Calculation of buildings' energy performance and new approved documents (WG 013/2014)

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Circular

Issued by:

Francois Samuel: Head of Building Regulations

Summary:

In accordance with the requirements of the Building Regulations 2010 this circular informs of the updated calculation methodologies for the energy performance of buildings in Wales, and publication of Approved Documents L1A (2014), L1B (2014), L2A (2014) and L2B (2014) for Wales.

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NOTICE OF APPROVAL FOR CALCULATION METHODOLOGIES AND APPROVED DOCUMENTS L1A, L1B, L2A and L2B.

1.I am directed by Welsh Ministers to inform you of the issue of a new notice of approval for the updated calculation methodologies for CO 2 emissions, fabric performance values for new dwellings, primary energy consumption rates for new buildings and energy performance certificates for new buildings.

2.I am also directed by Welsh Ministers to draw your attention to the publication of the final versions of the Approved Documents L1A, L1B, L2A, and L2B.

Scope of this Circular Letter

3.This Circular letter applies to buildings and building work in Wales. It does not apply to excepted energy buildings1 in Wales.

1Excepted Energy Buildings are defined in the schedule to the Welsh Ministers (Transfer of Functions) (No.2) Order 2009 (S.I. 2009/3019).

Notice of approval for the methodologies of calculation of the energy performance of buildings

4.Regulations 25, 25C, 26, 26A, 26B, 27, 27A, 27B and 29 of the Building Regulations 2010 require that the calculation of energy performance of new buildings shall be carried out using a methodology approved by the Welsh Ministers under regulation 24 of those Regulations.

5.To coincide with the coming into effect of amendments to the energy efficiency requirements of the Building Regulations a notice of approval for updated approved methodologies is attached at Annex A.

6.The coming into effect date for the approved methodologies is 31 July 2014. The notice sets out what buildings to which the updated methodologies will apply and where previous versions of the methodologies may continue to be used.

Approved Documents L1A, L1B, L2A, and L2B

7.The Approved Documents L1A, L1B, L2A, and L2B have been approved by the European Commission in accordance with the Technical Standards and Regulations Directive 98/34/EC. The Approved Documents will come into force on the 31 July 2014, and can be viewed on the following web link: www.wales.gov.uk/topics/planning/buildingregs/publications/part-l-energy

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Enquiries

Any enquiries on this Circular Letter should be addressed to:

Colin Blick, Building Regulations, Welsh Government, Rhydycar, Merthyr Tydfil,

CF48 1UZ.

Telephone: 03000 628144

E mail Colin.Blick@wales.gsi.gov.uk.

Yours faithfully

Francois Samuel

Head of Building Regulations

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Annex A

Notice of Approval of the methodologies of calculation of the energy performance of buildings to demonstrate compliance with the Building Regulations 2010 in Wales.

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Introduction This notice of approval sets out the national approved calculation methodologies (NCM) for calculating the energy performance of certain buildings in Wales in accordance with regulation 24 and for the purposes of regulations 25, 25C and 29 of the Building Regulations 2010 (SI 201 0/2214).

This document does not apply to national calculation methodologies in England, Northern Ireland and Scotland, which are subject to separate regulatory requirements.

The notice of approval for calculating the energy performance of buildings as required by the Energy Performance of Buildings (England and Wales) Regulations 2012 is issued as a separate document by the Department for Communities and Local Government.

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TAKE NOTICE that the Welsh Ministers, under regulation 24 of the Building Regulations 2010, hereby approve the methodologies listed below for the calculation of the energy performance of buildings for the purposes of regulations 25, 25C, and 29 of the Building Regulations 2010. This approval applies to building work carried out in Wales except for excepted energy buildings¹ Crown buildings, or building work by Crown authorities in Wales².

This approval takes effect on 31 July 2014 and continues in effect until withdrawn by Welsh Ministers or superseded.

This approval does not apply in respect of:

(a)building work started on site before 31 July 2014; or

(b)where a notification of building work under regulation 12(2) of the Building

Regulations 2010, or sections 47(1 ), 50, 51A(2) or 54 of the Building Act 1984 has been given before 31 July 2014 provided that the building work is commenced on site before 31 July 2015.

In both these cases earlier versions of the methodologies may continue to be used.

The approved methodologies are:

a.the UK Government's Standard Assessment Procedure (SAP) for the

Energy Rating of Dwellings, 2012 edition; and

b.the UK Government's Simplified Building Energy Model (SBEM), versions

5.2.

Signed

using and Regeneration

¹ As defined in the Schedule to the Welsh Ministers (Transfer of Functions) (No.2) Order 2009 (S.L 2009/3019)

² For these categories see regulation 34 of the Building Regulations 2010

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This notice of approval sets out the ways of expressing the energy performance of buildings, as calculated in accordance with the methodology approved by Welsh Ministers under regulation 24, for the purposes of regulation 25 and 25C (Minimum energy performance requirements for new buildings), and regulation 29 (Energy performance certificates) of the Buildings Regulations 2010.

Software packages and interfaces

To use the approved methodologies it is also necessary to use only the approved software packages and interfaces relating to them. The currently approved software packages and interfaces are available at: www.wales.qov.uk/topics/planninq/buildinqregs/publications/part-l-enerqy

Please note that from time to time the list at this link is revised to include new software applications or new versions of existing ones as they are approved by Welsh Ministers.

Calculating the energy performance of new dwellings .

For the purposes of compliance with regulations 25, 25C(b), 26, 26B, 27 and 27B of the Buildings Regulations 2010, the target C02 emission rate, target fabric performance value, calculated C02 emission rate for the dwelling as designed and constructed and calculated fabric performance value for the dwelling as designed and constructed shall be calculated using SAP 2012. The asset rating of the dwelling for the purposes of providing an energy performance certificate under regulation 29 of the Building Regulations shall also be calculated using SAP 2012.

Calculating the energy performance of new buildings other than dwellings

For the purposes of regulations 25, 25C(a), 26, 26A, 27 and 27A of the Building Regulations the target C02 emission rate, target primary energy consumption rate, calculated C02 emission rate for a building other then a dwelling as designed and constructed and calculated target primary consumption rate for a building other than a dwelling as designed and constructed shall be calculated using SBEM version 5.2 or an approved DSM. The asset rating of a building other than a dwelling for the purposes of providing an energy performance certificate under regulation 29 of the Building Regulations 201 0 shall be calculated using SBEM version 5.2 or an approved DSM.

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Applications may be made to Welsh Ministers for approval of software packages to form part of the methodology for the calculation of the energy performance of buildings, such as:

a.software applications of SAP;

b.software interfaces with SBEM;

c.Dynamic Simulation Models (DSMs).

To be approved, the software tool must be validated against a set of published criteria to ensure it operates in a manner and to a standard consistent with the NCM before it can be approved by Welsh Ministers. The criteria for approval and the procedures for applying for approval may be obtained from:

Building Regulations Welsh Government Rhydycar Merthyr Tydfil CF48 1UZ. Email: enguiries.brconstruction@wales.gsi.gov.uk