The Costil

Article D'A - n° 297 - April 2022

"The meeting with a private individual who had acquired a vast estate, consisting of a dilapidated manor house and its outbuildings, at Sap-en-Auge, in the Orne region, gave the team the opportunity to express its own vision, in complete freedom. "To get out of the regulatory framework, to test totally non-standard techniques, not always insurable, with 100% local materials", they claim in unison.

They very quickly convinced the owners not to undertake the long and costly renovation of the manor house, but rather to transform the adjoining 90 m2 farmhouse into a holiday home, which would allow them to consider the possible transformation of the estate over time. To do this, they propose to remove some of the bricks from the farmhouse, and then to build a wooden volume in its heart on the first floor, in order to accommodate a simple programme: a cathedral living room extended by an open kitchen, which is itself overlooked by a mezzanine office. The new wooden volume houses the bedrooms on two levels. 

[...]

Located in a rural area, the project to renovate the farmhouse - which is intended to be a short circuit - requires a physical presence in the area. Consulting the available companies and craftsmen, then creating a close relationship with the inhabitants and elected representatives requires a long-term involvement, to the point that the architects literally camped out on site for several months. They draw a map of the region, within a radius of 100 to 150 km, a map born of a clearing and meshing of both material and human potential. This long sourcing process precedes the architectural project. 

Their research into how to make the most of their know-how leads them to innovate, in a form of rural hacking. The craftsman who harvests chestnut branches on horseback and makes horticultural ganivelles is asked to make the house's cladding. The hemp industry and agricultural machinery are involved in insulating the roof slopes and in spraying 15 cm of hemp-lime insulation onto the walls. The hemp-lime spraying machine is equipped with larger nozzles to accommodate this type of mixture. The intermediate floor between the night spaces is made with 700 cattails, a mixture of green wood, local soil (slurry) and agricultural hay. The cattails were installed for a week by 15 volunteers - the only time the site was open to the public. Inspired by the traditional half-timbering of the Auge region, the framework is made of Douglas fir, surrounded by reused bricks, cleaned on site.

The whole of the wooden volume in G+1 rests on foundations without concrete or reinforcement. Technically, this is one of the most sensitive and experimental points of the project: the architects drove 12 black locust piles 3 metres long and 30 cm in diameter into the ground. The logs were manually debarked with planes and burned on the surface to become rot-proof. The piles were driven into the ground with an agricultural auger and rammed to a depth of about 2.5 metres. Finally, the heads were planed to the required level to accommodate the cyclopean foundations made of lime and flint only, thus allowing the creation of a ventilated hedgehog. The black locust was supplied by Forestiers Associés, a small family sawmill that also manages the rational logging of local forests within a radius of less than 30 km.
 

100% local renovation of a house in Costil with materials exclusively from the Pays d'Auge area:

• Reused clay bricks [0 km].
• Acacia wood pile foundations [40 km].
• Douglas fir framework [30 km]
• Hemp wool and hemp soil insulation [50 km]
• Rot-proof insulation made of reused cork stoppers [30 km]
• Cattails and raw earth plaster [0 km]
• Cladding in chestnut poles [120 km]
• Flooring in reused oak paving stones [220 km]

Renovation carried out by :

• Owner: SCI Le Costil
• Construction manager: Anatomies d'Architecture
• Timber frame: Depuis 1920
• Traditional masonry: Scheck & Déco
• Roofing : Grolleau
• Hemp insulation: Eco-Pertica
• Sawyer : Forestiers Associés
• Mex : Planète Mat

Ground floor layout - The Costil

1st floor layout - The Costil

AA' elevation - The Costil

BB' elevation - The Costil