Architects : Patrick Arotcharen Architecte
Project Architect: Maider Galant
Area : 3494 m2 (Net floor area)
Photographs : Vincent Monthiers and Mathieu Choiselat
Introduction
The housing association ‘l’Office 64 de l’Habitat’, decided to build their new headquarters in Bayonne, a city active in its construction of social housing, in the South West of France.
It was here, on a green densely planted site overlooking the Adour river from the hilltop, that the client decided that they wanted to bring together all their services under one roof creating a kinetic and graphic object housing two main functions, a new exciting public space and the workspace and hub of the social housing programme.
The project itself follows several strong primary moves. It cuts the site in two, defining the southern side as the public ‘front’ leaving tucked away the northern service side dedicated to staff parking, delivery facilities and site management. The building sits aligned east west, parallel to the main road, placed between the majestic sycamore trees, planted to the north and south façades. The private access road peels off the main road carving a groove within the grounds. This rivalry between the vegetative mass and the built front creates a tension that dramatizes the site. The organic form and composition of the built element projected out eastwards opposes that of the grouped office spaces, arranged over 3 floors, and the public reception spaces on the ground floor.
The proposed architecture mixes fluidly and harmoniously, the external landscaping, the built façades and the integrated ‘roofscapes’, in one composition forming a rhythmic dynamic sculpture. This object built into the arc of the ‘avenue de Prissé’ thus becomes that of a kinetic discovery. It accompanies the fluid movement of the passing vehicles.
The architectural expression becomes even more apparent through the high environmental and technical design of the building’s skin. Not only does the skin have a real ecological function, it acts a tactile, instructive and didactic surface. The south façade take the form of a double glass skin filtering light and heat energy. The solar and ventilation louvers coupled with the small opening sections of the façade work together to compose a moulded, layered façade, protecting and controlling the internal ambient environment. It was important to create a non-typical office hub designed specifically for the users within; an object, which opposed the formal office conventions. Here the written and spatial architecture privileges comfort, transparency, warmth of building materials and naturel colours and tones. We wanted to create an object made up from an alternating sequence of opaque and transparent experiences, adding depth and perspective to the outlook from the internal workspaces and vice versa, at the same time conserving an aspect of intimacy. This tactile, surface layering adds to the kinetic and sculptural form of the building whose external skin changes with each external movement.
Structure and skin
Over almost 3500m2, the building rests along a supporting concrete spine however the ground floor public spaces and the 3rd floor management office spaces are built in entirely using structural timber, where a system of columns and supporting beams sets up a grid like rhythm, spaced at 60cm intervals. Using timber as the primary and/or secondary structural system to set up a dynamic within the building and coupling this with a living, breathing ever-changing façade, which reflects the surrounding landscape, lends itself to a building rich in detail and experiences.
As the client was particularly interested in producing a building highly energy efficient, both the structural solutions and the breathing external membrane were designed and developed with great attention. The inertia created by the structural mass of the concrete couples itself with a highly performing building envelope. The building in itself has been treated much like that of a green house whose insulating double skin not only reflects its surroundings but stores up energy in winter recycled within the internal ventilation system in order to heat the workspaces. In the summertime, the louvers open up, letting the building and office spaces breathe with a naturel ventilation system. These louvers open naturally when the temperature reaches a certain maximum ambient temperature. The composite façade panels are fixed at an angle which produces and interesting three dimensional surface which follows the same setting out as that of the timber structure and also creates an undeniable graphic effect. Additional solar protection is provided through the construction of external walkways between the two external skins, wide enough to ensure the upkeep and servicing throughout the building and through the installation of multi-coloured angled (45°) timber-cladding boards.
The building has a very high-energy performance rating.
