— Administrative building for the Water Department

The site of the Vidy wastewater treatment plant (STEP) is composed of industrial buildings on its northern edge, creating a strong physical boundary. It is part of the larger Vidy area, formerly marshland that was filled in, with a deep historical connection to early Roman settlements.

The IMPLUVIUM project draws on these historical layers to propose a design that reinterprets the courtyard building typology, placing water at its center for both climatic and technical purposes.

In order to preserve the landmark status of the existing administrative building designed by Jean-Pierre Desarzens in 1967, the new project is conceived as a simple, freestanding volume whose façades do not seek alignment with the existing structures.

Instead, a conceptual and formal link is established by recognizing and reinterpreting key architectural features already present on site: the interior courtyard, horizontal window bands, cut-out corners, and the 240 cm structural grid.

The new window bands echo the principle of flexibility developed in the original building, and the use of aluminum, already present on the site, enhances the integration of the new volume.

Aluminum’s reflective properties are employed to create an image of a light, almost ephemeral building, subtly blending into its surroundings through a play of reflections.

The two buildings do not compete formally; rather, they establish an architectural dialogue by sharing elements that are interpreted in different ways.