© Arotcharen Architectes + Mathieu Choiselat

The housing association, l'Office 64 de l'Habitat has built a new company headquarter in Bayonne in southern France. The fact that the building is an ecological example is proudly presented for visitors to see. Green architecture is not merely a theme or topic it is taken literally. Indeed, the slender block of office accommodation, clad in a green ALUCOBOND® façade, looks like a greenhouse thanks to the additional glass frontage on the south facing side.

© Arotcharen Architectes + Mathieu Choiselat

The low entrance building in front of the slender slab has a "green roof" covered in vegetation. That is not only an image promoting feature, the exterior is part of a climate control concept which, instead of relying on a battery of technological services, prefers natural methods. Vegetation on the roof acts as insulation and stores rainwater. The space between the glass outer skin and the building façade acts like a temperature buffer for the building within. The solar energy collected there is almost sufficient to heat the offices without other WELL-WRAPPED power sources in a mild winter.

© Arotcharen Architectes + Mathieu Choiselat

In a hard winter, two fuel cells are used in addition, and the north and south office blocks can be heated independently of one another. In summer, on the other hand, heat built up in the offices is primarily prevented by using night cooling and by the switchable glass slats which let the wind in. The concrete construction's slow thermal behaviour and the sun protection, which is individually controllable in each office, ensure a natural, consistent temperature in the building. This means that only the meeting rooms require compact, decentralised cooling systems.

© Arotcharen Architectes + Mathieu Choiselat

The architects have focused on simplicity in their choice of lighting and materials. Good use of daylight, by means of limiting room depth and using glass walls, saves electric lighting. Materials are joined reversibly, the bare concrete surfaces are only partially clad. That improves the thermal behaviour of the building as well as the replacement and recycling options for individual materials.

© Arotcharen Architectes + Mathieu Choiselat

+ Project fact

Project: L'Office 64 de l'Habitat, Bayonne | France
Architects: Arotcharen Architectes | France
Construction: Office building
Year of Construction: 2011
Energy standard: THPE, très haute performance énergétique
Product: ALUCOBOND®, Colour: spectra autumn 915
Pictures: Mathieu Choiselat
Plans: Arotcharen Architectes | France

+ All images and drawings courtesy Arotcharen Architectes