Vertical extension in rue Hoffmann, Geneva
Location Genève, GE
Date 2018-

Competition by invitation - winning project


Julien Charmion-Henry
Jules Chabbey
Charlotte Prins
Romain Dubuis
Grégoire Martin
Dan Relecom
Camille Wernli
Grégory Dos Santos

The project is located at one of the city’s major road junctions at the intersection of Route de Meyrin and Rue Hoffmann. Constructed in the early 1950s, the building defines the corner. The proposed vertical extension consists of 2 new floors, incorporating 32 apartments, superimposed directly on top of the current building. The vertical expansion is formed of a light, mixed structure. The stabilizing structures added at the level of the lift shafts are designed to take up a significant proportion of the total stresses. The presence of this new framework reinforces the construction’s overall wind stability and improves its seismic behaviour.

Designing a vertical extension implies selecting a response to the question of its relationship to the existing architecture, namely: a) to conflict with it and act in contrast (UFO strategy), b) to reproduce the same architecture to conceal the vertical expansion (chameleon strategy) or c) to draw inspiration from it, adapting and reinterpreting its forms to create a new architectural structure that refers directly to the original building. The latter solution has been adopted here.

The current facades are renovated simply by treating the concrete and changing the windows and blinds. A grey-beige paint is subtly applied, accentuating the structuralist grid elements through darker tones. The apartment block consequently regains the appearance of similar ones of its generation.

The heightening consists of a metal structure with near-black anodized aluminium cladding with bronze tints, reminiscent of the architecture of Mies van der Rohe or that of the Genevan architect François Maurice. The choice of a dark-coloured elevation is also more discreet, less dazzling, especially in sunshine, and refines the raised structures. The heightening’s two extremities are concave, thus forming an allusion to the convex shape of the present building.

The building’s rear courtyard offers a plot for a project whose attribution has been left open. A small, very simple and rational two-storey building plus attic is proposed here as student accommodation, whose architecture resonates with the adjacent main building. The three interventions all harmonize perfectly with each other in terms of structure, materials and colours.