An agreed expert appraisal (expertise amiable) provided for in the contract may, on its own, form the basis of the court's decision, provided that it was carried out in performance of the contract by an expert chosen by mutual agreement. The third civil chamber then sets aside the rule prohibiting a court from relying exclusively on a non-judicial expert report drawn up at the request of one party (Civ. 3e, 8 January 2026, No. 23-22.803).
Key points
- A court may not base its decision exclusively on a non-judicial expert report drawn up at the request of one party, even one drawn up on an adversarial basis.
- That prohibition falls away where the appraisal was carried out in performance of the contract entered into by the parties, by an expert chosen by mutual agreement.
- A party may not deprive such a report of probative value on the sole ground that it is not a court-ordered expert appraisal.
- The court makes an unfettered assessment of the value and scope of the findings and conclusions of a report so drawn up.
- Relying on such a report breaches neither the adversarial principle nor the right to a fair trial.
An agreed expert appraisal required by the contract
The third civil chamber dismisses the project supervisor's appeal to the Cour de cassation (France's highest civil court): a report drawn up in performance of a contractual clause, by an expert chosen by mutual agreement, may on its own found an award against it.
Two building owners (maîtres de l'ouvrage) award a project supervision engagement for the reconstruction of two dwellings. That contract is later transferred to another company, which becomes the project supervisor (maître d'œuvre). The building owners terminate the project supervision contract while the works are under way, then sell their property before the works are completed. Alleging various heads of damage, the building owners sue the project supervisor for compensation.
The contract contained a clause requiring the parties to have recourse to an expert chosen by mutual agreement. According to the decision under appeal (CA Besançon, 12 September 2023, No. 22/00578), the project supervisor had relied on that clause to have set aside a court-ordered expert appraisal (expertise judiciaire) sought in summary proceedings (référé). The parties then had recourse to a jointly appointed expert, whose report served as the basis for the debate on liability and on the quantification of the damage.
The court of appeal ordered the project supervisor to compensate a financial loss and a loss of enjoyment on the basis of that report. Before the Cour de cassation, the project supervisor argued that a court cannot rely exclusively on a non-judicial expert appraisal carried out at the request of one party, relying on Article 16 of the French Code of Civil Procedure and Article 6 § 1 of the Convention for the Protection of Human Rights and Fundamental Freedoms.
While a court may not base its decision exclusively on a non-judicial expert report, even one drawn up on an adversarial basis at the request of one party, the position is different where the appraisal was carried out in performance of the contract entered into by the parties by an expert chosen by mutual agreement.
The Cour de cassation therefore approves the court of appeal for having rejected the challenge based solely on the non-judicial nature of the report. The first and third grounds of appeal did not give rise to a specifically reasoned decision, pursuant to Article 1014, paragraph 2, of the French Code of Civil Procedure.
What does an agreed expert appraisal clause change?
A clause requiring recourse to a jointly chosen expert turns the resulting report into a document capable of founding an award on its own.
The reasoning turns on the origin of the report. An appraisal commissioned unilaterally by one party remains a document that the court cannot make the sole basis of its decision. An appraisal organised by the contract, with an expert appointed by mutual agreement, by contrast stems from an agreement of both parties on the mode of proof. A party that has consented to that mechanism can no longer criticise the report for not being judicial.
The consequence is a practical one for the company facing the claim. Challenging the report means discussing its content: the method followed, the material findings, the attribution of the breaches, the figures adopted. The formal argument, based on the absence of a court-ordered expert appraisal, is not enough. The Cour de cassation also points out that the lower court judge makes an unfettered assessment of the value and scope of the findings and conclusions of the appraisal: the report has no automatic authority, but it may carry conviction.
What scope for the non-judicial expert appraisal?
The decision confirms the prohibition on basing a decision exclusively on a unilateral appraisal and recognises an exception of contractual origin.
The principle remains intact: a report drawn up at the request of a single party, even where the other was invited to take part, cannot constitute the sole support for the decision. The decision of 8 January 2026 adds a distinct scenario, that of an appraisal carried out in performance of the contract by an expert chosen by mutual agreement. This is no longer a party appraisal, but an appraisal wanted by both parties.
The court of appeal had noted the particular chronology of the case: the project supervisor had opposed the court-ordered expert appraisal by invoking the clause, before challenging the probative value of the agreed report that resulted from it. The decision under discussion does not say how far the court's freedom extends when faced with such a report, nor how to treat a contractual appraisal conducted irregularly. As the case law stood on 8 January 2026, the solution concerns an appraisal complying with the clause and an expert appointed jointly.
How to secure the probative value of the report?
A prior appraisal clause binds the party that stipulated it: it assists the other party's proof as much as its own.
Three reflexes emerge from the solution. First, the drafting of the clause deserves attention: requiring a single expert chosen by mutual agreement amounts to accepting in advance that the report may suffice for the court. Next, the appointment of the expert and the definition of the expert's remit become decisive moments, since the scope of the remit governs the content of the report. Finally, active participation in the appraisal, through written observations and documents, shapes the later discussion.
A party challenging the outcome is well advised to set competing evidence against the report and to discuss its findings point by point. The case also shows the limits of the report as the sole document: the building owners had not referred their loss of enjoyment to the expert, and the court of appeal substantially reduced the compensation claimed under that head, for want of sufficient evidence. Whatever is not in the report must be proved by other means.
The checks before accepting an appraisal clause
- Check whether the contract requires a prior expert appraisal and whether the expert must be chosen by mutual agreement.
- Bear in mind that this contractual choice may be enough to found an award, without any court-ordered expert appraisal.
- Negotiate the scope of the expert's remit, which will determine the extent of the findings that can be relied on against a party.
- Make observations and produce documents during the appraisal, rather than after the report is filed.
- Confine any challenge to the content of the report, since the argument based on its non-judicial nature is rejected.
- Document separately the heads of damage that the expert was not instructed to examine.
Frequently Asked Questions
Can a non-judicial expert report alone be enough to secure an award against a company?
Yes, where the appraisal was carried out in performance of the contract entered into by the parties, by an expert chosen by mutual agreement. In that case, the Cour de cassation accepts that the court may base its decision exclusively on that report. By contrast, a non-judicial expert report drawn up at the request of a single party, even on an adversarial basis, cannot form the sole basis of the decision.
Is a court-ordered expert appraisal still needed when the contract provides for an agreed expert?
It is not a condition of proof. The third civil chamber held on 8 January 2026 that a report drawn up under a clause requiring an expert chosen by mutual agreement may on its own found the court's decision. Criticising the report for not being a court-ordered appraisal is therefore not enough to deprive it of probative value. The discussion must address its content.
How can a report by a jointly appointed expert be challenged effectively?
By discussing the content of the report: the method followed, the material findings, the attribution of the breaches and the figures adopted. The argument based solely on the non-judicial nature of the report is rejected where the appraisal results from a clause requiring an expert chosen by mutual agreement. The lower court judge retains the power to make an unfettered assessment of the value and scope of the expert's findings and conclusions.
Does a clause requiring a jointly chosen expert prevent an appraisal ordered in summary proceedings?
The decision of 8 January 2026 does not settle that question. It rules only on the probative value of the agreed report obtained under the clause. In the case decided, according to the court of appeal's decision, the court-ordered expert appraisal granted in summary proceedings had been set aside on appeal after the project supervisor invoked the clause, which led the parties to appoint an expert jointly.
Is the court bound by the figures set out in an agreed expert report?
No. Even where the appraisal results from a contractual clause and an expert chosen by mutual agreement, the court makes an unfettered assessment of the value and scope of the report's findings and conclusions. It may adopt the expert's figures, set them aside, or rule differently on heads of damage that the expert did not examine, for want of sufficient evidence produced by the claimant.