The retrofitting of buildings is crucial to achieving the EU's climate neutrality goal by 2050. The Renovation Wave plan targets upgrading 35 million inefficient buildings by 2030, requiring innovative solutions.

This paper, titled ‘From energy-intensive buildings to NetPlus targets: An innovative solar exoskeleton for the energy retrofitting of existing buildings’, introduces ‘en-SʘLEX,’ a solar exoskeleton for energy-efficient retrofitting. It features a self-supporting steel frame with passive solar control and active PV systems. Its modular design allows external installation without disrupting occupants.

Simulations on a Mediterranean residential building show energy reduction of 33.4% for heating and 25.5% for cooling, reaching 80.7% and 60.5% with generator replacement, making the building a NetPlus energy producer.