The document outlines a comprehensive approach for implementing energy efficiency measures in built heritage, emphasizing the balance between enhancing energy performance and preserving cultural values. It introduces specific methodologies for the energy renovation of heritage buildings, detailing preparatory steps, assessment of current conditions, and the selection of appropriate energy efficiency measures that do not compromise the building’s historical integrity. The strategy includes conducting preliminary energy analyses, integrating renewable energy sources when feasible, and applying non-invasive, reversible interventions to ensure the long-term preservation of the building’s authentic characteristics while improving its energy efficiency. This approach underscores the importance of a multidisciplinary collaboration among conservationists, engineers, and architects to achieve a sustainable and respectful renovation that aligns with the conservation principles and the building’s cultural significance.