The new educational hub “Goutte de St-Mathieu” in Bernex consists of four buildings and an underground car park. The complex includes the Social and Health Training Centre, the Secondary School, and two multipurpose sports halls. A covered trench is planned to provide vehicle access to the logistics hub and parking area, as well as a covered pedestrian passage connecting the logistics centre to the car park.

The load-bearing structures are unitary, simple, and rational. They also fully integrate environmental considerations through the use of renewable construction materials sourced locally or directly available on site, such as timber, recycled concrete, and earthen concrete. The buildings feature reinforced concrete bases supporting superstructures made of timber and steel according to the structural requirements. The floors are constructed using hybrid timber–earthen concrete slabs produced from the site’s excavated soil. The transition of structural grids above the parking and logistics areas is achieved using reinforced concrete transition slabs with beams. The buildings are founded on general rafts with local thickenings under vertical supports. Lateral stability is ensured by reinforced concrete cores.

The use of earthen concrete enables a 55% reduction in greenhouse gas emissions and a 60% decrease in energy consumption compared to conventional concrete, without significantly affecting the project’s schedule, costs, or site organisation.

Excavations reach depths of up to 10 m, supported by nailed walls and Berliner walls. The project and construction phasing have been developed to enable a circular soil management process, with most of the excavated material reused directly on site.