Urban renewal and retrofit actions in the existing building stock are, especially in the housing sector, a necessary condition to meet the energy reduction demand and, at the same time, a great opportunity to develop sustainable and responsive strategies in order to face the economic, cultural and social changing most cities are running into. The transformation of the building envelope can become an opportunity to rethink the configuration of the building through architectural and technological additions. This paper presents the methodological outline of a study carried out on some energy upgrading of existing housing buildings concerning the use of architectural...