Balancing Efficiency and Conservation: A Review of Energy Retrofitting Approaches for Historical Buildings in the Mediterranean Context

Improving the energy performance of historical buildings is a key challenge for decarbonising the European built environment. In the Mediterranean context, retrofit design is especially complex because interventions must reduce heating and cooling demand while preserving architectural and cultural values. Although research on this topic has grown, available evidence remains fragmented, with studies often focused on individual case studies and isolated retrofit packages. This review systematises the literature on energy retrofit interventions for historical buildings in the European Mediterranean region by linking retrofit measures, energy outcomes and conservation constraints. A PRISMA-based workflow was used to select articles published between 2010 and 2025 from Scopus and Web of Science. The results show a predominance of envelope-based measures, often combined with HVAC improvements. Passive–active packages achieve the highest reported reductions, up to 87% for heating and 75% for cooling. Conservation constraints do not necessarily prevent energy improvement, but they influence the admissibility, location and invasiveness of retrofit measures. Overall, the evidence indicates that energy retrofit of Mediterranean historical buildings should focus on heating reduction, cooling resilience and hygrothermal safety. The review provides a framework for identifying compatible retrofit pathways according to the architectural and material transformability of historical buildings.