Of the 28 million residential properties within the UK, 19 million are poorly insulated and hence energy inefficient. It is a challenge to improve the energy efficiency of these buildings. Retrofitting measures reduce energy consumption in homes and improve occupant comfort, make homes healthier and reduce fuel bills. Local authorities across the UK are undertaking thousands of retrofits each year; however, the measurement of the impact of these retrofit activities is haphazard. The retrofit assessments taking place are fragmented, complex to implement, expensive, inconsistent in their approach, and therefore not a comparable, standardised assessment of the retrofit work done. The lessons learnt and best practices are not being shared, and there remains uncertainty around the benefits that are being delivered to communities. This research aims to understand how to improve retrofit assessments.
To address this problem, the UK Green Building Council (UKGBC) developed a toolkit called the Build Upon 2 Framework. It was meant to evaluate retrofit projects and standardise how to quantify social, environmental and economic benefits of projects. In addition to collecting technical data from energy models such as the Energy Performance Certificate (EPC) and economic data from contractors, the toolkit uses the occupant questionnaire as a central tool to understand the impact of the retrofit from the occupant’s perspective.
However, the questionnaire is untested; this research aims to explore its effectiveness and make recommendations on its development and implementation. It analyses the results from a case study retrofit project in the North of England where it was deployed by a local council.
This research may lead to the revision of the UKGBC toolkit, which may be adopted by other organisations wishing to undertake standardised evaluations of their retrofit projects and may also be used as a reference toolkit by organisations funding retrofit to ensure their projects include consistent retrofit evaluations.