Traditional and innovative materials and solutions to improve the energy efficiency of historic windows: a literature review

During the last decades the improvement of the energy efficiency of historic built heritage has taken on increasing importance: this has led to the production of a great amount of research works within the scientific community. Among the building components, windows are commonly considered the weakest element of the envelope and, therefore, the first to be replaced in historic buildings. Contrary to what one may think, more “sustainable” solutions are possible: there are several strategies that can be applied to enhance windows thermal performance, sustainability and conservation without substituting them. Our goal is to outline the research state-of-the-art in this field through a literature review: to this purpose we collected many publications for a total of 126 documents. The result is a as complete as possible view of the research status on window interventions, with particular attention on problems and future perspectives of the high-performance materials integration in the historical context.