12,000 manufacturing hours for the framework
The structure is made up of 8 curved roof trusses, supported by tie rods, spanning 35m. Some 160 jack rafters and 1,000 purlins make up the secondary structure that holds up the roof. The framework was built in VIRY's workshops (12,000 hours) then assembled on site using 20m-high shoring towers. Once the entire structure had been adjusted and the tie rods set up, the pre-stressing of the structure meant the glass roof could be removed from its shorings in precisely predetermined phases.