Building energy retrofit: a multi-technology and low-impact renovation package

Energy retrofit and decarbonization of buildings constructed before 1990 is a key priority, since they still represent the majority of the European stock, having high energy consumption due to poor-performing envelopes, obsolete HVAC systems, and limited integration of renewable energy sources. To such aim, the EU-funded RE-SKIN project, which stands for Renewable and Environmental-Sustainable Kit for building INtegration, consists in a multifunctional retrofit toolkit composed of envelope technologies and smart HVAC systems that work synergistically to transform conventional buildings into energy-efficient and climate-resilient constructions. Based on a whole-building performance approach, the toolkit is designed to achieve high levels of energy efficiency and environmental sustainability, especially in areas of Europe experiencing increasing energy demand due to climate change. Interoperable building technologies and installations are also integrated: envelope solutions (thermal insulation and windows) ensure a reduction of thermal loads, while technical systems (BEMS, BIPVT, heat pump, fan-coils, power controller, storage systems) ensure energy efficiency and RES exploitation. The toolkit provides energy savings, optimization of energy fluxes, improved comfort, integration with the electrical grid, and circularity in material use. This paper describes the preliminary results of the toolkit application on two case studies, showing that the zero emission and net zero targets are fully achievable.