A contract provides that, in the event of disagreement, the parties will call on an expert chosen together. The expert delivers a report, and the party the report goes against then argues that a private appraisal (expertise amiable) cannot, on its own, found an order against it. The reported decision of the Third Civil Chamber of the Cour de cassation (the French supreme court for civil and commercial matters) of 8 January 2026 rejects that objection: where the appraisal was carried out under the contract by an expert chosen by mutual agreement, the judge may rely on it exclusively, and has sovereign power to assess its value and scope, that is, without review by the Cour de cassation. The content of the report then becomes decisive.
The facts
The owners commissioning the works (maîtres de l’ouvrage) entrusted a company with a project management assignment (maîtrise d’œuvre, design and supervision of the works) for the rebuilding of two dwellings; the contract was later transferred to another company, the project manager. It contained a clause requiring the parties to use an expert chosen by mutual agreement; according to the appeal, this private appraisal was to take place before any litigation. The contract was terminated while the works were in progress, and the owners sold their property before completion. Claiming various losses, they sued the project manager for damages.
On 12 September 2023 the Besançon Court of Appeal ordered the project manager to pay them one sum for their financial loss and another for their loss of enjoyment; the Cour de cassation’s decision does not give the amounts. In the second ground of its appeal, the project manager argued that the Court of Appeal had relied exclusively on a private appraisal whose evidential value the project manager disputed, both to establish liability and to quantify the loss, whereas the clause did not relieve the owners, who bore the burden of proof, of producing other evidence. It relied on article 16 of the French Code of Civil Procedure and article 6 § 1 of the European Convention on Human Rights.
The decision
The Cour de cassation dismissed the appeal (Cass. 3e civ., 8 January 2026, appeal no. 23-22.803, reported). It set aside without specific reasoning the first ground, manifestly incapable of leading to cassation, and the third, inadmissible (article 1014, paragraph 2, of the Code of Civil Procedure).
On the second ground, it stated the rule and its exception: “While the judge cannot base a decision exclusively on a non-judicial expert report, even an adversarial one, drawn up at the request of one party, it is otherwise where the appraisal was carried out under the contract concluded by the parties by an expert chosen by mutual agreement” (translated from the French).
It then approved the Court of Appeal, which had found that the appraisal “had been carried out under a contractual clause obliging the parties to have recourse to an expert chosen by mutual agreement”. The lower court “correctly deduced” from this that the argument based on the appraisal’s lack of evidential value, “on the ground that it was not a court-ordered appraisal”, could not succeed, and it “assessed, within its sovereign power, the value and scope of the findings and conclusions of that appraisal”. Neither the adversarial principle nor article 6 § 1 of the Convention was breached.
Two conditions emerge from the wording: an appraisal carried out under the parties’ contract, and an expert chosen by mutual agreement. The decision does not say that the report binds the judge, who assesses its value and scope. It rules neither on other situations, such as an expert appointed by one party alone under the contract, nor on how the operations must be conducted.
What this changes for valuation
A case distinct from the single-party report. The principle, laid down by a Mixed Chamber (a formation of several chambers of the Cour de cassation) on 28 September 2012 (no. 11-18.710), is that a report drawn up at the request of one party alone must be corroborated. Two recent decisions have refined it: the judge may rely exclusively on such an appraisal where it concerns an established and undisputed fact (Cass. 1re civ., 15 October 2025, see private report and undisputed fact), and corroboration may come from documents annexed to the report that are not the expert’s own work (Cass. com., 1 April 2026, see annexes and corroboration of a private report). The decision of 8 January 2026 deals with a different situation, that of an appraisal provided for in the contract and entrusted to a jointly chosen expert. These decisions do not contradict each other: the most recent, of 1 April 2026, concerns only the single-party report.
The clause makes the difference. A clause of this kind can appear in a project management contract, as here, but also in a lease, a shareholders’ agreement or a settlement agreement, for a disagreement over a value, a rent or a loss. The Court refers to an appraisal carried out “under the contract concluded by the parties”, without distinguishing by type of contract; the decision says no more. The clause benefits from specifying how the expert is chosen and the scope of the assignment.
An appraisal, not a price fixed by a third party. This appraisal differs from a price left to the estimate of a third party (article 1592 of the French Civil Code) and from the value of company shares set, in the event of dispute, by the expert under article 1843-4 of the same code. In those mechanisms, the third party fixes the figure itself (method binding the third-party valuer, alternative valuations by the article 1843-4 expert). The decision of 8 January 2026 does not mention these mechanisms: in it, the report remains evidence, which the judge assesses with sovereign power.
Everything rests on the content of the report. Once the objection based on the appraisal’s non-judicial nature is set aside, the debate turns to the findings and conclusions. The report must therefore be verifiable: a written instruction (Charte de l’expertise en évaluation immobilière, the French property valuation charter, 6th edition, November 2025, Title II, § 9.1; EVS 4), accepted by both parties in a joint appraisal, no conflict of interest (Title I, § 4.1.3), identified references and annexed documents (Title II, chapter 10; EVS 5), in line with what a valuation report contains. The decision does not make it a condition, but gathering each party’s observations before concluding prepares the report for adversarial debate in court. The party disputing its conclusions can have its references, calculations and assumptions examined in a critical review (seconde lecture).
What the valuer takes from it
- An appraisal carried out under the contract by an expert chosen by mutual agreement can found the judge’s decision on its own.
- The judge has sovereign power to assess its value and scope: the report remains evidence, unlike the figure fixed by a third-party valuer.
- For such a contractual appraisal, the objection based on its non-judicial nature fails; the debate concerns the findings and conclusions.
- The method of appointment and the expert’s assignment are best written into the clause, then into a valuation contract signed by both parties.
Further reading
The Court expert, joint valuation and litigation support in France page describes the assignment formats and their fees. The guide Producing a valuation in a French court: which format to choose? and the glossary entries expertise amiable conjointe, tiers évaluateur and seconde lecture complement this article. The other exception to the 2012 rule: Private expert report: enough for an established, undisputed fact. On the same theme: Private expert report: its own annexes can corroborate it and Independence of a French court expert: assessed case by case. The decision is available on Légifrance.
What next
Does your contract provide for an expert chosen by mutual agreement?
Appointed by both parties, I set the instruction in writing with each of them, gather their observations and deliver a report that annexes its sources. Under such a clause, the judge may rely on this report alone, while assessing its value, and each party can check its findings.
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