The Théâtre, a future national theatre, is a new landmark in the Carré Sénart. It finds its balance in a play on oblique shapes and a hierarchy of reliefs. The metal roof is laid like a veil on the fragmented volume that houses a large front room, an adaptable room and a restaurant. A group of squares of differing sizes, some pressed some perforated, give life to the aluminium skin and make this unifying envelope vibrate. In the centre of the building, an open-air patio provides light and natural ventilation. The aluminium skin has a protective function without the obligation for water and air sealing. This choice of design affords great freedom to the work on the geometric motifs characterising it.