Dangerous Trees: When Risk Alone is Sufficient to Condemn the Neighbouring Owner

Imagine yourself in Saint-Paul-lès-Dax, in your garden in the Landes region. You admire your century-old oak trees, but your neighbour confronts you: "Your trees are leaning dangerously towards my house!" What should you do? Wait for a storm to make them fall? Or act immediately?

This question is asked by hundreds of owners each year in the jurisdiction of Mont-de-Marsan. Between the maritime pines of Tarnos and the cork oaks of Chalosse, vegetation is omnipresent... and sometimes problematic. But when does a tree become a legal threat, and not just an aesthetic nuisance?

The Court of Cassation answered clearly in 2014: risk alone, even before any damage, can constitute an abnormal neighbourhood disturbance (a prejudice exceeding the normal inconveniences of social life). A decision that changes the game for all holders of wooded land.

The Facts: A Story as Common as Any Day

Mr. Dupont, owner of a house in Saint-Paul-lès-Dax, owned several large poplar trees on the boundary of his property. These trees, about thirty years old, leaned clearly towards the neighbouring house of Mr. Martin. The roots were already lifting the boundary wall, and during gusts of wind, the branches dangerously brushed against the roof.

Mr. Martin had alerted his neighbour several times: "Your trees threaten my safety!" But Mr. Dupont invariably replied: "Let's wait for them to fall, we'll see. Anyway, if they fall during a storm, it will be a case of force majeure (an unforeseeable and irresistible event)."

The matter took a judicial turn after a particularly violent storm in 2011. Two poplars did indeed fall onto Mr. Martin's property, causing damage estimated at €15,000. Mr. Martin sued his neighbour, not only for repair of the damage, but also for the abnormal neighbourhood disturbance he had suffered for years.

The Tribunal de Grande Instance of Mont-de-Marsan initially ruled in favour of Mr. Dupont on this point: according to the first judges, mere risk did not constitute an established disturbance. But the Court of Appeal of Pau overturned this judgment, considering that the permanent danger did indeed create an abnormal disturbance. Mr. Dupont then lodged an appeal to the Court of Cassation... which was dismissed.

The Court's Reasoning — Analysed

The Court of Cassation confirmed the appeal court's ruling with a two-step reasoning. First, the judges recalled that Article 1240 of the Civil Code (which obliges repair of damage caused by one's fault) applies to neighbourhood disturbances. But be careful: here, fault is not necessarily active negligence. The mere fact of allowing a danger to persist may suffice.

Then, and this is the crucial point, the high court considered that a certain and imminent risk constitutes in itself an abnormal neighbourhood disturbance. In other words, it is not necessary to wait for the damage to occur. undefined, I have encountered cases where owners waited for the actual fall of trees to act, thinking this would strengthen their case. This decision shows that this is a strategic error.

The judges' reasoning relies on an evolution in case law. Before this decision, some courts required proof of actual damage. Now, the threat is sufficient. What few people know: this approach also protects the owner of the risk, as it avoids more significant damage in case of a fall.

Mr. Dupont had pleaded force majeure due to the storm. But the Court rejected this argument: if the trees were already in a dangerous state before the storm, this meteorological event does not constitute an exonerating cause. In short, the storm is only a revealer of the pre-existing danger, not its sole cause.

What This Changes for You — Practically

If you are a landlord (who rents out their property) in the jurisdiction of Mont-de-Marsan, you must regularly monitor the trees on your property. A tenant can alert you to a danger, and your liability will be engaged even if the tree has not yet fallen. undefined, I have seen cases where absent owners had to compensate their tenants for permanent anxiety due to threatening trees.

For tenants, this decision is an additional weapon. You are no longer obliged to wait for a tree to fall on your vehicle or home to act. A formal demand (a formal letter requiring action) addressed to the owner can be justified as soon as the danger is identified. In Tarnos, where sea winds are frequent, this vigilance is particularly crucial.

Purchasers must now integrate this risk into their surveys. A tree leaning over the desired property is no longer just an aesthetic or maintenance problem, but a potential source of legal proceedings. I systematically advise my clients to require an arboricultural survey before purchase, especially for wooded properties in the Landes.

As for co-owners, the question arises differently. If dangerous trees are on common parts, it is the managing agent who must act. But be careful: decision-making delays in general meetings can be long. In this case, a threatened co-owner can act through an urgent procedure to order safety works.

Four Tips to Avoid This Type of Dispute

• Have your trees surveyed every 3 to 5 years by a certified professional. A €200-400 survey can avoid thousands of euros in damages.
• Document your exchanges with the neighbour from the first alert. A registered letter with acknowledgment of receipt is better than a garden conversation.
• Take preventive action on at-risk trees: pruning, cabling (cable system to stabilise), or felling if necessary. In Saint-Paul-lès-Dax, certain species like poplars require particular attention.
• Check your insurance: some exclude damage caused by poorly maintained trees. An extended civil liability clause is recommended.

Further Analysis: Related Case Law and Developments

This decision fits into a broader jurisprudential trend of preventive protection. Already in 2006, the Court of Cassation (ruling No. 05-10.305) had considered that a dangerous excavation on a property boundary constituted an abnormal disturbance before any collapse. But what exactly does this change for trees?

The specificity of the 2014 ruling lies in its confrontation with the force majeure argument. By rejecting this argument, the judges strengthened the objective liability (without proven fault) of the owner. A more recent decision (Civ. 3rd, 5 July 2018, No. 17-19.061) confirmed this orientation by condemning an owner whose bamboo was invading the neighbouring property, creating a risk for the foundations.

For the future, this case law means that courts will be increasingly demanding on prevention. Owners will have to anticipate risks, not just react to damage. In the jurisdiction of Mont-de-Marsan, where storms are frequent, this vigilance is all the more crucial.

Key Points to Remember

• Risk alone is sufficient: a tree leaning dangerously constitutes an abnormal neighbourhood disturbance, even before it falls.
• The storm does not exonerate: if the tree was already dangerous, the meteorological event is not a cause of force majeure.
• Act quickly: from the first alert, have a survey done and document everything.
• Indicative costs: an arboricultural survey (€200-400), pruning (€300-800 per tree), but potential damages of €5,000 to €50,000 depending on the case.
• Time limits: legal action must generally be brought within 5 years of knowledge of the disturbance.

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 →