SAP stands for the Government’s Standard Assessment Procedure (SAP) for assessing the energy performance of dwellings. The indicators of the energy performance are energy consumption per unit floor area, an energy cost rating (the SAP rating), an Environmental Impact rating (based on CO2 emissions) and a Dwelling CO2 Emission Rate (DER).

The SAP rating is based on the energy costs associated with space heating, water heating, ventilation and lighting, less cost savings from energy generation technologies. It is adjusted for floor area so that it is essentially independent of dwelling size for a given built form. The SAP rating is expressed on a scale of 1 to 100, the higher the number the lower the running costs.

An EPC (Energy Performance Certificate) provides a rating for the energy efficiency of a building. The ratings are set against standard criteria to enable one building to be compared with another of a similar type. EPCs are similar to the certificates now provided with domestic appliances such as refrigerators and washing machines.

They give information on the energy performance as well as the environmental impact through carbon emissions. This information is rated on a scale of A to G, where A is the best and should have the lowest fuel bill. The average UK property is in bands D to E.

SBEM stands for Simplified Building Energy Model. SBEM is a computer program that provides an analysis of a commercial building's energy consumption. SBEM estimates the monthly energy use and carbon emissions of a building. iSBEM is the Interface tool for the Simplified Building Energy Model developed for CLG in compliance to the EPBD.