Energy and economic analysis on retrofit actions for Italian public historic buildings

Highlights: • Application of energy efficiency actions on historic buildings. • Application of renewable energy sources on historic buildings. • Energy priority actions and economic feasibility in building efficiency. -- Abstract: According to the recent EU Directives on building energy efficiency, the Italian government is paying particular attention to energy refurbishments of buildings by enacting energy measures and obtaining significant results. In particular, the Italian government is providing economic incentives to citizens or public administrations that improve the envelope of the energy performance of a building. However, according to strict national regulations concerning building heritage, most actions cannot be applied to historic buildings, even though they represent approximately 30.1% of all buildings. In this context, the energy retrofits for Italian buildings are not simple but necessary. Therefore, in this work, a public historic building was simulated, and some permitted retrofit actions were applied to analyse the effectiveness of national measures in four different climatic zones. The results showed that the same applied action that reduces the primary energy consumption in some zones will significantly increase consumption in other zones, even if the zones fall within the same case-law. Finally, the results highlight two main unsolved issues: the renewable energy source installation of a historic building and a strong distinction between measures and economic incentives around the Italian peninsula, which has very different climate conditions.