Shape-determining supporting structure with tripartite grid lattice support made of fir wood
In 2004, the small community of Borex on Lake Geneva and the neighbouring community of Crassier held a design competition for a new double gymnasium. The result was a glass cube. At first glance simple and abstract, it fits into the site’s irregular topography.Its volumes and proportions echo those of a pre-existing sports hall belonging to a larger school complex, to which it is connected via a low passage. The new double gymnasium’s interior is dominated by the tripartite grid lattice support made of fir wood that provides the building’s load-bearing structure. It contrastsvisually with its glazed outer shell. This support framework of slender, closely placed, crossed diagonal rods is 5.80 metres high and is supported on both sides by concrete walls clad in triple laminate board, which transfer the vertical loads. The girder runs along one side of the hall lengthwise, extending across the hall’s full length of thirty-two metres like a beam. It spans a support-free panoramic window that provides the hall with natural daylight and connects its interior with the outside world. This light-permeable and grid-like load-bearing construction looks different, depending on the light incidence and time of day, owing to the etched matt glass of the profiled facade that is mounted on it. High-performance requirements – maximum load capacity, minimal deformation and high precision – made prefabricated elements the intelligent choice. Automatically controlled ventilation flaps, arranged between the external glass skin and internal load-bearing construction, channel the warm air out of the building, creating a comfortable atmosphere within this hall with a grid framework as its major constructive design and atmospheric element.