Le Prisme (Aurillac Concert Venue)

Aurillac is at the edge of France's Massif Central mountain region. The site is a large paved field & not quite a plaza, not quite a parking tarmac - is situated near the city's main train station. This area is under regeneration to provide a stronger link with the city's historic centre. The building is a new venue for theatre, concerts, fairs and sports events. It contains retractable seating and demountable stage for versatility. The main space can accommodate up to 4500 people during performances. As it is never permanently inhabited, the building is essentially a chamber for ephemeral events. It is an instantly recognizable object. Three ribbons of concrete that vary in height and texture define the building. The ribbons delineate the different zones of the building: entry, hall, storage and back of house facilities. Their play also creates a series of residual spaces that contain services machinery and technical access. Inside, a twelve-meter high ribbon defines a rectangle that is the hall. The hall is column free, measuring forty meters wide by sixty meters long. Externally the upper ribbon is made of prefabricated concrete panels with a regular grid of glass bricks.

During the day, the sunlight plays with the 25,000 bespoke pyramidalshaped glass bricks, producing glimmering effects and dramatic shadows. In the evening the building awakens as the Fresnel lenslike surfaces of the glass bricks amplify the intensity of the coloured lighting scheme, producing a glittering facade. The façade's colour lighting scheme can be altered enabling collaborations with the spectacles inside. The lower ribbon is sixmeter high and made of in situ concrete. The undulations of this wall define the entry area and loading dock.

Like stage scenery or a flamboyant costume, the building is meant to be seen from afar. The majority of details are simple. It is by default a very robust building - a resilient structure that requires little maintenance. Within the hall, articulated lorries can drive inside; delivering performance and catering equipment or trade shows displays. At the same time, the assembly or disassembly of stage and retractable seating can occur.