The Standard Assessment Procedure (SAP) is adopted by Government as the UK methodology for calculating the energy performance of dwellings.
The calculation is based on the energy balance taking into account a range of factors that contribute to energy efficiency:
- Materials used for construction of the dwelling
- Thermal insulation of the building fabric
- Air leakage ventilation characteristics of the dwelling, and ventilation equipment
- Efficiency and control of the heating system(s)
- Solar gains through openings of the dwelling
- The fuel used to provide space and water heating, ventilation and lighting
- Energy for space cooling, if applicable
- Renewable energy technologies
The calculation is independent of factors related to the individual characteristics of the household occupying the dwelling when the rating is calculated, for example:
- Household size and composition.
- Ownership and efficiency of particular domestic electrical appliances.
- Individual heating patterns and temperatures.