Edinburgh Napier University

  The study reports on the differences between the actual heat consumption profiles of twelve dwellings monitored for four years and their predicted heat demand profiles as calculated by the UK Government’s Standard Assessment Procedure (SAP). This monitoring methodology analysed the selected homes over 4 years of occupation leading to a longitudinal study. Using descriptive statistical metrics this paper considers different groupings and normalisation methods to understand differences in heat demand. It uses this methodology to compare predicted over delivered energy over longer occupation periods. The results demonstrate that the compliance SAP model, incorrectly estimates heat demand by up to one and a half times that recorded in these dwellings. It also concludes that analysing energy consumption over time should exclude early occupation years as they suffer from occupant adjustment periods. Furthermore, by applying a heat energy factor, none of the dwellings achieve equal or better consumption levels than SAP, however flats and the low consuming group dwellings achieve closest to the predicted.