Opting for straw instead of concrete; this is the challenge that has made the community of “communes du pays de Saint Meen Le Grand”, in France. This community, which grouped 9 municipalities has made this choice in order to have a green building. Marcel Minier, Mayor of the city of Muel returns to the concretization of this bright idea in an article on Basta website devoted to the construction of public buildings with straw in France.
A sharing of experience, which could draw the mayors and architects of the African continent. Indeed, in addition to being ecological, straw construction is less expensive than concrete!
Straw has the wind in its sails since 2012 in France. This is the result of the publication of the “professional rules”. It is a “technical document that describes the conditions in which straw must be implemented to an ‘official’ status: it is recognized by other professionals in the building industry, by the authorities and insurers’ explains the article.
“Straw is the insulating material which has the lowest carbon footprint,” said Coralie Garcia, co-President of the French network of the construction of straw. As another benefit of the straw, it was noted that it allows to construct passive buildings, promotes agricultural activity, is suited to all types of building and according to the experts, it has a longer life expectancy compared to concrete. Straw constructions also resist well to fire. “The tests carried out in 2009, before the construction of the school straw at Issy-les-Moulineaux, showed very good resistance to fire of this type of construction», says the article. In the municipality of Muel, there is a multi-home nursery, which was built with straw walls.
What a construction with straw looks like
The report written by Nolwenn Weiler indicates that a ‘straw construction includes a wooden structure, mounted on square that we then stuff with bundles of straw. It may also be made from prefabricated walls in workshops, arriving on-site already lined with straw and ready to install. The municipality of Muel has set his sights on the first method while the city of Montreuil, situated at 13 km from Paris, has opted for the second for the construction of a school with straw. During the construction of this school, the Town Hall had demanded a building that does not consume much energy. With straw, this school of more than 5000 m² produces more energy than it consumes. It uses solar panels to heat water, photovoltaic panels to generate electricity and recovers rainwater for toilets and garden.
Quality price ratio, argue for the choice of these communes who dared to bet the straw. Indeed, the Muel multi-host cost less than 2000€ / m2 to the community of commune, a cost below the «classical» constructions. At “Loire-Atlantique”, in Bouvron, a school 100% eco with mudbrick walls cost barely more than 1000€ / m2. “What makes it the least expensive school of France” ensure Local Authorities. Cost of operation, these buildings are inexpensive.
Mickaël Laurent of association « Bretagne rurale développement durable » (Bruded) gives a few tips and tricks in this regard. “We need more thoughtful buildings, no frills. Avoids unnecessary hallways, ceiling heights that are there only “to do good”, and convoluted – complicated forms from a constructive point of view – that often prolong invoices”.
Last advice to Local Authority before engaging in this type of construction: be super motivated and have solidarity because the construction monitoring is demanding. Thus, it seems simpler to launch this type of building in rural areas, where the works are often smaller and closer ties between local authorities and the professionals.
The original article is available in French here