An innovative space in a rural environment

Benoit Rougelot, November 2019

Intentions and attentions

Faced with the crisis situations that our society is going through today, it is becoming urgent to work together to give meaning to the life of our territories and its inhabitants. Innovative economic activities, social solidarity, environmental concerns and shared governance are the pillars on which we must rely to co-construct our actions. This is the framework of the action carried out by the commune of Brangues, which has led to the creation of an innovative space in the rural environment.

It is a multifunctional public facility comprising a nursery school, its protected courtyard, a primary school, its courtyard which is also a public garden, the school library which is also the village media library, a games library which is also the cyber-café, and a room for the gardeners who look after the shared vegetable garden adjoining the communal garden. In short, a concentration of uses that allow meetings and the animation of a small community.

Achievements

The project adapts to the topography of the site. At the foot of a hillside, the ground floor building houses a media library and a games library, which are open to the public and operate beyond school hours. The primary schools on the first floor opens onto the sloping garden and the nursery school on the second floor is accessible via a wooden footbridge that links it to its courtyard, which overlooks the site. The natural gradient of the site allows separate access to each floor and each programme.

Unfortunately, the limited budget of the municipality did not allow for the redevelopment of the school’s surroundings. Nevertheless, the two existing courtyards and the public garden provide play areas. The flower meadow on the green roof also enhances the biodiversity areas.

The use of straw bales in rural areas is more than obvious: it should be compulsory. The built heritage of the village of Brangues is mainly adobe housing. It would have been indecent not to pay tribute to this formidable construction technique which has many assets (aesthetics, visibility of labour, hygroscopic regulation, inertia, ecological impact…).

A central core of cement concrete bracing wooden slabs between which wood-frame walls filled with straw bales create a case, clad with wood on the outside and padded with earth on the inside. The earth coating - which only asks to be caressed - contributes to the thermal comfort of the building (inertia, vapour barrier, regulation of hygrometry). Similarly, the non-load-bearing adobe south facade - the work had to be carried out in 9 months all inclusive, the wooden skeleton was erected before the adobe overhangs, so it does not rest on the latter - and is not insulated, in order to take advantage of its thermal inertia and play the role of a hygroscopic and thermal regulating wall and shows without veil, by its successive layers of rammed earth, the craftsman’s work.

The search for resilience in the technical elements led us to ban electric controls for the blinds and prefer natural ventilation for the classrooms. On the façade, 12V servo-driven louvres open and close according to the CO2 level measured by sensors, while in the heart of the building, full-height ducts create a natural draft. A biomass boiler, fuelled by wood from the communal hedgerow pruning, meets the heating needs while contributing to a relatively low primary energy balance.

Improvements

We have therefore designed and built a building using wood, earth and straw - in short, building and public works - whose materiality we are revealing. We would have liked to have a short circuit for these materials and to have been supplied in the commune. But the carpenter had his own local supply chain. The excavated earth on the site, essentially composed of fill, was not very suitable for plastering or adobe, and no earthworks of sufficient scale were taking place at the same time in the commune. The local roadworks company was nevertheless able to supply us with earth 80 km from the site. And the local farmer was not equipped to supply us with bales of straw of the right density.

Whatever the project, we try to have a global vision of the stakes, of the interactions between the different actors (users, financiers and companies). This creates an ecosystem that is often fragile but tends to consolidate each time a new resilient project is carried out. The knowledge and examples of earth and straw projects accumulate and reinforce each other.

In our future projects, the adobe will be load-bearing, the laying of earthen plaster will be the occasion of a participative building site, the green roof will be accessible and the natural ventilation will be with heat recovery.

Sources

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