Retrofitting the residential building stock poses a major challenge for the European building sector in the coming years. It is also crucial to achieve the decarbonisation goals set by the EU’s Energy Roadmap 2050. The EASEE research project, funded by the European Commission, addressed this issue by developing a holistic approach to envelope retrofitting. This paper presents an innovative technical solution developed within this research project: a lightweight, aerogel-based wallpaper that can be easily installed on the inner side of perimeter walls. The system is composed of an aerogel-impregnated textile layer, forming the insulating core, and a fabric finishing that can be easily installed and replaced thanks to a bespoke tensioning d...