Key performance indicators. Their use in the energy efficiency retrofit for historic buildings

Energy efficiency in the built environment is gaining ground due to policies to mitigate climate change impact. This contribution focuses on investigating the role of Key Performance Indicators (KPIs) that can be useful for the energy retrofit of historic buildings. The KPIs were hinged upon PESTEL domains (Political, Economic, Social, Technological, Environmental, and Legislative) in order to define objective and measurable criteria that allow for a comprehensive evaluation of an energy retrofit performance. A literature review carried out through the PRISMA flow chart allowed to select 59 papers, subsequently analyzed to investigate the occurrences of the selected KPIs. The findings showed that the political domain is the less considered, differently from the legislative one, whose KPI highlighted the importance of being compliant with regulations. The domains representing economic, social, technological, and environmental KPIs are mostly present together in the scientific literature, underlining the importance of a holistic and multidisciplinary approach. Future research should be oriented towards delineation of best practices to meet sustainability and conservation needs, and to better integrate current policies and international requirements.