The willingness of the developer and the planner for this island, from the competition phase is to position the project of high environmental quality and to include it in a PassivHaus certification. A passive residence is a virtually independent housing for its heating needs: it can indeed be content with solar gains, the energy released by the occupants and household appliances and good insulation. Requirements "induced" by the lens 'passivhaus' are numerous: controlled cost, design details, collaborative work upstream with all project stakeholders, etc ... These objectives can sometimes get in 'conflict' with urban requirements.
Nevertheless, facing south towards the Garettes Vallon in Orvault, in the Nantes area, the island site is positioned as a "balcony" opening on an open and green view, which is a North gazebo / South almost perfect 'proposal for a' passiv'haus'. The architectural layout is divided into three separate buildings, and supplemented by three semi-underground houses built specifically in the Park.
This fragmentation of the buildings can offer views sequenced from the street to the north, and soothes density 'supposed' of the project. The project focuses therefore a bioclimatic approach:
· Mixed concrete and timber frame structure is favored giving the building inertia necessary for any building to store heat and redistribute it, as well as to favor the acoustics between apartments,
· Double insulation from the outside and inside is provided with treatment of thermal bridges
· Looking for a compact and a cross of the volume of housing (for natural ventilation via opening on opposing fronts)
· Comfort ventilation recovering internal heat,
· Corridors and balconies in wood and metal structure detached from the primary structure of frames (to avoid thermal bridge)
The project emphasizes the concepts of ownership and residence by the will to get closer to individualized access for maximum housing, and by private extensions for each dwelling. Also, our project proposes to re-introduce concepts such as the fact to survey an alley, to borrow a gently sloping path to walk along a valley, crossing a bridge, to overhang another place, to go home.
For each building, the main access is by the north facade. The external walkways detached from the main structure, offer multiple views and promote life skills together. They generalize apartments crossing, double and triple orientation, without vis-à-vis and preserving the privacy of each.
On the ground floor, housing is accessible from the outside by a footpath off the ground, "pontoons" introducing a gradual distancing between the public and the private.
The buildings, corridors and terraces, are wrapped in a skin natural douglas blades purged sapwood, with alternating rhythm. South, Vallon side railings also describe an alternating rhythm: light metal floors and attic openwork chevrons.
In the North, Railing corridors are lighter, perforated metal, to pass a more homogeneous light. This allows to reduce the linearity and break the monotony of plain facades and cutting the frame in rhythmic sequence. This epidermis and provides a vibration chromatic facades and suggested thickness.
Material Used :
1. Aluminium joinery (doors, windows, Exterior Joinery) : "Kline"
2. Façade cladding : douglas wood by "Piveteau"