What is SAP?

Standard Assessment Procedure (SAP) is a method for calculating the CO2 emissions of dwellings. SAP calculation is required for all new domestic buildings and some extensions and conversions to demonstrate compliance with the Building Regulations Part L1.

Using an approved SAP software, the CO2 emission of a domestic building can be calculated based on the building specifications. This CO2 emission is called the Dwelling Emission Rate (DER). For a building to be compliant with the regulations, the DER must not be greater than the TER (Target Emission Rate).

There is also a requirement for the dwelling fabric efficiency to meet building regulations standards which means that Dwelling Fabric Energy Efficiency (DFEE) should be lower than that Target Fabric Energy Efficiency (TFEE).

SAP calculation is done in two stages – at the design stage and the built stage. The SAP method is also used to calculate the EPCs for the dwelling .