be fire resisting but only from the inside of the building.

External walls of protected stairways

11.10Exclude external walls of stairways in a protected shaft when assessing unprotected areas (see Diagram 11.5).

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11.11In an otherwise protected wall, small unprotected areas may be ignored where they meet the conditions in Diagram 11.5.

Canopies

11.12Where both of the following apply, separation distances may be determined from the wall rather than from the edge of the canopy (Diagram 11.6).

a.The canopy is attached to the side of a building.

b.The edges of the canopy are a minimum of 2m from the relevant boundary.

Canopies that fall within class 6 or class 7 of Schedule 2 to the regulations (Exempt Buildings and Work) are exempt from the Building Regulations.

11.13Space separation may be disregarded if a canopy is all of the following.

a.Free-standing.

b.Above a limited risk or controlled hazard.

c.A minimum of 1000mm from the relevant boundary.

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Roofs

11.14Roofs with a pitch of more than 70 degrees to the horizontal should be assessed in accordance with this section. Vertical parts of a pitched roof, such as dormer windows, should be included only if the slope of the roof exceeds 70 degrees.

It is a matter of judgement whether a continuous run of dormer windows that occupies most of a steeply pitched roof should be treated as a wall rather than a roof.

Portal frames

11.15Portal frames are often used in single storey industrial and commercial buildings where there may be no need for fire resistance of the structure (requirement B3). However, where a portal framed building is near a relevant boundary, the external wall near the boundary may need fire resistance to restrict the spread of fire between buildings. It is generally accepted that a portal frame acts as a single structural element because of the moment-resisting connections used, especially at the column/rafter joints. Thus, in cases where the external wall of the building cannot be wholly unprotected, the rafter members of the frame, as well as the column members, may need to be fire protected. The design method for this is set out in SCI Publication P313.

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a.The column members are fixed rigidly to a base of sufficient size and depth to resist overturning.

b.There is brick, block or concrete protection to the columns up to a protected ring beam providing lateral support.

c.There is some form of roof venting to give early heat release. (The roof venting could be, for example, PVC rooflights covering some 10% of the floor area and evenly spaced over the floor area.)

Methods for calculating acceptable unprotected area

11.16Two simple methods are given for calculating the acceptable amount of unprotected area in an external wall that is a minimum of 1000mm from any point on the relevant boundary. More precise methods are described in BRE report BR 187 and may be used instead. When using BR 187 the following radiation intensity at each unprotected area should be assumed.

a.84kW/m² if the purpose group of the building is ‘residential’ (purpose groups 1 or 2), ‘office’ (purpose group 3) or ‘assembly and recreation’ (purpose group 5) or if the building is an open-sided multi-storey car park (purpose group 7(b)).

b.168kW/m² if the purpose group of the building is ‘shop and commercial’ (purpose group 4), ‘industrial’ (purpose group 6) or ‘storage and other non-residential’ (purpose group 7(a)).

Method 1

11.17This method applies to small buildings intended to be used for blocks of flats or dwellinghouses.

11.18The building should not exceed three storeys in height (excluding basements) or 24m in length. Each side of the building should meet the limits stated in Diagram 11.7. Any small unprotected areas falling within the limits shown in Diagram 11.5 can be ignored.

Method 2

11.19This method may be used for buildings or compartments for which method 1 is not appropriate.

11.20The building should not exceed 10m in height. Each side of the building should meet the limits stated in Table 11.1. Any areas falling within the limits shown in Diagram 11.5 can be ignored.

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Sprinkler systems

11.21If a building is fitted throughout with a sprinkler system in accordance with Appendix E, either of the following is permitted.

a.The boundary distance can be halved, to a minimum distance of 1m.

b.The amount of unprotected area can be doubled.

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Introduction

12.1‘Roof covering’ describes one or more layers of material, but not the roof structure as a whole.

12.2Provisions for the fire properties of roofs are given in other parts of this document.

a.Requirement B1 – for roofs that are part of a means of escape.

b.Requirement B2 – for the internal surfaces of rooflights as part of internal linings.

c.Requirement B3 – for roofs that are used as a floor and for roofs passing over a compartment wall.

d.Section 11 – the circumstances in which a roof is subject to the provisions for space separation.

Separation distances

12.3Separation distance is the minimum distance from the roof, or part of the roof, to the relevant boundary (paragraph 11.4). Table 12.1 sets out separation distances by the type of roof covering and the size and use of the building. In addition, roof covering products (and/or materials) defined in Commission Decision 2000/553/ EC of 6 September 2000, implementing Council Directive 89/106 /EEC, can be considered to fulfil all of the requirements for the performance characteristic ‘external fire performance’ without the need for testing, provided that any national provisions on the design and execution of works are fulfilled, and can be used without restriction.

12.4The performance of rooflights is specified in a similar way to the performance of roof coverings. Plastic rooflights may also be used.

Plastic rooflights

12.5Table 12.2 and Diagram 12.1 set the limitations for using plastic rooflights whose lower surface has a minimum class D–s3, d2 rating.

12.6Table 12.3 sets the limitations for using thermoplastic materials with a TP(a) rigid or TP(b) (see also Diagram 12.1) classification. The method of classifying thermoplastic materials is given in Appendix B.

12.7Other than for the purposes of Diagram 5.2, polycarbonate or uPVC rooflights achieving a minimum rating of class C–s3, d2 can be regarded as having a B_ROOF(t4) classification.

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12.8When used in rooflights, unwired glass a minimum of 4mm thick can be regarded as having a B_ROOF(t4) classification.

Thatch and wood shingles

12.9If the performance of thatch or wood shingles cannot be established, they should be regarded as having an E_ROOF(t4) classification in Table 12.1.

a.The rafters are overdrawn with construction having not less than 30 minutes’ fire resistance.

b.The guidance given in Approved Document J is followed.

c.The smoke alarm installation (see Section 1) extends to the roof spaces.

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These sections deal with the following requirement from Part B of Schedule 1 to the Building Regulations 2010.

Intention

Provisions covering access and facilities for the fire service are to safeguard the health and safety of people in and around the building. Their extent depends on the size and use of the building. Most firefighting is carried out within the building. In the Secretary of State’s view, requirement B5 is met by achieving all of the following.

a.External access enabling fire appliances to be used near the building.

b.Access into and within the building for firefighting personnel to both:

i.search for and rescue people

ii.fight fire.

c.Provision for internal fire facilities for firefighters to complete their tasks.

d.Ventilation of heat and smoke from a fire in a basement.

e.A facility to store building information for firefighters to complete their tasks.

If an alternative approach is taken to providing the means of escape, outside the scope of this approved document, additional provisions for firefighting access may be required. Where deviating from the general guidance, it is advisable to seek advice from the fire and rescue service as early as possible (even if there is no statutory duty to consult).

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Provision and design of access routes and hardstandings

13.1For dwellinghouses, access for a pumping appliance should be provided to within 45m of all points inside the dwellinghouse.

Every elevation to which vehicle access is provided should have a suitable door(s), not less than 750mm wide, giving access to the interior of the building.

13.2For flats, either of the following provisions should be made.

a.Provide access for a pumping appliance to within 45m of all points inside each flat of a block, measured along the route of the hose. Every elevation to which vehicle access is provided should have a suitable door(s), not less than 750mm wide, giving access to the interior of the building. Door(s) should be provided such that there is no more than 60m between each door and/or the end of that elevation (e.g. a 150m elevation would need at least two doors).

b.Provide fire mains in accordance with paragraphs 13.5 and 13.6.

13.3Access routes and hardstandings should comply with the guidance in Table 13.1.

13.4Dead-end access routes longer than 20m require turning facilities, as in Diagram 13.1. Turning facilities should comply with the guidance in Table 13.1.

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Blocks of flats fitted with fire mains

13.5For buildings fitted with dry fire mains, both of the following apply.

a.Access should be provided for a pumping appliance to within 18m of each fire main inlet connection point. Inlets should be on the face of the building.

b.The fire main inlet connection point should be visible from the parking position of the appliance, and meet the provisions in Section 8 of BS 9990.

13.6For buildings fitted with wet fire mains, access for a pumping appliance should comply with both of the following.

a.Within 18m, and within sight, of an entrance giving access to the fire main.

b.Within sight of the inlet to replenish the suction tank for the fire main in an emergency.

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Introduction

14.1Fire mains are installed for the fire and rescue service to connect hoses for water. They may be either of the following.

a.The ‘dry’ type, which are both of the following.

i.Normally kept empty.

ii.Supplied through a hose from a fire and rescue service pumping appliance.

b.The ‘wet’ type, which are both of the following.

i.Kept full of water.

ii.Supplied by pumps from tanks in the building.

There should be a facility to replenish a wet system from a pumping appliance in an emergency.

Provision of fire mains

14.2Buildings with firefighting shafts should have fire mains provided in both of the following.

a.The firefighting stairs.

b.Where necessary, in protected stairways.

The criteria for providing firefighting shafts and fire mains are given in Section 15.

14.3Buildings without firefighting shafts should be provided with fire mains where fire service vehicle access is not provided in accordance with paragraph 13.2(a). In these cases, the fire mains should be located within the protected stairway enclosure, with a maximum hose distance of 45m from the fire main outlet to the furthest point inside each flat, measured on a route suitable for laying a hose.

Design and construction of fire mains

14.4The outlets from fire mains should be located within the protected stairway enclosure (see Diagram 15.1).

14.5Guidance on the design and construction of fire mains is given in BS 9990.

14.6Buildings with a storey more than 50m above fire service vehicle access level should be provided with wet fire mains. In all other buildings where fire mains are provided, either wet or dry fire mains are suitable.

14.7Fire service vehicle access to fire mains should be provided as described in paragraphs 13.5 and 13.6.

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14.8A building requires additional fire hydrants if both of the following apply.

a.It has a compartment with an area of more than 280m².

b.It is being erected more than 100m from an existing fire hydrant.

14.9If additional hydrants are required, these should be provided in accordance with the following.

a.For buildings provided with fire mains – within 90m of dry fire main inlets.

b.For buildings not provided with fire mains – hydrants should be both of the following.

i.Within 90m of an entrance to the building.

ii.A maximum of 90m apart.

14.10Each fire hydrant should be clearly indicated by a plate, fixed nearby in a conspicuous position, in accordance with BS 3251.

14.11Guidance on aspects of the provision and siting of private fire hydrants is given in BS 9990.

Alternative supply of water

14.12An alternative source of water should be supplied where any of the following apply.

a.No piped water supply is available.

b.Pressure and flow in the water main are insufficient.

c.An alternative source of supply is proposed.

14.13The alternative source of water supply should be one of the following, subject to consultation with the local fire and rescue service.

a.A charged static water tank with a minimum capacity of 45,000 litres.

b.A spring, river, canal or pond that is capable of fulfilling both of the following conditions.

i.Providing or storing a minimum of 45,000 litres of water at all times.

ii.Providing access, space and a hardstanding for a pumping appliance.

c.Any other water supply that the local fire and rescue service considers appropriate.

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Provision of firefighting shafts

15.1In low rise buildings without deep basements, access for firefighting personnel is typically achieved by providing measures for fire service vehicle access in Section 13 and means of escape.

15.2A building with a storey more than 18m above the fire and rescue service vehicle access level should have one or more firefighting shafts, each containing a firefighting lift (Diagram 15.1). The number and location of firefighting shafts should comply with paragraphs 15.4 to 15.7. Firefighting shafts are not required to serve a basement that is not large or deep enough to need one (see paragraph 15.3 and Diagram 15.2).

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15.3A building with basement storeys should have firefighting shafts in accordance with the following.

a.There is a basement more than 10m below the fire and rescue service vehicle access level. The firefighting shafts should contain firefighting lifts.

b.There are two or more basement storeys, each with a minimum area of 900m². The firefighting shafts do not need to include firefighting lifts.

The building’s height and size determine whether firefighting shafts also serve upper storeys.

15.4Firefighting shafts should serve all storeys through which they pass.

15.5In buildings where a firefighting shaft is required, a minimum of two firefighting shafts should be provided to buildings with a storey that has both of the following.

a.A floor area of 900m² or more.

b.A floor level 18m or more above the fire and rescue service vehicle access level.

15.6Firefighting shafts and protected stairways should be positioned such that every part of each storey more than 18m above the fire and rescue service vehicle access level complies with the maximum distances given in paragraph 15.7. Distances should be measured from the fire main outlet on a route suitable for laying a hose.

15.7In any building, the hose laying distance should meet all of the following conditions.

a.A maximum of 60m from the fire main outlet in a firefighting shaft (see Diagram 15.3).

b.Additionally, where sprinklers have not been provided in accordance with Appendix E, the hose laying distance should be a maximum of 45m from a fire main outlet in a protected stairway (although this does not imply that the protected stairway needs to be designed as a firefighting shaft (see Diagram 15.3)).

Design and construction of firefighting shafts

15.8Firefighting stairs and firefighting lifts should be approached from either of the following.

a.A firefighting lobby.

b.A protected corridor or protected lobby that complies with the following guidance.

i.Means of escape (Section 3).

ii.Compartmentation (Section 7).

Both the stair and lobby of the firefighting shaft should be provided with a means of venting smoke and heat (see clause 27.1 of BS 9999).

Only services associated with the firefighting shaft, such as ventilation systems and lighting for the firefighting shafts, should pass through or be contained within the firefighting shaft.

Doors of a firefighting lift landing should be a maximum of 7.5m from the door to the firefighting stair (Diagram 15.1).

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15.9Firefighting shafts should achieve a minimum fire resistance of REI 120. A minimum of REI 60 is acceptable for either of the following (see Diagram 15.1).

a.Constructions separating the firefighting shaft from the rest of the building.

b.Constructions separating the firefighting stair, firefighting lift shaft and firefighting lobby.

15.10All firefighting shafts should have fire mains with outlet connections and valves at every storey.

15.11A firefighting lift installation includes all of the following.

a.Lift car.

b.Lift well.

c.Lift machinery space.

d.Lift control system.

e.Lift communications system.

The lift shaft should be constructed in accordance with Section 6 of BS 9999.

Firefighting lift installations should conform to BS EN 81-72 and BS EN 81-20.

Rolling shutters in compartment walls

15.12The fire and rescue service should be able to manually open and close rolling shutters without the use of a ladder.

Wayfinding signage for the fire service

15.13To assist the fire service to identify each floor in a block of flats with a top storey more than 11m above ground level (see Diagram D6), floor identification signs and flat indicator signs should be provided.

15.14The floor identification signs should meet all of the following conditions.

a.The signs should be located on every landing of a protected stairway and every protected corridor/lobby (or open access balcony) into which a firefighting lift opens.

b.The text should be in sans serif typeface with a letter height of at least 50mm. The height of the numeral that designates the floor number should be at least 75mm.

c.The signs should be visible from the top step of a firefighting stair and, where possible, from inside a firefighting lift when the lift car doors open.

d.The signs should be mounted between 1.7m and 2m above floor level and, as far as practicable, all the signs should be mounted at the same height.

e.The text should be on a contrasting background, easily legible and readable in low level lighting conditions or when illuminated with a torch.

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15.15The wording used on each floor identification sign should take the form Floor X, with X designating the number of the storey, as intended for reference by residents. The floor number designations should meet all of the following conditions.

a.The floor closest to the mean ground level (see Diagram D4) should be designated as either Floor 0 or Ground Floor.

b.Each floor above the ground floor should be numbered sequentially beginning with Floor 1.

c.A lower ground floor should be designated as either Floor −1 or Lower Ground Floor.

d.Each floor below the ground floor should be numbered sequentially beginning with Floor −1 or Basement 1.

15.16All floor identification signs should be supplemented by flat indicator signs, which provide information relating to the flats accessed on each storey. The flat indicator signs should meet all of the following conditions.

a.The signs should be sited immediately below the floor identification signs, such that the top edge of the sign is no more than 50mm below the bottom edge of the floor identification sign.

b.The wording should take the form Flats X–Y, with the lowest flat number first.

c.The text should be in sans serif typeface with a letter height of at least half that of the floor indicator sign.

d.The wording should be supplemented by arrows when flats are in more than one direction.

e.The text and arrows should be on a contrasting background, easily legible and readable in low level lighting conditions or when illuminated with a torch.

Evacuation alert systems

15.17In blocks of flats (purpose group 1(a)) with a top storey over 18m above ground level (see Diagram D6 in Appendix D) an evacuation alert system should be provided in accordance with BS 8629.

Secure information boxes

15.18A secure information box provides a secure facility to store information about a building for use by the fire service during an incident.

15.19Blocks of flats (purpose group 1(a)) with a top storey more than 11m above ground level (see Diagram D6 in Appendix D) should be provided with a secure information box.

15.20The box should meet all of the following conditions.

a.Sized to accommodate all necessary information.

b.Easily located and identified by firefighters.

c.Secured to resist unauthorised access but readily accessible by firefighters.

d.Protected from the weather.

15.21Best practice guidance can be found in Sections 2 to 4 of the Code of Practice for the Provision of Premises Information Boxes in Residential Buildings published by the Fire Industry Association (FIA).

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Provision of smoke outlets

16.1Heat and smoke from basement fires vented via stairs can inhibit access for firefighting personnel. This may be reduced by providing smoke outlets, or smoke vents, which allow heat and smoke to escape from the basement levels to the open air. They can also be used by the fire and rescue service to let cooler air into the basements (Diagram 16.1).

16.2Each basement space should have one or more smoke outlets.

Where this is not practicable (for example, the plan area is deep and the amount of external wall is restricted by adjoining buildings), the perimeter basement spaces may be vented, with other spaces vented indirectly by opening connecting doors. This does not apply for places of special fire hazard (see paragraph 16.7).

If a basement is compartmented, each compartment should have one or more smoke outlets, rather than indirect venting.

A basement storey or compartment containing rooms with doors or windows does not need smoke outlets.

16.3Smoke outlets connecting directly to the open air should be provided from every basement storey, except for any basement storey that has both of the following.

a.A maximum floor area of 200m².

b.A floor a maximum of 3m below the adjacent ground level.

16.4Strong rooms do not need to be provided with smoke outlets.

Natural smoke outlets

16.5Smoke outlets should be both of the following.

a.Sited at high level in either the ceiling or wall of the space they serve.

b.Evenly distributed around the perimeter, to discharge to the open air.

16.6The combined clear cross-sectional area of all smoke outlets should be a minimum of 1/40 of the area of the floor of the storey they serve.

16.7Separate outlets should be provided from places of special fire hazard.

16.8If the smoke outlet terminates at a point that is not readily accessible, it should be kept unobstructed and covered only with a class A1 grille or louvre.

16.9If the smoke outlet terminates in a readily accessible position, it may be covered by a panel, stallboard or pavement light that can be broken out or opened. The position of covered smoke outlets should be suitably indicated.

16.10Outlets should not be placed where they prevent the use of escape routes from the building.

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16.11If basement storeys are fitted with a sprinkler system in accordance with Appendix E, a mechanical smoke extraction system may be provided as an alternative to natural venting. Sprinklers do not need to be installed on the other storeys unless needed for other reasons.

Car parks are not normally expected to be fitted with sprinklers (see Section 11 of Approved Document B Volume 2).

16.12The air extraction system should comply with all of the following.

a.It should give at least 10 air changes per hour.

b.It should be capable of handling gas temperatures of 300°C for not less than one hour.

c.It should do either of the following.

i.Be activated automatically if the sprinkler system activates.

ii.Be activated by an automatic fire detection system that conforms to BS 5839-1 (minimum L3 standard).

Further information on equipment for removing hot smoke is given in BS EN 12101-3.

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16.13Outlet ducts or shafts, including any bulkheads over them (see Diagram 16.1), should be enclosed in construction of class A1 rating and fire resistance at least equal to that of the element through which they pass.

16.14Natural smoke outlet shafts should be separated from each other using construction of class A1 rating and fire resistance at least equal to that of the storeys they serve, where the shafts are either of the following.

a.From different compartments of the same basement storey.

b.From different basement storeys.

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This section deals with the following regulation of the Building Regulations 2010.

Intention

The aim of this regulation is to ensure that the person responsible for the building has sufficient information relating to fire safety to enable them to manage the building effectively. The aim of regulation 38 will be achieved when the person responsible for the building has all the information to enable them to do all of the following.

a.Understand and implement the fire safety strategy of the building.

b.Maintain any fire safety system provided in the building.

c.Carry out an effective fire risk assessment of the building.

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17.1For building work involving the erection or extension of a relevant building (i.e. a building to which the Regulatory Reform (Fire Safety) Order 2005 applies, or will apply), or the relevant change of use of a building, fire safety information should be given to the responsible person at one of the following times.

a.When the project is complete.

b.When the building or extension is first occupied.

17.2This section is a guide to the information that should be provided. Guidance is in terms of essential information and additional information for complex buildings; however, the level of detail required should be considered on a case-by-case basis.

Essential information

17.3Basic information on the location of fire protection measures may be sufficient. An as-built plan of the building should be provided showing all of the following.

a.Escape routes – this should include exit capacity (i.e. the maximum allowable number of people for each storey and for the building).

b.Location of fire-separating elements (including cavity barriers in walk-in spaces).

c.Fire doorsets, fire doorsets fitted with a self-closing device and other doors equipped with relevant hardware.

d.Locations of fire and/or smoke detector heads, alarm call points, detection/alarm control boxes, alarm sounders, fire safety signage, emergency lighting, fire extinguishers, dry or wet fire mains and other firefighting equipment, and hydrants outside the building.

e.Any sprinkler systems, including isolating valves and control equipment.

f.Any smoke control systems, or ventilation systems with a smoke control function, including mode of operation and control systems.

g.Any high risk areas (e.g. heating machinery).

17.4Details should be provided of all of the following.

a.Specifications of fire safety equipment provided, including routine maintenance schedules.

b.Any assumptions regarding the management of the building in the design of the fire safety arrangements.

c.Any provision enabling the evacuation of disabled people, which can be used when designing personal emergency evacuation plans.

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17.5A detailed record should be provided of both of the following.

a.The fire safety strategy.

b.Procedures for operating and maintaining any fire protection measures. This should include an outline cause and effect matrix/strategy for the building.

Further guidance is available in clause 9 and Annex H of BS 9999.

17.6The records should include details of all of the following.

a.The fire safety strategy, including all assumptions in the design of the fire safety systems (such as fire load). Any risk assessments or risk analysis.

b.All assumptions in the design of the fire safety arrangements for the management of the building.

c.All of the following.

i.Escape routes (including occupant load and capacity of escape routes).

ii.Any provision to enable the evacuation of disabled people.

iii.Escape strategy (e.g. simultaneous or phased).

iv.Muster points.

d.All passive fire safety measures, including all of the following.

i.Compartmentation (i.e. location of fire-separating elements).

ii.Cavity barriers.

iii.Fire doorsets, including fire doorsets fitted with a self-closing device and other doors equipped with relevant hardware (e.g. electronic security locks).

iv.Duct dampers.

v.Fire shutters.

e.All of the following.

i.Fire detector heads.

ii.Smoke detector heads.

iii.Alarm call points.

iv.Detection/alarm control boxes.

v.Alarm sounders.

vi.Emergency communications systems.

vii.CCTV.

viii.Fire safety signage.

ix.Emergency lighting.

x.Fire extinguishers.

xi.Dry or wet fire mains and other firefighting equipment.

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xii.Other interior facilities for the fire and rescue service.

xiii.Emergency control rooms.

xiv.Location of hydrants outside the building.

xv.Other exterior facilities for the fire and rescue service.

f.All active fire safety measures, including both of the following.

i.Sprinkler system(s) design, including isolating valves and control equipment.

ii.Smoke control system(s) (or heating, ventilation and air conditioning system with a smoke control function) design, including mode of operation and control systems.

g.Any high risk areas (e.g. heating machinery) and particular hazards.

h.Plans of the building as built, showing the locations of the above.

i.Both of the following.

i.Specifications of any fire safety equipment provided, including all of the following.

•Operational details.

•Operators’ manuals.

•Software.

•System zoning.

•Routine inspection, testing and maintenance schedules.

ii.Records of any acceptance or commissioning tests.

j.Any other details appropriate for the specific building.

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Access room A room that the only escape route from an inner room passes through.

Alternative escape routes Escape routes that are sufficiently separated by direction and space or by fire resisting construction to ensure that one is still available if the other is affected by fire.

Alternative exit One of two or more exits, each of which is separate from the other.

Appliance ventilation duct A duct to deliver combustion air to a gas appliance.

Atrium (plural atria) A continuous space that passes through one or more structural floors within a building, not necessarily vertically.

Automatic release mechanism A device that normally holds a door open, but closes it automatically if any one of the following occurs.

•Smoke is detected by an automatic device of a suitable nature and quality in a suitable location.

•A hand-operated switch, fitted in a suitable position, is operated.

•The electricity supply to the device, apparatus or switch fails.

•The fire alarm system, if any, is operated.

Basement storey A storey with a floor that, at some point, is more than 1200mm below the highest level of ground beside the outside walls. (However, see Appendix B, paragraph B26c, for situations where the storey is considered to be a basement only because of a sloping site.)

Boundary The boundary of the land that belongs to a building, or, where the land abuts a road, railway, canal or river, the centre line of that road, railway, canal or river.

Building Any permanent or temporary building but not any other kind of structure or erection. A reference to a building includes a reference to part of a building.

Building control body A term that includes both local authority building control and approved inspectors.

Cavity A space enclosed by elements of a building (including a suspended ceiling) or contained within an element, but that is not a room, cupboard, circulation space, protected shaft, or space within a flue, chute, duct, pipe or conduit.

Cavity barrier A construction within a cavity, other than a smoke curtain, to perform either of the following functions.

•Close a cavity to stop smoke or flame entering.