Construction in Lyon of a building without heating or air conditioning, a "first" in France

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 environmentalist president of the Lyon Metropolis, Bruno Bernard, during a presentation of the project.

Designed by Austrian architectural firm Baumschlager Eberle, the six-storey building, currently under construction, will be able to maintain an indoor temperature of between 22 and 26 degrees all year round "without the use of a conventional heating and air conditioning system", promises the developer Nexity, which is carrying out the project.

In the cold season, the rooms are heated by "the body heat of the occupants and that given off by lighting and household appliances, for example," architect Mathias Bernhardt of the Baumschlager Eberle firm assured AFP.

When it is warmer, cooling is done by natural ventilation with a shutter controlled by software which measures the temperature, humidity and air quality in the building via a network of sensors.

Finally, its walls made of "60 cm thick honeycomb bricks" and its "triple glazed" windows 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 within the framework of a real solidarity lease (BRS).

A second building of this type is planned for 2028 in La Garenne-Colombes (Hauts-de-Seine).