Saint-Etienne, France

La Cité des Affaires

Grüner district – Zac Châteaucreux, Saint-Etienne

The site is a vital liaison point between the centre of Saint-Etienne and the new Chateaucreux neighbourhood, to which it forms a major entranceway. It also constitutes a pole grouping several government bodies that will set up there : Regional Development Authority, Tax Services, Epora, Saint-Etienne Métropole, and so on. Service and leisure facilities will also be part of the mix: shared corporate restaurant, café, tourism bureau for the metropiltan area.

The idea is to develop a long built ‘continuum’ on the site to interact with adjacent streets. A linear construction that rears up and unfolds but also hugs the ground line to form a low accessible building – one that opens spacious courts and lifts bold overhangs. Each of its large bays serves an access route: the main portal opens to the concourse on avenue Grüner, which draws pedestrians into the project in a sliding movement. A high ceiling shelters and magnifies this entranceway, which is the finest and largest of three. The other two large ‘ports’ open the project to the streets that irrigate the lot, interconnecting pedestrian itineraries in the area.

Our desire for continuity in construction does not simply reflect the idea of building a legible and unitary urban landmark, it also provides the flexibility that the project needs. In fact, the principle behind this continuum is to imagine a set of ‘communicating parts’ that enable the user-administrations to merge into a whole, one and all, and to evolve according to their needs in harmony with those of other tenants. The absence of breaks in surfaces will ensure that things remain open-ended, with the possibility of extending or reducing space.

The project is like a large ‘Aztec serpent’ rising on the lot. Its body has three identical outer faces, and an underside that is different: a skin of silvery transparent scales and a bright yellow ‘throat’, shiny and opaque. This dual treatment of surfaces obeys a simple logic shared throughout, which aims at expressing clarity in folds. Depending on these movements, the yellow underside is either a floating canopy or an interior vertical wall, accompanying internal pedestrian movements with its rich luminous presence. The nearness of so much gorgeous yellow brightens up pavements and glazed elevations, casting golden washes over them like sunlight…This is a project that is about bringing together yellow and grey, silver and gold.

Credits
Structure: Khephren
Façade: Arcora
Maîtrise d’œuvre d’exécution : Debray Ingénierie
Roofing / Finishings: Pitance-Lamy
Metallic framework : Baudin-Châteauneuf
Façade : Allouis

Figures
Surface : 25.000sqm
Length : 108 m, width : 43 m, max height. : 34 m
Cantilever 25 m X 20 m without any grounding support
Dates : 2005: design constest, 2006-2007 : studies, 2008-2010 : works, delivery : september 2010

Europaconcorsi Beta

La Cité des Affaires