At the beginning of the summer, two blows were successively brought to this principle, which aims to reduce the rate of nibbling of natural spaces by the city to reach zero in 2050.
The first by the Association of Mayors of France (AMF), which announced to seize the Council of State against two of the three decrees of application of the ZAN.
The second by senators, who swept in a report its application by the government, ensuring that "the economic model of ZAN remains to be defined".
Artificialization degrades biodiversity, increases the risk of flooding and contributes to global warming by releasing CO2 stored in the soil.
In ten years, its rate has decreased by almost a third, from 31.589 hectares in 2009-2010 to 22.553 in 2018-2019, according to the Observatory of soil artificialization.
But it remains too high: according to the objectives set by the Climate and Resilience Law of 2021, it will still have to be halved every ten years to reach net zero in 2050.
What directs, for a long time, professionals of the construction, skeptical on this measurement which threatens whole sections of their activity.
"Counter productive"
For the French Building Federation (FFB), the ZAN risks "accelerating the land shortage" and further increasing real estate prices. "It will have a double negative effect, on the price and on the quality of life", also believes François Rieussec, president of the National Union of Developers.
The Federation of Real Estate Developers (FPI), which holds its annual congress in Strasbourg where the subject of "land sobriety" has been debated, is not opposed to it in principle, but stresses that the first priority is to produce housing .
And now, it is elected officials, mostly on the right, who are leading the revolt.
"The government did not at all plan the rest of the story. It went very quickly on this subject (...) but it did not plan its financing", supports the senator (LR) of Vaucluse Jean -Baptiste Blanc, special rapporteur of a text on ZAN.
He recommends, among other things, to establish a “ZAN fund” to finance the efforts of the communities or to direct budgetary and tax aid towards land sobriety.
He also fears that this will accentuate the territorial imbalances, between the metropolises which would have the capacity to develop innovative solutions and the small communities, which are more deprived.
On the side of the mayors, the AMF castigated in a press release "a rigid recentralisation approach" and implementing decrees which "accentuate territorial fractures by opposing projects to each other, and are counterproductive because their arithmetic and undifferentiated application goes against the virtuous developments in the fight against climate change, but also the developments essential to the ambition of reindustrialization of the country".
Wastelands
"How does a municipality that has worked for the past ten years on its wasteland do?", Also wonders Constance de Pélichy, mayor (LR) of La Ferté Saint-Aubin (Loiret), who demands that the State take into account the past efforts of the municipalities in terms of land sobriety.
Why this objection?
"It's normal, because the software that has been given to elected officials for a long time is construction on the void", reacts to AFP Christine Leconte, president of the National Council of the Order of Architects.
"Where the State must move forward with the territories is by allowing them to see their potential, which today is not agricultural land but wasteland, small plots, hollow teeth, buildings in ruins “, she adds.
"The main hypothesis is that a certain number of elected officials had not been made aware of the problem, and did not see this measure coming", judge Vincent Le Rouzic, urban planner and deputy director of studies at the Factory de la Cité, the Vinci group's laboratory of ideas.
"The second element is that we have certain territories which have a mode of territorial development mainly based on progressive urban sprawl, by diffuse flags, and from this point of view, the ZAN objective is an obstacle," he said.
Precisely this model that the law intends to limit.