Reference Date in Expropriation: When a PLU Modification Does Not Count

Imagine: you own a plot of land in Saint-Max, on the outskirts of Nancy. One day, you receive a letter from the municipality informing you that your plot is included in a deferred development zone. Your land is going to be expropriated for a public utility project. The burning question on your lips: how much will I receive?

The expropriation compensation depends on the market value of the property at a specific date, called the reference date. In principle, this date is the date of the most recent act making public, approving, revising or modifying the Local Urban Plan (PLU) that delimits the zone where the property is located. But what happens if, in the meantime, the PLU is modified without changing the characteristics of the zone?

In a judgment of 13 June 2019 (No. 18-18.445), the French Supreme Court ruled: a modification of the PLU which only concerns the perimeter of the zone, without affecting its characteristics, cannot be used to set the reference date. Explanations.

The Facts: A Story Like Many Others

Mr X, owner of a plot in Saint-Max, sees his land included in a deferred development zone by a resolution of the municipal council on 28 September 2016, made public on 18 October 2016. This resolution modifies the PLU by extending the perimeter of the zone concerned, but without changing the building regulations or permitted uses. Shortly after, the expropriation procedure is initiated.

The expropriation judge must set the compensation. To do this, he determines the reference date: according to Article L. 213-4 of the French Urban Planning Code, it is the date of the most recent of the acts making public, approving, revising or modifying the PLU and delimiting the zone in which the property is located. The expropriated party (Mr X) argues that the reference date should be that of the PLU modification of 18 October 2016, because it is the most recent act. The expropriating authority (the municipality) argues that this modification did not change the characteristics of the zone and that the earlier reference date should be retained.

The judicial court rules in favour of the municipality: the modification of the perimeter without changing the characteristics of the zone does not constitute a modification within the meaning of Article L. 213-4. Mr X appeals to the French Supreme Court.

The Reasoning of the Court — Analysed

The French Supreme Court dismisses the appeal and upholds the decision of the lower courts. Its reasoning is based on Article L. 213-4 of the French Urban Planning Code, which provides that the reference date is "the date of the most recent of the acts making public, approving, revising or modifying the Local Urban Plan". But the Court specifies that this act must have "affected the characteristics of the zone" in which the expropriated property is located. In other words, a simple modification of the perimeter, without impact on the applicable planning rules (density, height, use, etc.), cannot serve as a new reference date.

The judges consider that the resolution of 28 September 2016 did not modify the characteristics of the zone: it merely extended its perimeter. Consequently, the reference date remains that of the earlier act that defined the characteristics of the zone. However, note: if the modification had changed the building regulations or uses, it could have been retained.

This reasoning is consistent with established case law: the reference date must be the one that sets the planning regime applicable to the property, not the date of any administrative modification. Thus, the French Supreme Court confirms a position already adopted in earlier judgments (Civ. 3e, 12 July 2018, No. 17-21.345).

What This Means for You — Practically

For a landowner in Laxou or elsewhere, this decision has direct implications on the amount of expropriation compensation. Indeed, the reference date determines the value of the property: if a PLU modification occurring just before the expropriation had increased buildability (e.g., change from agricultural to building land), the land value would have risen. But if the modification only changes the perimeter, the value remains that of the earlier date.

Practically, for Mr X, this means his land will be valued at an earlier date, probably at a lower value. If you are in this situation, you must check whether the PLU modification actually changed the characteristics of your zone. undefined, I have encountered cases where municipalities tried to "freeze" the reference date by modifying the PLU without changing its substance. Owners must be vigilant.

For a potential buyer, note that the reference date also influences the right of pre-emption: if the property is in a deferred development zone, the municipality can pre-empt at a price based on this date. So it is better to know the reference date before buying land in a sensitive area.

Four Tips to Avoid This Type of Dispute

• Keep all successive PLUs: since the last revision or modification affecting the characteristics of your zone, keep a record. In case of expropriation, you can challenge the date used.
• Have the modification analysed by a lawyer: if the PLU is modified, ask a professional whether this modification changes the characteristics of your zone. A simple extension of the perimeter has no effect on the reference date.
• Anticipate expropriation procedures: if you know your land is in a deferred development zone, prepare for a possible expropriation. The reference date will be that of the PLU in force at the time of the act creating the zone, unless subsequent modification of characteristics.
• Negotiate with the municipality: if the reference date is unfavourable to you, you can try to negotiate a higher compensation by demonstrating that the actual value of the property is higher than that used. But in court, the reference date is a key element.

Further Reading: Related Case Law and Developments

The French Supreme Court had already ruled on similar cases. In a judgment of 12 July 2018 (No. 17-21.345), it held that a modification of the PLU changing only the graphic regulations (map) without modifying the written regulations did not constitute a modification within the meaning of Article L. 213-4. The trend is therefore clear: only modifications affecting the substantive planning regime are taken into account.

Conversely, in a judgment of 14 November 2019 (No. 18-22.456), the Court held that a modification that increased the floor area ratio (COS) of a zone constituted a modification of characteristics, allowing a new reference date to be set. The line is therefore fine, and each case must be examined in light of the changes made.

For the future, the reform of the French Urban Planning Code (Ordinance No. 2015-1174) has unified procedures, but case law continues to refine the concept of "modification affecting characteristics". Owners must therefore follow local PLU developments.

Summary and Next Steps

Here is a FAQ to help you:

Q: What is the reference date for my land in Laxou?
A: It is the date of the last act that modified the characteristics of the zone (buildability, use, etc.). If the PLU was simply modified to extend the perimeter, this modification does not count.

Q: Can I challenge the reference date used by the judge?
A: Yes, by showing that a subsequent modification did affect the characteristics of the zone. You must provide proof of this modification (resolution, amended regulations).

Q: What is the time limit to act?
A: The appeal against the expropriation order is two months from its notification. To challenge the compensation, you have two months after notification of the expropriating authority's offer.

Q: What is the cost of a procedure?
A: Lawyers' fees vary, but a 30-minute consultation with Maître Zakine is €45. A full procedure can cost between €1,500 and €5,000 depending on complexity.

Q: What should I do if I am in the process of expropriation?
A: Contact a specialised lawyer immediately to check the reference date. If it is wrong, you can request a revision of the compensation.

Are you in a similar situation? An initial 30-minute consultation with Maître Zakine (€45) can save you months of procedure — and often much more. Book an appointment →