Reducing energy consumption and CO₂ emissions from building air conditioning is a major challenge for the European Union, particularly in the residential sector, which represents one of the highest contributors to global energy use. Although several european and national initiatives promote energy retrofitting of existing buildings, selecting the most effective efficiency measures remains complex due to the many variables involved. This study proposes a decision-support methodology based on multi-criteria Copras method to identify the most suitable energy retrofit actions for existing residential buildings. The approach evaluates multiple factors, including investment costs, energy savings, environmental impact, and payback time. The methodology is applied to a set of residential actual buildings located in different climatic and urban contexts across the Sicily region (southern Italy). The results demonstrate the effectiveness of the multi-criteria approach in supporting designers and stakeholders in prioritizing retrofit strategies aimed at reducing energy demand and environmental impact. The proposed procedure is easily replicable in other mediterranean contexts.