Entitled "Together for a low-tech urban transition", a manifesto published last June collected new signatures during the International Market for Real Estate Professionals (Mipim).
Its supporters intend to "do better with less" and create "a credible alternative to the race for particularly energy-intensive technological innovation".
The promoter Nexity, which joined the first promoters of the approach, Groupama Immobilier, BNP Paribas Real Estate or SNCF Immobilier, claims "real estate that is sustainable, made to last, frugal, and where technology has a measurable use", explains to AFP Jean-Claude Bassien, deputy managing director.
"There was a great moment of fantasy because everything was technology, digital, where you could think that everything would be + driven + by data, that the city of the future would be a city where users would be a sum of digital data. That fantasy kind of evaporated," he says.
The technological devices of the "smart city", continues Mr. Bassien, were too little connected to each other to be effective, considered too intrusive by the citizens... and cost the builders unnecessarily expensive.
In a difficult context for new real estate, introducing less superfluous technology therefore makes it possible to lower costs.
"Real estate has somewhat fallen into the same trappings as the automotive industry: we have very sophisticated vehicles, very fragile in maintenance, of which we barely use 30% of the functionalities", also judges Eric Donnet, CEO of Groupama Immobilier, specialist in office real estate.
"Today you enter a building, the doors are automatic; you enter a room, the lights come on; there are several of you, the ventilation is activated; the TV screen, which is necessarily giant, is pre- lit...", he mocks.
To reduce the energy consumption of its buildings, the group intends to reduce, or even eliminate, the need for heating and air conditioning.
"Yes, above 26 degrees, it's a little hot. But if it's 12 days a year, it's not dramatic", decided the deputy general manager, Astrid Weill.
Buildings that can be dismantled, adding floors using wood, construction on railway wasteland... SNCF Immobilier also wants to be a pioneer in sober construction.
“We are saving materials, materials and land, we are aiming for high levels of certification in the renovation, in the residential and industrial sectors”, explains the president of the group, Katayoune Panahi.
However, there is no question of rejecting the technology as a whole, they all recall.
"Low-tech will require energy, but wisely. Not useless... no gadgets", says Méka Brunel, president of the University of the city of tomorrow, a think tank around the lower city. -carbon.
"Regenerated" and "reversible"
Elected officials are also moving towards more economical construction. At Mipim, the metropolis of Lyon, led by the ecologist Bruno Bernard, praised its project to rehabilitate the Part-Dieu business district, avoiding as much as possible the demolition and reconstruction of buildings, operations that emit a lot of CO2.
"Five or six years ago, we didn't even ask ourselves any questions: we were demolishing, we were rebuilding. The question of regenerating a building didn't even arise," he explains.
If the site costs more, the additional cost will be compensated over time, he says. "Whatever happens, the cost of energy will increase over time. Constructing isolated buildings is a matter of course!" he adds.
“Ten years ago, when we talked about the +smart city+, we were talking more about complete automation of air conditioning systems, etc. Today, we are going to talk about natural ventilation, exposure, angle of the building...", also says Jean-Philippe Dugoin-Clément, vice-president (UDI) of the regional council of Ile-de-France in charge of town planning. In its next urban planning scheme, the region will thus ask developers to think about the reversibility of buildings, that is to say their ability to change use: from offices to housing, or the reverse.
"We will try to support, encourage and sometimes force to have a much more sober or resilient constructive typology", he promises.