The expropriation judge (juge de l’expropriation, the civil judge who sets compulsory purchase compensation) fixes the compensation for a plot after deducting the cost of the decontamination works the project requires; the former owners then claim that the municipality did not carry them out. Can they seek an expert appraisal of the facts once the compensation has been irrevocably fixed? The Rennes Court of Appeal had denied them any standing (intérêt à agir), that is, the right to have their application examined by the court. On 13 February 2025, the Third Civil Chamber of the Cour de cassation (the French supreme court for civil and commercial matters) quashed that decision: standing does not depend on prior proof that the action is well founded.
The facts
A municipality (commune) compulsorily purchased a plot belonging to a couple. By an irrevocable judgment, the expropriation judge set the principal compensation for dispossession (indemnité principale) owed by the municipality, taking into account the cost of the decontamination works needed to carry out the project declared to be in the public interest (déclaration d’utilité publique): a deduction (abattement) was made on that basis.
The owners then argued that the municipality had not carried out those works and had thus been enriched at their expense, and sued it for an expert appraisal.
On 6 July 2023, the Rennes Court of Appeal held their application for an appraisal inadmissible for lack of standing and ordered them to pay €1,000 to the municipality under article 700 of the Code of Civil Procedure (legal costs), plus the costs of the appeal. As summarised by the Cour de cassation, the Court of Appeal relied on two grounds: the expropriation judge’s decision making the deduction “entailed no obligation for the municipality to carry out the said works”; and “the dispute over the amount of the expropriation compensation has been irrevocably decided” (translated from the French).
The owners appealed: in their view, the obligation to carry out the works went to whether the requested appraisal was well founded, not to whether the application was admissible.
The decision
The Cour de cassation partly quashed the judgment (Cass. 3e civ., 13 February 2025, appeal no. 23-21.815, unreported), under article 31 of the Code of Civil Procedure. It recalled that, under that text, “an action is open to all those who have a legitimate interest in the success or dismissal of a claim”.
It then held: “By so ruling, whereas standing is not conditional on prior proof that the action is well founded, that is, in this case, of the legitimate reason to preserve or establish, before any trial, evidence of facts on which the resolution of the dispute might depend, the Court of Appeal violated the above-mentioned text.”
The wording echoes article 145 of the same code, which the decision does not cite: that article allows an investigative measure to be ordered before any trial where such a legitimate reason exists. It follows that the Court of Appeal’s two grounds, no obligation to carry out the works and compensation irrevocably fixed, could not ground inadmissibility; they belong, where relevant, to the examination of the legitimate reason.
The quashing covers only the inadmissibility and the costs orders under article 700 and for the appeal; the case was sent back to the Angers Court of Appeal. The other grounds of appeal were not examined.
The decision does not say whether the legitimate reason exists, whether the municipality had to carry out the works, or whether the owners have a claim against it: those points remain to be decided.
What this changes for valuation
A deduction costed on future works. The judge deducted the cost of future works deemed necessary for the project, and the compensation is fixed. The owners allege that the municipality was enriched at their expense; the Court of Appeal had ruled out any obligation to carry out the works, and the Cour de cassation did not rule on that point. A decontamination deduction may also reflect the lower value of polluted land. If the works have not been carried out, the comparison between the sum deducted and the actual expenditure is a question of fact, which the requested appraisal aims to establish. It is the reverse of the case decided on 30 January 2025, where completed works had been deducted from the value of the units: Compulsory purchase: completed works and cellars in the indemnity.
Material facts to reconstruct. The nature and amount of the works used for the deduction, from the judgment and the documents produced at the time; the works actually carried out, with their dates, contracts and invoices; the current condition of the land. Soil pollution surveys are a specialist’s task: the Charte de l’expertise en évaluation immobilière (the French property valuation charter, 6th edition, November 2025, Title II, chapter 10) excludes them from property valuation. The valuer reconstructs the compensation calculation, isolates the deduction and sets it against the documented expenditure.
Supporting the deduction when compensation is set. A reported decision of 4 April 2019 already requires the judge to answer a request for a pollution deduction (Compulsory purchase in a ZAC: utilities, pollution and remainder). The report produced before the expropriation judge ties that deduction to an identified costing, a contractor’s quote or a specialist consultancy’s study, rather than to a percentage (Prefer a quote to a flat-rate deduction: French pre-emption case). It specifies whether the cost relates to the use adopted to value the property or to the project, and states that the works have yet to be carried out: the Charte requires assumptions to be stated in the report and, where an uncertain one weighs significantly on the value, the possible impact of its not being borne out to be stressed (Title III, § 1.2). A deduction so described can be checked afterwards.
Establishing facts, not revaluing the property. The report does not redo the valuation of the plot: it measures the facts on which a future action might depend. Whether those facts give rise to a claim against the municipality is for the court.
Two other recent rulings of the same chamber decide separate questions: the classification of a partial taking by reference to the whole plot (Partial compulsory purchase: classify the plot, not the strip) and lost rental income claimed for the first time on appeal (Compulsory purchase: lost rental income can be claimed on appeal).
What the valuer takes from it
- The standing of owners seeking an appraisal before any trial does not depend on prior proof that their action is well founded; the legitimate reason goes to whether the application is well founded, which the court assesses when deciding whether to order the appraisal, not to its admissibility.
- A deduction costed on future works rests on an assumption about those works: the report presents it as such and specifies its nature, cost and source.
- The amount deducted is reconstructed from the judgment and the case documents, then compared with the works actually carried out and paid for; soil surveys are a specialist’s task.
- The decision, unreported, leaves open the legitimate reason and any claim against the municipality: the Angers Court of Appeal will rule again on the application.
Further reading
The Compulsory purchase and pre-emption page describes the assignment, its timescale and its fee. The guide Producing a valuation in a French court: which format to choose? and the glossary entries abattement, indemnité principale and juge de l’expropriation complement this article. The two related rulings are discussed in Partial compulsory purchase: classify the plot, not the strip and Compulsory purchase: lost rental income can be claimed on appeal. On the same theme: Compulsory purchase: completed works and cellars in the indemnity and Amicable sale after a public utility declaration: still a sale. The decision is available on Légifrance.
What next
Was a decontamination deduction taken off your compulsory purchase compensation?
I reconstruct what the deduction set by the judge covered and compare it with the works actually carried out, with a soil specialist where needed. The report sets out the result of that comparison, with supporting documents, for your lawyer or for the expert appointed by the court.
Free quote, by email or by phone. No commitment before the quote is accepted. Fees are never linked to the value of the property (Charte de l’expertise, Title I, §2.1).
