Almost half of all buildings in the EU were built pre-1970, before the adoption of energy-efficiency measures. Therefore, renovating them is necessary in order to keep pace with the EU’s current energy goals.

In this context, the RE-SKIN project aims at developing an integrated and multifunctional system for energy retrofit of existing buildings, organised in two main subsystems, roof and façade, combined with the building's HVAC system.

The roof is equipped with a hybrid photovoltaic-thermal system, which produces electricity and heat and at the same time thermally and acoustically insulates the slab beneath. Electricity, from retrofitted photovoltaic modules, powers the building's loads, which interacts with the grid and EV charging stations. Heat is used by a heat pump for heating and hot water preparation. Solar modules form the outer skin of the roof and replace traditional materials such as tiles and sheets. Through a special treatment, they can take on different colours, depending on the aesthetic and architectural identity of the building.

The façade is a thermal cladding with self-supporting panels and bio-based insulation, optimised for quick assembly without scaffolding, inside which the wiring for the new installations and earthquake sensors are housed. Retrofit techniques/components of existing windows are also included.

Both the roof and the façade are particularly resistant to weather and extreme climatic phenomena, as they use materials that are more resistant and waterproof than traditional ones. The HVAC system consists of a solar-assisted DC air-water heat pump, connected to smart-fancoils, which are designed to be connected to the building’s heating piping, but can provide both heating and cooling.

The whole system is designed according to a circular economy logic, using mostly recycled/bio-based/repurposed/refurbished materials, and is supported by a lifecycle cloud-based DSS and energy management tool, in order to maximise energy performance while reducing environmental impacts. The system can be applied all over Europe, as it provides renewable energy and participates actively and passively in the energy performance of buildings.