The Tilleuls building is part of an open urban complex, a legacy of the modernist vision of the park city, which gives the district a green charm. Built in the 1970s, the building is to be thermally renovated while at the same time being part of a more global desire to densify the site. The building will be extended in height and in length, with the addition of a bay to the north and a bay to the south, on the built footprint of the car park.
The thermal renovation of the envelope is accompanied by a reflection on the habitability. While the original flats remain functional, the night spaces no longer correspond to current standards. Widely open to the outside in a “seaside flat” style, the flats have balconies that are too narrow to be really used. Thus, the creation of a new structure with large terraces allows the rooms to be enlarged at the same time. The resulting system of steps creates a rhythm in the background and offers a greater variety of appropriable exterior spaces.
The extensions both in heigth and in legth will take place on the actual footprint of the underground car-park. In order to keep the existing foundation system without the need to totally reinforce it, minimazing the total mass of the extensions was a priority. Structural timber seemed a natural choice. Another challenge is the constraint of insuring that the building can stay inhabited whilst being renovated.