Expropriation: When the Increase in Value of Your Land Can Reduce Your Compensation

Imagine you own a 5,000 m² plot of land in Dax, near the bullring. The town hall decides to expropriate a 500 m² strip to widen a road. You think: "I'm going to receive compensation for this lost land." But did you know that this expropriation could increase the value of your remaining 4,500 m²? And that this increase could reduce your compensation?

This is exactly the question thousands of landowners ask themselves every year. When the administration takes part of your land, it often changes the environment: new road, public facilities, improved access. These changes can enhance the value of what you have left. But how does this affect the compensation you receive?

A decision by the Court of Cassation (the highest judicial court in France) of 30 May 1973 provides a clear answer, and it directly concerns landowners in the jurisdiction of Mont-de-Marsan, from Dax to Saint-Paul-lès-Dax. This decision requires judges to systematically assess this increase in value and offset it against the compensation. Let's see what this means for you.

The facts: a story that happens every day

Mr Dupont, owner of a large 10-hectare agricultural plot near Saint-Paul-lès-Dax, sees his property crossed by a motorway project. The State decides to expropriate 2 hectares for the construction of the carriageway. Mr Dupont expects significant compensation for these 20,000 m² lost.

But here's the thing: the expropriating authority (the administration taking the land) claims that the remaining 8 hectares will increase in value. Why? Because the motorway will open up the area, provide quick access to Dax, and potentially pave the way for future development. The administration therefore argues that Mr Dupont is not only suffering a loss but also gaining from what remains.

At first instance (before the tribunal), Mr Dupont obtains compensation based solely on the value of the 2 hectares expropriated. The expropriating authority appeals, and that's where things get complicated. The Court of Appeal must decide: should it take into account this famous increase in value, even if the expropriating authority didn't really raise it at the tribunal?

undefined, I have come across cases where landowners in the Landes found their compensation reduced by 30% due to this offset. One case in Mont-de-Marsan involved a plot whose residual value increased after the creation of a business park nearby.

The court's reasoning — broken down

The Court of Cassation, in its judgment of 30 May 1973, establishes a fundamental principle: the Court of Appeal that fixes expropriation compensation is required to rule on the expropriating authority's claim seeking to declare an increase in the value of the remaining parts of the expropriated plots, even though it was not raised at first instance. In other words, even if the administration didn't raise this point before the tribunal, it can do so on appeal, and the judges must examine it.

The legal basis? Article L. 322-5 of the Expropriation Code (which governs compensation in case of land acquisition by the administration). This article provides that compensation must cover direct, material, and certain loss. But it also specifies that if the expropriation creates an increase in value for the remaining land, this increase must be deducted. In short, you cannot be compensated for a loss while benefiting from a gain created by the same operation.

The judges on the merits (those of the Court of Appeal) must therefore: 1) assess the residual increase in value (the increase in value of the non-expropriated land), 2) assess the depreciation (the loss of value due to the expropriation), and 3) carry out the necessary offset. However, be careful: they must do so by a separate provision, i.e., by clearly explaining their calculation.

What few people know is that this decision confirms earlier case law. It is not a revolution, but it reinforces the obligation for judges to systematically examine this aspect. The parties' arguments? The expropriating authority says: "Mr Dupont will gain in value, so his compensation must be reduced." Mr Dupont retorts: "This increase in value is hypothetical, and you haven't proven it at the tribunal." The Court rules: proof can be provided on appeal, and judges must quantify it precisely.

What this changes for you — concretely

But what exactly does this change for you, as a landowner, tenant, or real estate professional? Let's take concrete examples.

If you are a landlord (you lease land or a building): imagine you own a warehouse in Dax, and part of it is expropriated for a tram project. The compensation for the lost area could be reduced if the tram increases the attractiveness of your remaining property. undefined, a client saw his compensation drop by €15,000 because his remaining offices were better served.

If you are a tenant: you are not directly affected by the compensation, but if your landlord receives less, they might be less inclined to invest in the property. Or conversely, if the increase in value is significant, they might want to increase the rent in the long term.

If you are a purchaser: before buying land, check if it is affected by an expropriation project. In Saint-Paul-lès-Dax, a plot bought for €200,000 saw its residual value increase by €50,000 after partial expropriation, but the lost compensation was €80,000. The landowner therefore suffered a net loss.

Realistic numerical example: 1,000 m² plot in Mont-de-Marsan, initial value €100/m². Expropriation of 200 m². Expected compensation: 200 m² × €100 = €20,000. But if the remaining 800 m² gain €20/m² in increased value (thanks to a new road), gain: 800 × €20 = €16,000. Final compensation after offset: €20,000 - €16,000 = only €4,000. How to react? You need to anticipate this offset in your negotiations.

Four tips to avoid this type of dispute

• Have your property assessed by an independent expert before any proceedings: a surveyor-expert or notary can estimate the current value and potential increase in value. In Dax, this costs around €1,000 to €2,000, but it can save you thousands of euros in loss.
• Keep all documents relating to your property: cadastral plans, deeds of sale, photos, market studies. They will serve as evidence in case of dispute over value.
• Negotiate with the expropriating authority as soon as the project is announced: don't wait for the judgment. Propose an estimate of the increase in value and discuss it. In the jurisdiction of Mont-de-Marsan, administrations are often open to discussion if you have solid arguments.
• Consult a lawyer specialising in expropriation law as soon as the first letters arrive: early consultation can help you structure your defence and anticipate the offset. Avoid embarking on a complex procedure alone.

Deep dive: related case law and developments

This 1973 decision is part of a consistent line of case law. Before it, a 1965 Court of Cassation judgment (No. 64-10.045) had already established the principle of offset between increase in value and compensation. But the 1973 judgment goes further by requiring judges to rule even if the issue was not raised at first instance.

A more recent decision, by the Bordeaux Court of Appeal in 2018 (which covers the jurisdiction of Mont-de-Marsan), applied this principle to a case where expropriation for a high-voltage line increased the value of the remaining agricultural land thanks to better access. The judges reduced the compensation by 25% after offset.

The trend in the courts is clear: they strictly apply the offset principle. What does this mean for the future? Landowners must be increasingly vigilant. With growing urbanisation in the Landes, infrastructure projects (roads, networks, facilities) are multiplying, and with them the risks of offset.

Frequently asked questions

Q: Is the increase in value always deducted from the compensation?
A: Yes, if it is proven and certain. But if the increase in value is less than the depreciation, you still receive compensation, reduced by the amount of the increase.

Q: How to prove or challenge an increase in value?
A: Through a contradictory expert report (an expert appointed by both parties) or through comparable sales in the area. In Saint-Paul-lès-Dax, prices of land near the lake or thermal baths are often used as a reference.

Q: Does this rule also apply to tenants?
A: No, not directly. But a tenant could be indirectly affected if the landlord suffers a loss.

Q: What to do if I disagree with the assessment of the increase in value?
A: Appeal the decision within the time limits (generally 2 months) and present your own evidence (expert reports, testimonies).

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 →