Small movable and recombinable dodecahedral units, called "éclaireuses", are available for use as, for example, dressing rooms, offices, technical annexes, installation spaces, or even parts of stage sets. Since the building is surrounded by over 100 residences, acoustic isolation was a high priority. It was designed using the "box within a box" principle. The performance spaces, being the most sonically intensive, were placed in the center and are surrounded by three successive layers of more external spaces. Utility spaces and vertical passages are located between the two outer layers. There is only one "ceremonial" staircase connecting the ground floor and the first floor. Otherwise each floor is as large as possible to provide the greatest flexibility in the use of the space. Performance venues The Large Hall (Grande Salle) is above the main floor at the back of the building, has a capacity of about 750 standing places or 308 when seated. It includes telescopic tiers (bleachers) for seating which can be folded away sideways. Projection screens can be mounted at various levels on any of the four walls, and a large variety audience and stage setups can be accommodated. There are also four large screens the size of each wall which allows for the possibility of total audience immersion in a projected space. The exterior is covered with mirrored panels, rendering it instantly recognisable and capable of complementing installed artwork. The Small Hall (Petite Salle), located on the lowest level at the back of the building, can accommodate 70 seated and 150 standing places and can be used in conjunction with the exhibition areas or as a separate audio/visual venue. The walls can be taken apart, and the floor panels can be mounted at different levels to create various platforms and tiers. The colour scheme is in shades of gray so as not to conflict with the artists' installations. The Auditorium is more traditional with 130 fixed seats, a projector and control room, and a 5-metre screen at the bottom front of the hall. It is located between a large exposition space on the lower level at the front of the building and the petite salle at the back. There are entrances on the ground and first floors, and it is directly accessible from the rue Papin. Resource centre The resource centre functions as a modern library. It is located at the back of the building, above the Petite