The methods of constructions of habitat in Europe of the North-West evolved/moved relatively little since the appearance of the first villages of the Neolithic era until the modern time. Appearance of new materials not making disappear oldest. Thus cob, argillaceous ground mixed with chopped straw or hay, and plated on a mattress (flexible interlacings of branches: wicker, willow, hazel tree) will perdura like way of producing the hollow block (filling of the walls of the wall) until XIXème century in the houses in sides of wood (half-timberings) appeared at the average age. This type of habitat was not built to last, even if a house with the structure of wood, the thatched roof, the walls in cob and the wood base or bricks, built well and maintained well could hold more than one century. In the same way, the use of thatch is proven during more than 7000 years and almost until our days. The use of a breeder material vegetable and perishable can appear to us surprising, but is to forget the importance, at the beginning of the history of our companies, the house " for nothing ", relatively easy to build for little that the materials are found on the spot and that many people stick to her realization. This points out the importance of the community and its links of mutual aids. Thatch thus, made up of reeds in wet medium, collected in winter, or of cereal straw, could be assembled in boot or untied layers, and be attached to the frame on a lathing tightened by links of cord or hazel tree. Thus a minimum roof with the slope of 60° was degraded only of 1 cm per annum. A thick thatched roof of 50 cm could thus last about fifty years.

Neolithic era until around the Year Thousand, the most current form is a dwelling house of average size (from 8 to 12 meters length), reserved for human and surrounded by appendices more or less many and more or less vast which shelter the essential functions of an agricultural unit: domestic animals, food reserves, domestic and artisanal activities varied. The second type of habitat of this zone is a masonry of big size (often more than 20 meters) sheltering under the same roof men and animals, primarily of the bovines (sometimes several tens of heads): as in the preceding case, several appendices were built around this vast construction, but often of more reduced size. These masonries had as a structure an assembly of posts and poles barked but not squared. But the quality of construction evolved/moved nevertheless starting from XIème century with the use of squared beams and the evolution of the modes of assemblies passing from the link of cord to the technique of the tenons and mortises, authorizing a complexification of the architectural forms.

Since the summer 1998, organizers of the GRAAL frame construction by young people of structures of the High Age Means: Espier (attic with elevated corn), artisanal Ateliers of type " melts of hut " out of wooden, thatch and cob. They thus were confronted with the reality of the small building site of construction which although not requiring particular technical skills shows the importance of the planning of the tasks and the supply materials. Indeed once the structure of wood posts assembled, it is the thatched roofing which should be carried out, without forgetting that if the cereal straw is cut the summer (with the sickle) the reed is collected the winter. The plating of cob on the mattress being made only one time its setting out of assured water and by remembering that soaked clay several weeks is worked more easily than coldly extracted.

 Structures and torchis Thatch roofing