SAP 2005
SAP is the Government's Standard Assessment Procedure for Energy Rating of Dwellings. SAP 2005 is adopted by government as part of the UK national methodology for calculation of the energy performance of buildings. It is used to demonstrate compliance with building regulations for dwellings - Part L (England and Wales), Section 6 (Scotland) and Part F (Northern Ireland) - and to provide energy ratings for dwellings.

When Approved Document L1a came into effect in April 2006, not only was the thermal requirements of the building regulations for England and Wales improved, but the whole method of compliance was radically changed. This is largely as a result of implementing the European Energy Performance of Buildings Directive (EPBD) A key requirement of the EPBD is that an overall energy performance target must be set for each building.

The 2005 version of the Standard Assessment Procedure is the only way of demonstrating the compliance with the new requirements.

SAP 2005 calculates the proposed dwellings energy performance in terms in CO2 emissions per m2 of total floor area per year for heating, hot water, ventilation and lighting. The SAP rating is expressed on a scale of 1 to 100, the higher the number the lower the running costs.

PEA and EPC show the dwellings energy performance in an A - G rating similar to those found on new white goods. The nearer to A the better