Dietrich I Untertrifaller architects, Vienna (AUT); Colas, Durand Architects, Lamballe (FR)
Built in a rural site in the municipality of Lamballe, in Brittany, this building is the product of a collaboration between the Austrian architects Dietrich | Untertrifaller and the local French firm Colas Durand.
Comprising a long rectangular wooden volume oversailing a curved glass and concrete base, the building faces the southeast towards open countryside. A product of Vorarlberg design rigour, the 120-metre long principal façade has a sustained rhythm of structure, fixed and protruding opening windows. The masonry plinth meets the hillside behind (where workshops and offices are housed); the opposite, front side is fully glazed. Technical elements, structure and interior atmosphere are fully resolved in a coherent whole, in which wood is omnipresent.
The plinth volume and stair cores are in concrete for reasons of thermal inertia, fire and seismic resistance; its curved curtain wall is by Raico with spruce columns. Upper level floor and exterior walls are in spruce CLT with exterior steel bracing crosses (floors are concrete-topped for acoustic and fire reasons). Wood is ubiquitous in finishes such as slats on the ceiling, horizontal cladding throughout the circulation, windowsills, exposed beams and furniture in the classrooms, shelving in three-ply panels on the ground floor, and wood-aluminium carpentry. Timber for secondary framing is locally-sourced.
Prefabrication allowed an 18 month build (fast for an 800-pupil school), with CNC milling direct from the designers. The choice of wood was one of the main evaluation criteria for achieving the objectives set by the high environmental quality label (HQE). The CLT structure has made it possible to maintain many light non-load bearing walls (between classrooms and solar greenhouses), which allow a reconfiguration without heavy works. Otherwise, the possibility of dismantling and separating the wooden elements has been favoured in order to facilitate end–of–life management, in the form of recycling.
Wood was favoured throughout for reasons of life-cycle and to eliminate the need for finishes such as plaster and paint.
Architect: Dietrich | Untertrifaller (Gerhard Pfeiler, Christina Kimmerle) and Colas Durand
Concrete engineer: Espace Ingénierie (Saint-Brieuc)
Wood engineer: QSB (Lannion)
Client: Conseil Général des Côtes d’Armor
Location: Rue de Dahouet, 22400 Lamballe (France)
Conception and realization: 2016-2018
Built area (footprint): 9000 m2
Photos © Luc Boegly