Tacit Planning Permission: When the Administration Turns a Blind Eye, the Courts Reopen the Files

Imagine you own a villa in Mandelieu-la-Napoule, overlooking the bay. You decide to add a conservatory without applying for planning permission, convinced that no one will notice this small extension. Months go by, the administration says nothing. You tell yourself everything is fine, that silence equals acceptance. But then a neighbour complains about the nuisance - the shadow cast on their swimming pool, the obstructed view. They file a complaint. What happens then?

I encounter this situation regularly in my practice, whether on the Côte d'Azur or in the Landes. Property owners think that the lack of reaction from the town hall amounts to tacit authorisation. They build, renovate, transform, then find themselves before the criminal court for the offence of building without planning permission. The question is simple: if the administration eventually grants tacit planning permission (i.e., permission obtained through the administration's silence after a certain period), does this erase the offence committed?

The Court of Cassation, in a fundamental judgment from 1997, answers clearly: no. Tacit planning permission obtained after the fact does not make the already consummated offence disappear. In short, you cannot use the administration's silence as a blank cheque to build illegally, then hope to be whitewashed afterwards. This decision, over twenty-five years old, remains highly relevant, especially in our Grasse jurisdiction where property pressure is strong and the temptation to build without authorisation is common.

The facts: a story that happens every day

Let's take the case that led to this decision. We are in the 1990s, somewhere in France - but let's transpose it to Antibes, to better understand. Mr Durand, owner of a plot on the outskirts of the city, decides to install a clay pigeon shooting range (a shooting stand). He does not apply for planning permission, perhaps thinking it is a light installation, or that he will obtain consent afterwards. The shooting range becomes operational. Gunshots resound regularly.

A few hundred metres away is the Château du Rouvre - let's call it rather a beautiful Antibes property, with its gardens, its tranquillity. The owners, Mr and Mrs Martin, struggle with these noise nuisances. They take legal action, not only to stop the disturbance but also to obtain compensation for the harm suffered. They attack Mr Durand on two fronts: on one hand, for the nuisances (what is known in law as an abnormal neighbourhood disturbance), on the other hand, for building without planning permission - a criminal offence.

The judicial journey is instructive. At first instance, the judges recognise the disturbance and convict Mr Durand. But he appeals. Meanwhile, what happens? The administration, through its silence, has granted tacit planning permission for the shooting range. Mr Durand then believes he is safe: how could he be convicted for building without planning permission, when permission now exists, even if tacit? The case goes up to the Court of Cassation, which will decide this crucial question.

The court's reasoning — dissected

The magistrates of the Court of Cassation reason with implacable logic. They first recall a fundamental principle of criminal law: the offence is consummated at the moment the illegal act is committed. Here, the offence of building without planning permission is realised as soon as the works are undertaken without the required authorisation. This offence is instantaneous: it does not last over time, it is accomplished once and for all.

Next, the judges analyse the nature of tacit planning permission. What is tacit planning permission? It is a legal fiction: if the administration does not respond to a planning application within a determined period (generally two months, four months if the project is complex), silence equals acceptance. But beware: this fiction only works if an application has been submitted! In our case, Mr Durand did not apply for anything. The tacit planning permission he claims therefore does not exist as such - or rather, if it exists, it is obtained a posteriori, through procedural manoeuvring.

The Court then establishes the key principle: "The obtaining of tacit planning permission, regarding constructions erected without the required planning permission having been sought or obtained beforehand, cannot have the effect of making the previously consummated offence disappear." In other words, even if the administration, through negligence or tolerance, eventually grants tacit planning permission, this does not whitewash the past. The offence remains punishable.

The judges base their decision on Article L. 480-4 of the French Planning Code (which punishes building without planning permission) and on the general principles of criminal law. They reject Mr Durand's argument, which consisted of saying: "Since I have planning permission now, I could not have committed an offence." The Court responds: if you had submitted an application before building, and if the administration had remained silent, you could have benefited from tacit planning permission without committing an offence. But building first, then invoking tacit planning permission obtained after the fact, is putting the cart before the horse. This reasoning applies perfectly to the situations I encounter in Mandelieu, where some property owners add floors or enlarge their seafront villas without authorisation, thinking they will regularise later.

What this changes for you — concretely

But what exactly does this change for you, property owner, tenant, or real estate professional? Let's take each profile.

If you are a landlord (the one who rents out a property): be careful with works you undertake in your property. Suppose you buy a flat in Antibes, in the old quarter, and decide to create an additional window to enjoy the sea view. Without planning permission, it is an offence. If your tenant or a neighbour files a complaint, the fact that the town hall said nothing will not protect you. Sanctions can be heavy: up to €6,000 fine per square metre built illegally, and obligation to demolish. undefined, I have encountered cases where property owners had to demolish 30 m² extensions, resulting in damages of several tens of thousands of euros.

If you are a tenant: be wary of properties with suspicious modifications. A garage converted into a studio, a covered terrace without authorisation... If you sign a lease for such a property, you risk having to leave if the construction is illegal. Worse: you could be considered an accomplice if you participated in the works. Always check that habitable parts comply with the planning permission.

If you are a purchaser (in the process of buying): this decision reinforces the importance of legal due diligence. Before buying a villa in Mandelieu with a swimming pool or pool-house, ensure these facilities are legal. Tacit planning permission invoked by the seller guarantees nothing. If works were done without planning permission, you are buying a property burdened with an offence, and you could be prosecuted after acquisition. I have seen purchasers discover, after signing, that a magnificent conservatory had to be demolished - a straight loss of €20,000 to €50,000.

If you are a co-owner: works on common parts (roof-terrace, façade, lift) often require planning permission. If your managing agent carries out works without authorisation, the entire co-ownership can be liable. The Court of Cassation's decision means that even if the town hall regularises afterwards, co-owners who voted for the works could be prosecuted criminally.

In summary: tacit planning permission is not an all-risk insurance. It only protects if the application was made before the works. Afterwards, it is too late.

Four tips to avoid this type of dispute

• Always submit a planning application before starting works, even for a small modification. In Mandelieu, for a fence over 2 metres or a swimming pool over 10 m², planning permission is required. Never presume the administration's silence.
• Keep all evidence of submission: town hall receipt, acknowledgement of receipt, copies of plans. In case of dispute, you can prove you acted in accordance with the rules.
• Check the compliance of properties you rent or buy. Ask to see the original planning permission and any modifications. A notary or specialised solicitor can help you.
• In co-ownership, require the managing agent to obtain necessary authorisations before any vote in general meeting. An estimate without planning permission is a dangerous estimate.

Deepening: related case law and developments

The 1997 decision fits into consistent case law. Already in 1986, the Court of Cassation had ruled that tacit planning permission did not regularise illegal constructions retroactively (Cass. crim., 4 November 1986). It confirmed this position several times, for example in 2005 (Cass. crim., 8 November 2005).

What few people know is that this case law was reinforced by the ALUR law of 2014, which toughened sanctions for building without planning permission. Now, mayors can order demolition without going through a court judgment, if the works are manifestly illegal. In our Grasse jurisdiction, planning services are increasingly vigilant, notably in Antibes where architectural heritage is protected.

The trend of the courts is clear: they refuse to whitewash constructions done in full knowledge. Even the good faith of the builder ("I thought it was authorised") is rarely accepted as an excuse. Only the existence of a prior application can justify benefiting from tacit planning permission.

In practice: what to do

Here is a checklist to guide you:

1. Before building: consult the PLU (Local Planning Scheme) of your municipality. In Mandelieu, certain areas are protected (proximity to the natural park, seafront). Submit a planning application if necessary.
2. During works: display the planning permission on the site. Keep a works diary with photos, in case a neighbour disputes compliance.
3. If you discover an illegal construction on your property (bought or rented): regularise as soon as possible. A prior declaration or retroactive planning permission can limit sanctions, but will not erase the past offence.
4. In case of proceedings: do not rely on tacit planning permission as a defence. Consult a specialised solicitor to negotiate with the town hall or public prosecutor's office.

Do you find yourself in a similar situation? A first 30-minute consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →