A NÖMA habitat is designed, manufactured in our workshop, then delivered and installed on your land by our teams. But before the habitat ever arrives on site, one question comes up systematically: which administrative steps need to be taken, and whose responsibility are they? This article gives the general principle and points to the competent authorities: it does not replace your town hall's own ruling, and it is not legal advice.
Understanding the topic
As our Regulations & installation page already states, and as we detail in “Turnkey modular home: what's included” (section “What to know before you start”), the habitat itself and the land are two separate scopes. Every plot is different, every municipality applies its own rules, and it is this second scope that this article details.
Under French planning law, a new construction falls, depending on the case, under no formality at all, a simple prior declaration of works (déclaration préalable), or full planning permission (permis de construire). What determines the applicable regime is not whether a habitat is modular or built on site: it is the floor area created (surface de plancher or emprise au sol) and, for non-permanent installations, their duration. Service-Public.gouv.fr, the official portal of the French administration, devotes its factsheet “Déclarer préalablement des travaux” (reference F17578, updated and verified on 19 October 2026) to this exact question: it confirms that a prior declaration is required for works that create floor area or ground coverage without falling under full planning permission, and it points to articles R. 421-9 to R. 421-12 of the Code de l'urbanisme for new constructions, and to article R. 421-17 for works on an existing building. The regime for temporary constructions (article R. 421-5 of the same code) is also referenced, though the factsheet itself does not detail its conditions; a point worth confirming directly with the local planning department for any non-permanent installation.
Deep exploration
This official factsheet does not publish, in its directly readable text, the surface thresholds expressed in square metres. The planning departments of several French local authorities we consulted nonetheless place these thresholds, for a new construction, at around 5 m² and 20 m² of floor area or ground coverage, below and up to which no formality or a simple prior declaration applies, noting that a different threshold (up to 40 m²) can apply in certain situations involving an extension of an existing building in an urban zone covered by a local urban plan (PLU). These figures are not drawn from the national Service-Public.gouv.fr factsheet itself: they come from local planning authorities, converge with one another, but can vary according to each municipality's own PLU. Only your town hall's planning department confirms the threshold that actually applies to your project.
The local urban plan (PLU) of the municipality is the document that, in practice, decides what is possible on a given plot: zoning, height or siting rules, and protected sectors where stricter rules may apply. Two nearby plots, sitting in two different zones, can therefore fall under different regimes for the very same project. This is why, beyond the general regulation, the feasibility of a NÖMA project also depends on the plot's accessibility for transport and installation, and on the regulation applicable to the size of the project: this is exactly what our site assessment checks before any manufacturing begins, a step we recommend requesting early, alongside the checks made with your town hall, not after.
Practical guidance
One point stays constant whichever model you choose from our catalogue: the administrative steps (prior declaration or planning permission depending on surface area) remain the buyer's responsibility. NÖMA designs, manufactures in our workshop, transports and installs your habitat on your land; filing the planning file with the town hall, however, is not a service performed by NÖMA, exactly like the land itself or the connections to public utility networks (water, electricity), which need to be arranged with a local professional, coordinated with our team for the delivery schedule. This split follows the same logic detailed in “Turnkey modular home: what's included”: “turnkey” describes the completion level of the habitat itself, not responsibility for the land and its administrative steps. Before committing, a few points are worth clarifying directly with your municipality's planning department: which formality actually applies to your project given the exact surface area and your PLU's zoning, whether your plot sits in a sector subject to special rules (protected area, vicinity of a listed historic monument, a subdivision with its own rules), how long the document obtained stays valid (a prior declaration, for instance, is valid for three years and lapses if work has not started within that period, or if it is interrupted for more than one year), and the specific case of a non-permanent installation, for which a distinct regime can apply (article R. 421-5 of the Code de l'urbanisme), to be confirmed case by case.
There is no single regime that applies to “a modular home”: everything depends on the project's surface area, how long it will be installed for if relevant, and your municipality's PLU. NÖMA takes care of the design, manufacturing, transport and installation of your habitat; the administrative steps, the land and its utility connections remain on your side, in coordination with your town hall and the relevant local professionals. Our Regulations & installation page covers these questions as short answers, and our team remains available for any question about your plot's feasibility, without ever standing in for your town hall's own ruling.
Architectural perspective
At NÖMA, we see planning regulation not as a secondary administrative detail but as a genuine feasibility condition, on the same footing as a plot's accessibility. That is why our site assessment also looks at this question upstream of manufacturing, rather than leaving that check until delivery.
