A contractual investigative measure with legal effects equivalent to those of a judicial expert assessment.
Conventional expertise is an investigative measure whereby the parties to a dispute jointly appoint an independent technical expert to clarify a technical issue. Far from being a mere informal consultation, it is a structured mechanism whose value lies as much in its flexibility as in the strength of its legal effects.
This expert assessment is based first and foremost on the will of the parties. It takes the form of an agreement signed by the parties and their lawyers, which sets its scope. The parties freely choose the expert and determine the extent of the assignment themselves, without any prior involvement from a judge. They also agree on the funding of the assessment: the expert's fee is set and allocated by mutual agreement. Lastly, this agreement offers great flexibility in timing, as it can be entered into before any legal proceedings, on a preventive basis, or during proceedings, to clarify a technical issue in the judicial debate.
Although its origin is contractual, its conduct is nonetheless subject to a protective legal framework. The adversarial principle applies: the expert must submit their findings to the parties before reaching conclusions. Strict guarantees of impartiality and independence apply to the appointed expert, just as they do for a court-appointed expert. The expert operations are also covered by professional confidentiality, with only the final report intended to be shared and, where applicable, produced in court.
Conventional expertise is not limited to a technical opinion devoid of legal weight: it produces significant legal effects. Its written report carries an evidentiary weight equivalent to that of a judicial expert report. As a corollary of this principle, a judge cannot dismiss the report merely because it is conventional in origin — it must be examined on the same footing as any other evidence submitted to the proceedings. Lastly, entering into the agreement has a notable procedural effect: it suspends limitation periods, thereby protecting the parties while awaiting the expert's conclusions.