Energy Functional Retrofitting of Historic Residential Buildings: The Case Study of the Historic Center of Perugia

AbstractThe built heritage is characterized by an average low energy performance, but it is often excluded from studies and retrofit scenarios. In Italy, as in Europe, the building sector is the most energy consuming and pollutant. Italy accounts for 40% of the European historical heritage, which is not concerned by the building performance legislation. The description and the analysis of the residential building stock is the object of this work, presenting an overview of the historical typologies built since the XII century. The case study is the entire historic center of Perugia. A major step was to choose a qualitative methodology that combined together four main approaches in order to categorize the all ancient buildings in the old town: (1) historical documentation and municipal documental information (2) in situ investigation; (3) surveys to the occupants; and (4) infrared thermography. The first approach allowed to identify five typological archetypes while the subsequent steps allowed to define sub-typologies relatively to energy performance. The knowledge of the characters of the old manufactured buildings is crucial to improve the energy efficiency of the built heritage