“A climate-neutral and united city”: a building without heating or air conditioning built in Lyon, a “first” in France
|A residential building project, capable of maintaining a comfortable indoor temperature without the aid of radiators or air conditioners, will be completed in 2026 in Lyon. Julian Hochgesang/Unsplash
A residential building project, capable of maintaining a comfortable indoor temperature without the aid of radiators or air conditioners, will be completed in 2026 in Lyon, for the "first" time in France, its initiators announced on Thursday.
Built in the south of the city, in the developing Confluence district, the “Essentiel 22-26” building will be “emblematic of a climate-neutral and united city”, said the Green president of the Lyon Metropolis, Bruno Bernard, during a presentation of the project.
Designed by the Austrian architectural firm Baumschlager Eberle, the six-story building, currently under construction, will be able to maintain an indoor temperature of between 22 and 26 degrees all year round “without using a conventional heating and air conditioning system”, promises the developer Nexity, which is carrying out the project.
In the cold season, the heating of the rooms is ensured by "the body heat of the occupants and that released by lighting and household appliances, for example,” architect Mathias Bernhardt of the Baumschlager Eberle firm assured AFP.
Natural ventilation
When it is warmer, cooling is done by natural ventilation with a shutter controlled by software that measures the temperature, humidity and air quality in the building via a network of sensors.
Finally, its walls in “60 cm thick honeycomb bricks” and its windows “triple glazed” must provide optimum thermal insulation and guarantee by “inertia” the restitution of this interior temperature of around twenty degrees, according to Mr. Bernhardt.
Already tested in Austria and Switzerland since 2013, “L'Essentiel" will be part of a set of eleven buildings dedicated to housing, commerce and education, delivered between the beginning of 2026 and the end of 2027, according to Nexity.
L'"Essentiel" will finally offer 23 apartments for purchase at moderate prices, at 3,000 euros per m2, the land remaining the property of the Foncière Solidaire du Grand Lyon under a real solidarity lease (BRS). A second building of this type is planned for 2028 in La Garenne-Colombes (Hauts-de-Seine).