Architecture: in Alsace, the Heliodome was born, a “solar house” to respond to the climate emergency

In the village of Cosswiller in Bas-Rhin, a house stands out against the landscape. A kind of giant spinning top made of glass and wood called the Heliodome. This unusual dwelling is designed to hug the sun’s rays and reduce its heat balance to a minimum. An innovation that enabled its inventor Éric Wasser, cabinetmaker and designer, to win the Lépine prize in 2003 with this concept.

The strange building has on one side a south-facing glass roof of nearly 160 m² and 10 meters high inclined towards the ground, on the other, a large roof also leaning. An inclination measured according to the latitude of the place of construction, to get the most out of the sun according to the daily and annual trajectory of the star. Thus in winter, the rays illuminate the canopy to warm the habitat and in summer, the sun shines on the roof of the building equipped with small windows.

The interior of the house benefits from daylight while maintaining freshness. “In winter, the Heliodome covers up to 80% of thermal needs, but I sometimes have a small fire in an auxiliary stove”Explain Eric Wasser at AFP. No need for a radiator or air conditioning, thanks to the inertia of the structure and its insulation in wood wool mixed with cork.

A device that begins to seduce the public, many visitors regularly come to visit this architectural UFO. I was seduced by the shape, the architect is the sun!“, explains Herbert Lötscher, a Swiss cabinetmaker who had a Heliodome built in the Valais a few years ago. Even if he recognizes that the futuristic style of the structure can put buyers off, “when someone comes up with another form, it always takes time for people to click“, he admits.

But for its defenders the building remains “one of the best answers” to the climate emergency, adds Rémi Mammosser, promoter of the Heliodome. For the moment, about ten constructions of the same kind have seen the light of day, in France, Switzerland and Germany. To facilitate large-scale projects, it was urgent to “translate scientifically” the thermal qualities of the house to prove the solidity of the project to the most reluctant.

Thus an engineer is in charge of designing calculation algorithms and another will soon be hired to answer questions related to the structure of the building. In Savoie, three houses, a dozen lodges, a reception hall will soon see the light of day and a building project for a bank is also under discussion.

An inclination calculated on the latitude of the place to take advantage of the evolution of the movements of the sun throughout the year. (PATRICK HERTZOG / AFP)

Architecture: in Alsace, the Heliodome was born, a “solar house” to respond to the climate emergency