Demonstrating impact and de-risking: Retrofit industry perspectives on Building Performance Evaluation in the United Kingdom

Significant investment is being made to retrofit buildings to meet decarbonisation targets and alleviate fuel poverty globally. The application of Building Performance Evaluation (BPE) in retrofitted dwellings in the UK is often limited to simplistic energy models in the form of Energy Performance Certificates. However, recent technological advances have introduced a range of alternative BPE methods that can gather data from buildings and residents to supplement or inform Energy Performance Certificates. In this study, perspectives from 54 retrofit professionals in the UK were gained through workshops and semi-structured interviews. The data were analysed thematically to understand what methods of BPE were being used, as well as the respective barriers and drivers of their adoption. Participants were familiar with the limitations of Energy Performance Certificates and were frequently using complementary BPE methods to fulfil broader purposes across four categories: support decision making; de-risk retrofits; demonstrate impact; and provide learning and improvement. Specific barriers were identified that limited the utilisation of BPE methods including practical aspects as well as incompatibility with funding schemes and current industry norms. These findings inform a conceptual model of the BPE landscape in retrofit. The model highlights the causes and implications of an underperforming market whilst identifying policy voids that, if addressed, could drive greater BPE uptake and improve project outcomes across the UK.