Illicit Construction in the Forest: The ONF Can Demolish Without a Court Decision

Imagine: you buy a plot of land in Tournefeuille, a beautiful plot on the edge of woodland. You build a shed, perhaps even a small house. A few years later, the National Forests Office (ONF) arrives, draws up a formal report and demolishes your construction without waiting for a judge. You cry foul – an illegal act by the administration. But the Court of Cassation, in a judgment of 16 December 2009, sides with the ONF. What happened? And above all, what can you do if you are in this situation?

This decision, little known to the general public, is nonetheless crucial for any owner or neighbour of a state-owned forest. It reminds us that forestry law allows the ONF to act quickly to restore the natural state of the land, without going through a court. But is this a blank cheque for the administration? Not entirely.

In this article, I will tell you the story behind this judgment, break down the judges' reasoning, and above all give you concrete keys to avoid such a disaster. Whether you are an owner, buyer or simply a neighbour, this information can save you – literally.

The Facts: A Story That Happens Every Day

The case starts modestly. An individual, Mr Y., owns a plot on the edge of a state-owned forest. For years, he has used part of the adjoining woodland, installed light constructions – a shed, a garden shelter – and considers that this strip of land belongs to him. But one day, the ONF carries out a boundary survey (official delimitation of properties) and discovers that Mr Y.'s constructions encroach on the forest domain. In other words, Mr Y. has built on land that does not belong to him.

The ONF then draws up a formal report of the offence (procès-verbal) recording the unauthorised occupation. On the basis of this report, the prefect issues an order authorising the restoration of the land to its original state. Without further formality, the ONF demolishes Mr Y.'s constructions. The latter, furious, sues the ONF for voie de fait – that is, an administrative action so illegal that it amounts to a violation of property rights.

The Court of Appeal, and then the Court of Cassation, reject his claim. For the judges, the ONF did not commit a voie de fait because it was acting within its legal powers: Article L. 173-4 of the Forestry Code (now codified elsewhere) allows it to restore the land, after a formal report and a prefectural authorisation. It does not matter that Mr Y. disputes the ownership of the disputed strip: the 1981 boundary survey, which fixed the limits, was binding.

The Reasoning of the Court — Explained

To understand this judgment, you need to grasp two key concepts: voie de fait and the powers of the ONF.

Voie de fait is the bad word of administrative law. In principle, the administration cannot take possession of private property or destroy it without being authorised by a judge, except in an emergency. If it does so anyway, it commits a voie de fait, and you can bring the matter before the civil courts (not the administrative court) to obtain compensation. But here, the Court of Cassation says: the ONF did not commit a voie de fait because it had the right to act.

What right? Article L. 173-4 of the Forestry Code (in its version then in force) provides that the ONF may, with the authorisation of the prefect and after a formal report recording the state of the land, restore it to its original state. In other words, if someone builds illegally in a state-owned forest, the ONF can demolish without going through a judge. This is an exception to the rule of protection of private property.

The judges note that in this case, two conditions were met: a formal report of the offence had been drawn up, and a prefectural order had been issued. It does not matter that Mr Y. disputes the materiality of the encroachment (i.e. the fact that his constructions were on the ONF's land). The 1981 boundary survey, unchallenged at the time, was conclusive. In short, the ONF did not act arbitrarily: it followed the procedure laid down by law.

What few people know is that this decision confirms a consistent line of case law: the forestry administration has a special police power to protect the forest domain. However, this power is not absolute. If the ONF had demolished without a formal report or prefectural order, then that would have been a voie de fait.

What This Changes for You — Concretely

If you own land adjoining a state-owned forest, this decision directly concerns you. Imagine you have doubts about the boundaries of your property. If you build beyond the boundary marker, the ONF may one day demolish your shed, your garage, even your house, and you cannot stop it by bringing an action for voie de fait. Your only remedy will be to challenge the boundary survey itself, but that is another procedure, long and costly.

Let's take a concrete example in Labège: you buy a house with a large wooded garden. To be safe, you have a fence installed along what you believe to be your boundary. But the official boundary survey, carried out 20 years earlier, shows that your fence encroaches 3 metres onto the state-owned forest. The ONF can require the fence to be moved, or even demolish it if it is considered a construction. And you cannot invoke adverse possession (prescription acquisitive) to become owner of that strip: state-owned forests are imprescriptible.

If you are a tenant of a property bordering a forest, you must be particularly careful. Before signing a lease, check the cadastral boundaries and the boundary survey. In case of encroachment, it is the owner who will be held liable, but you could lose your enjoyment.

Finally, if you are a property professional (estate agent, developer), you must ensure a boundary survey is carried out before any transaction involving land bordering a state-owned forest. An error of a few metres can lead to demolitions and costly litigation.

Four Tips to Avoid This Type of Dispute

• Have a boundary survey carried out in the presence of all parties (bornage contradictoire) before any construction or acquisition. The boundary survey is an operation that officially fixes the limits of your property in the presence of your neighbour (here, the ONF). It costs between €1,500 and €3,000, but it will save you from much more expensive demolitions.
• Do not build without checking the Local Urban Plan (PLU) and any easements. Certain areas are protected (classified woodland, etc.) and any construction is prohibited. Check with the town hall of Tournefeuille or Labège.
• Keep all documents relating to your property: deed of sale, cadastre, boundary survey, correspondence with the ONF. In case of a dispute, these documents will be essential.
• If you receive a formal report from the ONF, do not ignore it. React immediately by consulting a specialist lawyer. You can challenge the formal report, but the deadlines are very short (often 15 days).

Further Reading: Related Case Law and Developments

This judgment is part of a line of decisions that strengthen the powers of the ONF. Thus, in a judgment of 24 February 2011 (No. 10-10.698), the Court of Cassation held that the ONF could also demolish illicit constructions without waiting for a court decision, provided the occupation was manifestly irregular. The trend is therefore clear: the forestry administration has a power of direct action to protect the domain.

Conversely, some older decisions (Civ. 1re, 12 July 2005) had limited this power by requiring an emergency. But the 2009 judgment removes this condition: the prefectural authorisation and the formal report are sufficient. This means that the ONF can act even without an emergency, simply to stop an unlawful occupation. This is an important development that reduces the protection of unauthorised occupants.

For the future, it is possible that the legislature will regulate these powers more strictly, but for now, the case law remains constant. If you are faced with a similar situation, you must act quickly and not rely on a voie de fait claim to save you.

Checklist Before Acting

• I wish to build near a state-owned forest: before submitting a planning application, have a boundary survey done and verify that the land does not encroach on the domain. Check the PLU.
• I receive a formal report from the ONF for encroachment: do not demolish anything yourself. Contact a lawyer immediately. You have 15 days to challenge the formal report before the administrative court.
• The ONF has already demolished my construction without a court decision: you can claim damages if the ONF did not follow the procedure (no formal report, no prefectural order). But if the procedure was followed, you have no remedy on the merits.
• I want to buy land on the edge of a forest: require a recent boundary survey and a certificate from the ONF confirming no encroachment. Have this condition included in the preliminary sale agreement.
• I am a tenant: check that the lease mentions the exact boundaries of the rented land. If in doubt, ask the owner to provide a boundary survey.

Are you 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 →