The expanding house : extensions to domestic buildings and their impact on energy consumption

The energy impact of extensions, defined as the percentage increase in total household energy consumption caused by an extension, has been investigated and quantified. This has been achieved through a two-step process. Firstly, a set of typical extension sizes and prevalence was defined through a survey using publicly available aerial imagery and GIS mapping software. Secondly the energy impact of these extensions was predicted through the application of a reduced data Standard Assessment Procedure. A catalogue of extension types has been created and statistically significant relationships between extension prevalence and tenure, household income and building archetype have been proven. The energy impact of extensions has been estimated to be 16% on average across all building and extension types; which would account for 3.8% of England’s domestic energy demand if the results of this study were scaled nationally.