Built in the 1960s, the Cité Carl-Vogt is of particular importance to Geneva's entire post-war architectural heritage. lightweight prefabrication system for small reinforced concrete components, developed in Morocco since 1949 and based on a 60x60 cm grid. In addition to 450 dwellings, the Cité also houses a nursery, several restaurants, shops and offices. Following archival research to gather information on the construction process, attention turned to a detailed analysis of the complex itself, its history, and its context. Based on these results, a refurbishment project was developed to ensure the energy efficiency of the existing envelope without altering the original appearance of the buildings and preserving the characteristic prefabricated modular system, clearly