The 22 houses handed over in 2009 in the district of Les Toits de la Corvée in Saint-Dié des Vosges, a small town near to the German-French border, have been awarded with the quality mark for low energy buildings (BBC-Effinergie). The quality of this project, with whose implementation the architects Eric Schmitt and Antoine Pagnoux (ASP Architecture) were commissioned, shows that environmental protection and social commitment are not mutually exclusive.
22 homes, Saint-Dié des Vosges, France
DPLG Antoine Pagnoux, ASP Architecture
Sa d’HLM le Toit Vosgien
Koramic Datura, Natural Red
22 energy-efficient houses in Saint-Dié des Vosges
In order to realise the housing project with its 22 energy-independent units (eight houses in category 4 and 14 houses in category 5 with an average living space of 115 square metres), which meets the latest environmental protection requirements, five old houses built in 1956 had to be demolished first. The sloping site in the centre of the town (just 600 metres from the centre) also presented the planners with certain challenges. Due to their number, not all of the houses could be ideally arranged according to bio-climatic criteria and requirements for wheelchair-friendly access also had to be satisfied.
The objective of the building project was to build environmentally friendly houses with maximum energy performance and low incidental costs. The houses should be both economical and environmentally friendly – these criteria played a major role in planning their construction. In the end, a solid wood structure was chosen, with the outer wall insulated using a combination of clay, render and wood. The upper part of the external façades of the 22 houses (north-east facing and not exposed to the weather) is clad with spruce and Datura flat tiles with a flat visible surface, while on the ground floor, the façades are covered with a mineral external render. Each house took only four months to build, with the erection of the prefabricated walls and roof taking just two days. The planning of the various building phases was optimised to reduce the cost of transport to a minimum. The combination of wood, clay roof tiles and mineral render on the ground floor was intended to fit harmoniously into the townscape and at the same time take into account the neighbouring architecture.
The houses have controlled indoor ventilation and a wood burner. The burner is intended to heat the entire house and provide hot water at the same time. Only four cubic metres of wood are required each year to heat the house and produce hot water. In addition, four square metres of solar panels are installed on the roof. These are used in summer and provide 40 to 60 percent of the hot water requirement. The leak tests, which were performed on the first prefabricated houses using air, showed that the air-tightness of the buildings is somewhat higher than required by the BBC quality mark and even slightly higher than the standard for passive houses. The result is that each of the houses consumes no more than 60 kWh per square metre of primary energy per year.
A large amount of research was necessary in advance of the project, because all the walls and openings depended on the laying of the roof tiles, which were intended to produce a harmonious overall appearance. These aesthetic considerations were decisive for the use of this unique material for roof and façade, from which the architectural homogeneity of the property can be read. “We decided to use the Koramic clay roof tile Datura, firstly because we obviously had to pay attention to costs, but also because of its durability and resistance. Over time, the material acquires a patina which emphasises the traditional character of the roof. The natural red colour gives the building a friendly, warm appearance. It is a colour that goes perfectly with this residential district and is found in 95 percent of the roofs,” explains Antoine Pagnoux, the architect of this project.
Expectations and demands are high, the wish list is long. This presents architects and clients with complex challenges. In consideration of the demands and expectations relating to quality of living, indoor climate, health and energy-efficiency, bricks, clay blocks and roof tiles prove to be very valuable building materials.