Standard Assessment Procedure (SAP 10)

This site hosts documents and information relating to version 10 of the Standard Assessment Procedure (SAP 10).

Please note that versions 10.0 and 10.1 of SAP must not be used for any official purpose. SAP 10.2 will be used for official purposes in due course, but until further notice  SAP 2012 must continue to be used for Building Regulation compliance and for producing Energy Performance Certificates, in conjunction with the 2006 edition of BR443 (for calculating U-values). 

SAP 10.1 was published in October 2019 to coincide with the publication of the UK Government’s Future Homes Standard consultation and the Welsh Government’s Building Regulations Part L and F consultation, which discuss proposed changes to Building Regulations Approved Documents, making reference to SAP 10. The SAP 10.1 specification document can still be downloaded from the link below.

The software implementation of SAP 10.1 used for the UK Government’s consultation is available here.

The software implementation of SAP 10.1 used for the Welsh Government’s consultation is available here.

SAP 10.2 (20-08-2021) has subsequently been published. This is a near-complete edition of the version that will come into use for live assessments (expected in mid-2022). However, at the time of publication, there are two unresolved areas. One is whether a multiplier should be applied to the Target Fabric Energy Efficiency, which is subject to the outcome of the Future Buildings Standard consultation and could require a minor change to the SAP 10.2 specification. The other is the treatment of heat networks, which is under review following a separate recent consultation by BEIS, so some sections relating to this are indicated as under review. Please refer to the Government’s forthcoming response to this consultation, which will set out how heat networks will be treated. An update to Appendix C of SAP 10.2 will be made following publication of the consultation response.


SAP 10.2 specification (20/08/2021)

SAP 10.1 specification (08/11/2019) [superseded by version 10.2]

Briefing note on primary energy factors used in SAP 10.1 (01/10/2019)

SAP 10.0 specification (24/07/2018) [superseded by version 10.1]

SAP 10 Technical Paper S10TP-15: CO2 and Primary Energy Factors for SAP Version 1.1 (25/11/2020)