ClientJacques Fétis – SCI Crucy
Main ContractorsArchitect: AIA Architectes
Engineering + economy: AIA Ingénierie
Environmental expertise: AIA Environnement
Scheduling, Overseeing, Coordination: AIA Management
ProgrammeRehabilitation and extension of the Salle à tracer (1915) of the former Dubigeon shipyards in order to welcome the Architecture and Engineering office of AIA Life Designers.
250 collaborative work stations, all fields included, with an aim to provide shared architecture.
Surface(s)2,770 m² of floor area on three levels (Ground floor, +1 et +2): 2,310 m² in the existing building / 460 m² in the extension
Cost€6M (cost of works, excluding furniture)
TimelineDelivery January 2017
HQE Office Building certification, RT2012 – 50 %
HQE Excellent Certification
2018 National Prize for wood construction, in the category “Equipment rehabilitation”
Located on the banks of the Loire, the Bas-Chantenay site is an urban renewal territory redesigned in its entirety by the urban planner and architect Bernard Reichen, as well as the municipal office for urban planning. The location is a mutating post-industrial territory whose original function, (construction of steel hull boats in the mid XIXth century), was transferred in 1969 to the Island of Nantes, and then to Saint-Nazaire in 1986. La Salle à tracer is a century-old building, iconic of Nantes’ shipbuilding industry. The building was used to support the production of ships. That’s where workers drew the boat hulls to scale 1, and then used the drawing as patterns for cutting the sheets before assembly in the dry docks. A remnant of this practice, the Salle à tracer is actually a vast 800 m² drawing table. The drawers drew the blueprints on the ground, a wooden floor now classified as a Nantes heritage site and whose scarified surface, dotted with brass markers, bears the mark of its past activity. The “simplicity” of the original building calls for a “simple” work of rehabilitation that aims to preserve its original shape and industrial dimension. In order to conserve the longitudinal strength of this nine-storey building sitting perpendicular to the Loire, the project proceeds by “elementary” extrusion of its iconic shape on the city side, which allows the building’s new function to be understood, thanks to this modern contribution. Via a meticulous and patient restoration of the significantly corroded concretes, the project reveals the concrete structural grid as it was in 1915, thus sublimating the hive-like structure, in which each of the irregular cells is home to a wood-aluminium joinery unit manufactured in the workshop and covered with natural zinc. The building preserves, for a new cycle of use, the classified floor of the Salle à tracer by protecting it with an overlay. However, the floor will remain visible through windows or portholes.
Three axes of resilience
Passive bioclimatic device that leverage:
– the flow of the river Loire (geothermic) with submersed devices that capture aquatic winter thermal units;
– maritime wind (natural ventilation thanks to the Loire airstream) in order to mitigate summer heat;
– natural light (breathable window frames and electrochromic glass that regulate solar intake).
Restraint in construction:
– bio-sourced materials from the wood and clothing recycling branch (such as Métisse, an insulator produced by the reinsertion organisation called Le Relais). The total volume of these materials amounts to 240 dm3/m², making la Salle à tracer a low-carbon building;
– the existing floor on level 1 was used to “wallpaper” the reception on the city side. The original “refurbished” steel structure was used to shelter the rooftop volume.
A design that fosters collaboration:
– shared functions (reception, cafeteria, large meeting rooms and workshops) located at the extremities of the ship-cum-building (facing the Loire and the town);
– on each of the three levels, there is a mixed system associating modular landscaping on the west as well as collaborative spaces on the east (small closable offices for impromptu meetings, telephone calls or simply to isolate oneself in order to better focus).