This project involves rehabilitating a former parking garage into a residential complex. Our guiding principle was to retain the existing building in order to preserve its architectural qualities; repurposing the existing structure significantly reduces the carbon footprint compared to a conventional demolition-and-rebuild operation. On the top three levels, a rooftop extension crowns the building. We decided to keep the existing building in order to preserve its qualities; this reconversion of the existing structure allows to significantly reduce the carbon footprint compared to a classic demolition/reconstruction operation. On the last 3 levels, a new elevation crowns the building.