Compatibility of Energy Efficiency with the Protection of Historic Buildings: A Systematic Literature Review

Achieving improvement of energy performance in listed buildings remains a complex challenge due to the need to combine innovative solutions with preservation of the characteristics that define the historical and architectural value of these buildings. The aim of this study is to better understand the state of the art regarding the compatibility of energy efficiency measures with the protection of listed buildings. A systematic review was performed that included peer-reviewed publications in English and Italian from Scopus, Web of Science, and Google Scholar (last search: November 2025). Sixty-nine studies were included and organized into methodological, applicative, review and theoretical-reflective studies. Results show a European predominance, particularly Italian, and identify four recurring themes: balancing efficiency with conservation, decision-making processes, evaluation criteria, and technological strategies. Current research is focusing on developing objective evaluation methods, moving toward multi-criteria methodologies that quantify aesthetic, technical, and environmental compatibility. While there is a preference for minimally invasive and reversible technological solutions, the review reveals a lack of shared protocols and limited generalizability of results. The study concludes that a strategic shift is required: moving from isolated experiments to integrated urban policies. Furthermore, it highlights a need for increased technical training to bridge the gap between research and practical application. Future research should focus on validating evaluation criteria using real cases and developing regional policy tools to support decision-making. This review was not registered.