Client: Ville de Nanterre
Architects: Barthelemy Grino Architectes SA, Paris
Engineers: RFR, Paris
Contractors: Charpente Houot (SAS), Gerardmer

Douglas fir, a naturally durable sapfree material, is used to create the simple grid structures that form the roofs of these stadia. Thin solid laths of Douglas fir are connected neatly to one another in relatively short lengths. The major elements, including the round propping struts, are Douglas fir glulam. The rear-facing balancing canopy is tied down using steel rods.

The complex geometry was achieved using computer generated design linked to computer assisted manufacture. The result is a very lightweight network, with a fircoloured natural finish that will weather to silver. At each node connection, the fasteners are sensitively detailed to complement the precision and airiness of the whole structure.

The shell was fabricated in sections in the workshop. The prefabricated units are rectangular in plan, each with an outline of 2m x 10m. Tapering ribs are suspended from the upper rectangles to create sets of v-shaped trough profiles. The fine grillage is arranged in a triangular latticed format, giving in-plane shear stiffness. The boundary shape comprises a doublycurved envelope, which is displayed in the completed structures thanks to the translucent roof coverings.