Volume 1, Number  1, Jan-July 2000

The SAP Energy Rating: An Effective Tool to Use Energy More Efficiently in Dwellings

Saleem  Raza Samo, Abdul Sami Memon, and Abdul Ghani Memon

Abstract:

The SAP energy ratings - based on extensive research from the UK Government's Building Research Establishment, provide a simple indicator of the efficiency of energy use for space and domestic water heating. The energy efficiency of an individual dwelling can be described by giving it an 'Energy Rating'. Generally, an energy rating is a measure of the annual unit cost of heating the dwelling to a standard regime, assuming a certain heating pattern and specific room temperature. The rating obtained from following the SAP procedure depends upon a range of factors that contribute to energy efficiency. In this paper the impact of the thermal insulation, and efficiency & control of the heating system on the SAP energy rating have been investigated. This study has also pointed out some areas where the SAP energy rating could be improved, for example the fabric thermal insulation could increase the SAP energy from 33 to 80. Moreover the heating systems and their controlling devices have a significant effect on the SAP rating. The SAP energy rating of a semi-detached house having the floor standing pre-1979 gas boiler withno heating controls was 31 points. If the same house could be upgraded with a  condensing combi gas boiler controlled by the zone control system then its SAP energy rating could be increased from 31 to 54 (an increase of 23 points).