La valutazione ex-post di progetti di retrofit energetico sull'edilizia storica come supporto al processo decisionale

Balancing energy-efficiency goals with conservation principles is a core challenge in historic building retrofit. Real-world projects are the true testing ground, where non-ideal conditions and frequent compromises shape decisions and outcomes; therefore, analysing completed interventions is essential. However, in the current landscape, collections of case studies are often reduced to descriptive sheets, and the first analytical efforts in official guidelines, although valuable, are still insufficient for a structured ex-post evaluation of effectiveness. This paper proposes a methodological framework for the critical ex-post assessment of energy retrofit projects in historic buildings. Developed within the author’s doctoral research, the method is based on the collection and systematisation of about one hundred national and international case studies organised in a repository. The retrospective analysis was conducted through the lens of the Whole Building Approach, applied at two scales: (i) the overall retrofit project, read as a process; and (ii) individual building components, assessed from a project-results perspective. The framework enables a comparative reading of strengths, limits and conditions of applicability, transforming documented projects into operational knowledge that underpins a ‘Reasoned Handbook’ to support decision-making. By providing a transparent and replicable method for interpreting the effectiveness of past interventions, it promotes more informed, context-specific and conservation-compatible retrofit strategies.