The Standard Assessment Procedure (SAP) is a standardised calculation procedure that models the energy and carbon performance of individual UK homes. It is the methodology that is used by the UK Government to assess and compare the performance of homes.
SAP calculations are used to determine whether new homes comply with the energy efficiency sections of Building Regulations, and to generate Energy Performance Certificates (EPC) for all homes.
The process does not attempt to predict the real-world energy demand, energy cost or carbon emissions of homes, instead testing the homes under a standard set of circumstances (weather, number of occupants, etc.). This standardisation allows results from one home to another to be directly compared. This is useful to Government as it provides a framework within which they can say that one home is more or less efficient than another.
The SAP methodology is periodically updated, with the most recent update having occurred in July 2022. This replaced the previous version which had been used since 2014.