Standard Assessment Procedure (SAP)

The Standard Assessment Procedure (SAP) is the Department of Energy and Climate Change’s (DECC) methodology for assessing and comparing the energy and environmental performance of dwellings.

SAP works by assessing how much energy a dwelling will consume and how much carbon dioxide (CO2 ) will be emitted in delivering a defined level of comfort and service provision, based on standardized occupancy conditions. This enables a like for like comparison of dwelling performance.


SAP quantifies a dwelling’s performance in terms of: energy use per unit floor area, a fuel cost based energy efficiency rating (the SAP rating) and emissions of CO2. These indicators of performance are based on estimates of annual energy consumption for the provision of space heating, domestic hot water, lighting and ventilation. Other SAP outputs include estimate of appliance energy use, the potential for overheating in summer and the resultant cooling load.

Case Study


With ever tightening building regulations it is becoming more and more complicated to obtain even a ‘pass’ for many new dwellings.

We are now able to use a methodology which provides another route to Part L compliance – by calculating the Dwelling Emission Rate (DER) in IES DSM software and then using SAP to calculate the Target Emission Rate (TER) and EPC.

Our Accreditation Body, CIBSE, agree this is perfectly acceptable with the only caveat being assent from the Building Control officer.

Whilst the calculations are more complicated and time consuming, the cost and time savings to house developers can be substantial. The video Case Study to the left explains how the methodology using IES DSM software demonstrates compliance with Building Regulations Part L.