This timber-framed building is located in Saint-Samson-la-Poterie in the Oise region (northern France), over Paris, and especially in the natural region called "Pays de Bray".
It was the barn of a landlord housing of the 17th century and it has recently been retrofitted and restored by the owner himself. A careful work on the materials and on the execution was made.
The barn is one of the case studies of the CREBA (French knowledge center for responsible retrofit of heritage building) website.
Before intervention, the barn was inhabitable because of its agricultural use. It was entirely empty, without floors, doors and windows. The original framework was in good condition but needed a few reparations.
However, the cob was in very bad state and was partially missing. Some pieces of the wooden-frame were also mouldered by lack of maintenance, especially wall plates and wooden poles, and had to be replaced.
There was no heating and no domestic hot water.
One particular objective of this project was to prove, by a real example, that it is possible to save this kind of rural heritage buildings, often destroyed otherwise and replaced by new buildings.
The owner wanted to restore the exterior of the barn, but also to achieve a good energy performance in order to live in there. The housing offers indeed 400 m² of habitable surface.
External walls: The ground floor and the first storey were insulated from the interior with 20 cm of hemp wool on wood frame. The exterior façades were rendered with a lime and clay plaster. Between the wooden frame and the render, the plaster is being processed at 45° to the outside.
This allows the wind-driven rain to be evacuated away from the wooden frame. The stone substructure and some part of the wooden frame were cleaned and repaired. The street facing façade was rebuilt as it was before.
U-value (post-intervention) [W/m2K]: 0,4 W/m²K
Windows: The barn did not originally have windows. About twenty openings were created on both façades, respecting dimension, location and rythm that can be found in other similar buildings. The windows are all wooden double-glass windows. The wooden front door was tailor-made by a local craftsman.
Existing window U-value Glass [W/m2K]: 5,0
New window U-value Glass[W/m2K]: 1,3
HVAC: Studies were conducted in order to choose the heating system, including geothermal heating. But the studied systems were beyond budget. The owner simply opted for a second-hand oil-fired boiler, that provides both heating and domestic hot water.
There are no radiator since the only heat emitter is the radiant floor heating from the ground floor. As the intermediate floor is not insulated and features a large hopper, the warmth from the ground floor can rise in the upper storeys and the radiating floor heating turns out to be sufficient to heat the 400 m² of the housing.
Read more about the case study here.