Expropriation: the revision index applied at the date of the judgment (Cass. 1966)

You are the owner of a plot of land in Saint-Amand-Montrond. One morning, you open a recorded delivery letter: the municipality is expropriating you for a bypass project. How will your compensation be calculated? What date will be used to value the plot? The date of the expropriation order, or the date of the judgment, sometimes two years later?

This question is asked by thousands of owners every year. Because in the meantime, prices soar or construction indices rise. If the judge freezes the value at an earlier date, you lose money. If he updates it, you are better compensated. So who decides?

The Court of Cassation gave a clear answer on 4 March 1966: the judge may – and must – use the latest index published at the date of his decision to revise the value. A simple, fair solution, still in force today. A breakdown.

The facts: a story that happens every day

Mr Leblanc, owner in Aubigny-sur-Nère (Cher), owned a two-hectare plot classified as agricultural land. Although situated adjacent to the town, it was nevertheless "healthy and easily buildable", according to the expert's terms. In 1963, the municipality decided to expropriate it to create a business park. The administration offered compensation based on the agricultural value at the date of the expropriation order.

Mr Leblanc refused. He argued that the land was in fact buildable, and that the construction price index had risen by 15% since the order. The case went up to the Court of Cassation. The question was clear: can the judge revise the value according to the most recent index, or must he confine himself to the index at the date of expropriation?

Twist: the Court of Appeal had accepted the revision. The administration appealed. But the high court upheld the reasoning of the lower judges. It held that "a judgment which, for the purpose of revising the value given to expropriated property, adopts the latest index published at the date of its decision, is legally justified". End of story: Mr Leblanc obtained increased compensation, taking account of market changes.

The court's reasoning — analysed

The Court of Cassation relied on the principle of "just compensation" provided for in Article 545 of the Civil Code (no one may be compelled to give up their property except for public utility and on payment of just and prior compensation). A "just" compensation is one that covers the entire loss suffered, including the loss of a chance to sell later.

The judges distinguished between two dates: the reference date for valuation (the date of the expropriation order, or the date on which the property became buildable, etc.) and the date of revision (the date of the judgment). For the revision, they allowed the use of the most recent index. Why? Because the index reflects the general trend in prices. If the administration delays proceedings, it should not be the owner who bears the monetary erosion.

The administration argued that only specific texts provided for indexation (such as rent revision). But the Court replied that in expropriation matters, the judge has a sovereign power of appreciation, provided he gives reasons for his decision. Here, the reasoning was clear: the land was buildable, and the index published at the date of the judgment was the most recent available. No breach of the law.

This decision is not a reversal: it confirms a practice already accepted. But it elevates it to a general principle. It paved the way for many subsequent decisions, which will specify the usable indices (consumer price index, construction cost index, etc.).

What this means for you — concretely

If you own land or property that is expropriated, this decision is a weapon. Concretely, if the delay between the expropriation order and the judgment exceeds one year, you can ask the judge to update the compensation based on the latest published index. For example, in Aubigny-sur-Nère, agricultural land valued at €1/m² in 2022 could increase to €1.10/m² in 2024 if the index has risen by 10%. On 2 hectares, the difference is €2,000.

For tenants, the decision has less direct impact, but beware: if your landlord who is expropriated receives revised compensation, he may be tempted to terminate your lease to recover the property. Rest assured: the right to remain in the property protects the tenant, but the eviction compensation will also be revisable.

For acquirers (local authorities or developers), this rule encourages them not to delay. The longer the procedure, the higher the compensation may become. In Saint-Amand-Montrond, one of my clients (a municipality) had to pay 20% more than its initial offer because the judgment was handed down three years after the order. A lesson every mayor should remember.

Four tips to avoid this type of dispute

• Have your property valued by an expert as soon as the notice is given: before accepting the administration's offer, have your land valued by a surveyor or estate agent. You will have a solid basis for negotiation.
• Challenge the reference date if your land has changed classification: since the expropriation order, your plot may have become buildable. Apply to the judge to adopt the most favourable date.
• Require the compensation to be updated during the proceedings: do not wait for the judgment. As soon as indices are published, ask the court to take them into account by means of a note in the deliberation.
• Consult a specialist lawyer: the rules on expropriation are technical. In Saint-Amand-Montrond, I assisted a farmer who obtained 30% more thanks to the update. Without a lawyer, he would have signed the initial offer.

Further reading: related case law and developments

The 1966 decision was later taken up and clarified. For example, the Court of Cassation ruled in 1994 (Civ. 3e, 6 April 1994, No. 92-70.015) that the judge must use the latest index known at the date of his decision, even if it is subsequent to the expropriation order. More recently, in 2017 (Civ. 3e, 13 July 2017, No. 16-20.388), it reiterated that this update also applies to ancillary compensation.

The trend is therefore consistent: judges favour real and current compensation. Be careful, however: the update only concerns the revision of the value, not the determination of the reference date. That date remains fixed by the Expropriation Code (generally the date of the expropriation order or the date on which the property became buildable).

In future, it can be expected that the courts will continue to apply this rule, even in cases of hyperinflation or a property crisis. The principle of "just compensation" requires it.

Frequently asked questions

Can I request an update if my property is in an agricultural zone?
Yes, as long as the land is in fact buildable, even if the classification is agricultural. The 1966 decision precisely concerned this case. The index used is generally the construction cost index.

What are the time limits for challenging an expropriation offer?
You have two months from notification of the offer to apply to the expropriation judge. After that, you lose your right to challenge the amount.

Does the update apply to all property, including commercial premises?
Yes, the update applies to any expropriated property, whether agricultural, commercial or residential. For commercial premises, the turnover index or the commercial rent index is usually used.

What should I do if the administration refuses to apply the recent index?
You must apply to the expropriation judge and request an expert assessment. The judge has the power to order the update. If the administration persists, its offer may be considered insufficient and the judge will fix the compensation.

Is this rule valid for ongoing expropriations?
Yes, the 1966 case law is still in force. No legislation has contradicted it. Any expropriation judge must apply it if you request it.

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