Standard Assessment Procedure (SAP)
Standard Assessment Procedure (SAP) calculations are required to prove Building Regulations Part L compliance for all new build properties, all conversions and extensions where the glazed area is over 25% of the floor area. The first part of the SAP calculations involves the assessor working out a Target Emission Rating (TER) for the dwelling. The next step is calculation of the Dwelling Emission Rate (DER). If this is equal to or less than the TER then the SAP rating shows a pass, the SAP calculations are complete and the building is certified as compliant with Part L of the Building Regulations.
The SAP calculations are used to determine how a property scores on Energy and CO2 emissions category under the Code for Sustainable Homes.
More information on Code for Sustainable Homes
Energy Performance Certificates
From October 2008 all buildings, whenever sold, built or rented, need an Energy Performance Certificate (EPC).
The certificate provides energy efficiency A-G ratings and recommendations for improvement. The ratings - similar to those found on products such as fridges - are standard so the energy efficiency of one building can easily be compared with another building of a similar type.