A new administrative building at the STEP in Vidy brings together the various Service de l’Eau staff while seamlessly integrating the site with the Bourget Park. The horizontal extension of the existing building enhances outdoor spaces, delimiting an industrial center to the north and presenting an open facade to the south. It promotes team cohesion through bright, flexible workspaces. Built with a hybrid wood structure, the building prioritizes sustainability, natural ventilation, and passive thermal comfort. Green roofs and solar panels enhance biodiversity and energy efficiency. Natural materials and a compact design minimize the ecological footprint, while the cafeteria and shared spaces foster employee interaction.