Retrofitting the existing envelope of residential buildings: innovative technologies, performance assessment and design methods

The refurbishment of the residential building stock is a major challenge for the European building sector in the next few years. A retrofitting strategy considering only the improvement of energy performances represents only a partial answer to the overall target of sustainability. Prefabricated solutions for inner or outer envelope can reduce impact on inhabitants’ life: lightness, fast and easy assembly techniques are the major concerns. The paper shows some concepts for façade retrofitting aiming at the preservation of the building envelope exterior features – or at the improvement of architectural features whenever possible – with a reduced extra-load on the existing structure and a reduced impact on the occupants. These concepts must guarantee the quality and the performance of new building envelope, offering high insulation value, air tightness, excellent comfort and visual quality. The design process, developing from the assessment of the existing conditions to the detailed design of solutions and installation procedures, is highlighted.