Correspondence

Building regulations: updated notices of approval for calculation methodologies: circular letter

Published 17 March 2025

Applies to England

© Crown copyright 2025

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This publication is available at https://www.gov.uk/government/publications/building-regulations-updated-notices-of-approval-for-calculation-methodologies-circular-letter/building-regulations-updated-notices-of-approval-for-calculation-methodologies-circular-letter

Updated Notice of approval of the methodologies of calculation of the energy performance of new buildings to demonstrate compliance with the Building Regulations 2010 in England

Updated Notice of approval of the methodologies for expressing the energy performance of buildings in England and Wales

Dear Sir or Madam,

I am writing to inform you that a minor update has been made to the specification of SAP 10.2, the approved methodology for calculating and expressing the energy performance of new domestic buildings in England. The methodology has been amended to allow a limited tolerance (+/-3%) in cases affected by a software error.  The tolerance can only be applied where a building was assessed as compliant by faulty software and, when assessed correctly, only misses the relevant target rate by 3% or less.

As a result, we have issued updated notices of approval for the following:

  • The calculation methodologies of the energy performance of new buildings to demonstrate compliance with the Building Regulations 2010. This notice applies to England.
  • The methodologies for expressing the energy performance of buildings in England and Wales. This notice applies to England and Wales however methodology that has been updated only applies in England.

Scope of this circular letter

The guidance in this circular letter applies to bodies carrying out building control functions in England .

The updated notices of approval are available on the GOV.UK website at:

The approved methodologies should be used from 17 March 2025.

Enquiries

Enquiries on this circular letter should be addressed to buildingassurance@communities.gov.uk.

Yours faithfully

John Palmer

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