Resumen
Current buildings are responsible for the highest energy consumption, exceeding polluting sectors such as industry and transports. In Portugal, a large part of the building stock was built in the 1970s and 1980s, but buildings dated from the 1960s and 1970s are the ones with the most anomalies and worst quality of construction and, therefore, worst energy performance. The renovation of those buildings can represent an excellent opportunity to correct and improve their energy deficiency and, with that, to promote a more sustainable building stock. The ETICS system is the most used for the renovation of buildings in Portugal due to its lower cost, quick application and thermal efficiency, but it doesn?t solve other problems that may exist, such as structural safety and interior organization of the existing building. The application of prefabricated systems in the envelope has proved to be successful in improving energy efficiency, allowing new volumes and extra areas while contributing to the structural resilience of existing buildings. This paper aims to describe the current situation of the buildings renovation in Portugal and to discuss the potential of innovative envelope retrofitting solutions, using natural materials like timber, and is more concerned with the problems of existing buildings and the need for comfort and space for the occupants.