INTRODUCTION

In the early 1980s, a method for calculating the energy use of dwellings was needed which was better than simple procedures such as design heat loss calculations, but easier to use than detailed simulation models. The aim in designing the Building Research Establishment Domestic Energy Model (BREDEM) was to develop a procedure which gave robust estimates of energy use and was simple to use. BREDEM was designed around an analytical approach of balancing heat losses and heat gains, but it also included some empirical elements, based on experience of how energy is actually used in dwellings. This approach proved very successful and has remained central to BREDEM in all its various versions.

BREDEM has been updated regularly, with BREDEM-9 published as SAP for energy rating of dwellings by BRE in 1993 on behalf of the Department of Energy – now DECC. It was amended in 1994 and conventions to be used within the procedure were published in 1996, with a further amendment in 1997. A consolidated edition was published in 1998 as SAP 1998. The SAP 2001 edition introduced a carbon index as an additional output, which could be used to demonstrate compliance with the Building Regulations.