Climate Mitigation and Adaptation Strategies for Building Retrofit in Europe: Analysis of Co-Benefits and Trade-Offs

Retrofitting existing buildings can contribute to both climate change mitigation and adaptation, yet their interaction has received limited attention across several climatic contexts. This state-of-the-art review investigates retrofit strategies for the existing building stock in European climate zones. The screening process followed PRISMA-ScR guidelines and used Scopus as the database, with three researchers independently assessing the retrieved studies. After screening, 118 publications were analysed to identify research trends, while 48 were selected for detailed assessment of adaptation and mitigation retrofit strategies. The findings show that retrofit performance varies with climate and local conditions. For climate-responsive design, passive measures are still central, although their abiding effectiveness often depends on integration with active systems. Therefore, combinations of envelope improvements, solar control, passive cooling, and selected active technologies appear more effective than isolated measures. These strategies may also involve compromises between energy efficiency, thermal comfort, and environmental impact under present and future climates. The review identifies climate-specific relationships between retrofit measures and adaptation–mitigation outcomes. Current research is affected by climate zone coverage imbalance, insufficient attention to climate-induced hazards, and reliance on simulations. Further investigations should strengthen experimental assessment and adopt multi-hazard approaches considering durability, economic feasibility, and vulnerability.