Reconciling Heritage Buildings' Preservation with Energy Transition Goals: Insights from an Italian Case Study

The construction industry in Europe significantly contributes to energy consumption and carbon dioxide emissions, and this has prompted the European Union to issue directives for renovating and decarbonizing the existing building stock to meet 2050's energy and environmental targets. However, achieving nearly zero-energy building (nZEB) standards in historic buildings is a complex challenge, as heritage values cannot be compromised for the sake of energy improvements. Our research advocates for a "whole building approach", integrating various disciplines to achieve low-energy retrofitting while preserving historical material authenticity. The proposed methodology, inspired by the EN16883:2017 standard, involves a comprehensive building survey and assessment, the definition of conservation-compatible design solutions, and a performance analysis of these selected measures in relation to nZEB standards. This method was then applied to an ongoing project on a small, listed building in Genoa, demonstrating the feasibility of achieving conservation and high energy savings and, in these specific circumstances, the possibility of approaching nZEB parameters. This best practice example highlights the importance of adopting a cross-disciplinary, structured method to balance different values and needs in retrofitting projects, and it shows how creative and innovative solutions can break down the typical barriers encountered when implementing retrofitting solutions for built heritage.