Selling a house with unauthorised works in France

The limitation periods

Criminal law. For 6 years, the person who carried out the works faces a fine of at least €1,200, up to €6,000 per square metre of floor area built, demolished or made unusable, or €300,000 in other cases; for a repeat offence, 6 months’ imprisonment may be added (Planning Code, art. L480-4). The text targets “Carrying out works” that are irregular (our translation).

Civil law. The council can apply to the tribunal judiciaire (civil court) for an order for the demolition or bringing into compliance of a structure built without the required authorisation or in breach of it, for 10 years after completion of the works (art. L480-14). The text targets the structure, without distinguishing according to its owner. An injured third party can seek demolition, bringing into compliance or damages for 5 years (service-public.gouv.fr).

Administrative law. The council can also impose a fine of up to €30,000 and serve formal notice to regularise, with a penalty payment of up to €1,000 per day of delay, capped at €100,000 (art. L481-1).

The case of a building without a building permit

Once a building has been completed for more than 10 years, the town hall can no longer refuse a permit or object to a déclaration préalable (prior declaration) on the grounds that the original building was irregular (art. L421-9). This protection does not apply, in particular:

• “Where the building was erected without any building permit having been obtained when one was required” (5°);
• where the building exposes its users or third parties to a serious risk, where demolition proceedings have been brought, or where it is located in a national park, a listed site or on public land.

In that case, the building has no legal existence in administrative terms: for any new project, you must apply for an authorisation covering the whole building, both to regularise what exists and for the new works (service-public.gouv.fr). For an old building that can no longer be the subject of criminal or civil action, the authorities can, however, authorise the works needed to preserve it. The irregular building itself remains liable to taxe foncière (property tax).

Gap between the guidance page and the law. Service-public.gouv.fr presents the absence of any time limit as applying to any building erected “without planning authorisation”. Article L421-9 more precisely targets a building erected without a building permit when one was required. Works that only needed a simple déclaration préalable (prior declaration) remain under the 10-year regime, subject to the article’s other exceptions. It is the text of the law that applies.

Informing the buyer

The Civil Code requires a seller who knows information “whose importance is decisive” for the buyer’s consent to pass it on, provided the buyer is legitimately unaware of it or relies on the other party (art. 1112-1). Information is decisive if it has a direct and necessary link with the content of the contract. “The parties may neither limit nor exclude this duty.” Failure to comply makes the seller liable and can lead to the sale being annulled.

In practice, the seller discloses the works concerned from the preliminary contract (compromis de vente, preliminary sale contract) onwards and supplies what they have: authorisations, déclaration d’achèvement et de conformité (declaration of completion and compliance), completion date, invoices. The buyer can then negotiate the price, require regularisation before the sale or walk away in full knowledge of the facts.

Regularising before selling

Service-public.gouv.fr points out that you can apply at any time for works carried out without authorisation to be regularised. The town hall then checks their compliance with the planning rules in force and can:

1. regularise the building;
2. require certain works to bring it into compliance;
3. refuse regularisation if it is impossible under those rules.

A regularisation obtained is added to the sale file; a refusal is also information to be passed on to the buyer.

Which professional to consult

The géomètre-expert (chartered surveyor) measures the floor areas actually built and compares them with the authorisations obtained: this is the basis of a regularisation file. The notaire (notary) searches for planning authorisations and drafts the seller’s declarations in the preliminary contract and the deed. The agent immobilier (estate agent) factors the property’s administrative situation into the price estimate.