Photovoltaic technologies in historic buildings and protected areas: comprehensive legislative framework in Italy and Switzerland

The launch on the market of innovative highly customized products, with a low visual impact colour and aesthetically wise promoted the integration of photovoltaic (PV) systems in protected areas. Despite the aesthetic, economic and energy advances, their integration therein is hampered by several legislative, and procedural barriers. For this reason, the study aims at reconstructing a European, Italian, and Swiss legislative and authorization framework to highlight prospects, potential, limits, and points of contact among such territories. The working methodology is structured in four parts: (i) the reference context's legislative analysis; (ii) definition of authorization processes; (iii) discussion with stakeholders; (iv) critical summary of the results. Thanks also to the introduction of specific targets and economic incentives, policies implemented in all territorial contexts push the use of solar energy in new buildings and restructuring. Several focus groups have been organized to discuss the existing legislation with different professional target groups (Heritage and Public Authorities, Designers). The results show that in Italy, due to the complex and fragmented authorization process, PV implementation slowed down over the years. In Switzerland, however, clearer criteria and simpler procedures encouraged their diffusion. In both territories, stakeholders need more training and updating about PV technologies, integration criteria, and implementation processes.