Lessons from the French Conseil d’État (Dec. 1, 2025, No. 503890 – Commune d’Orbec)
Executive Summary
A recent decision of the French Conseil d’État (Dec. 1, 2025, No. 503890, Commune d’Orbec) clarifies an important rule in public construction law:
Even when a public owner is aware of defects before the formal acceptance of a construction project, the project manager (maître d’œuvre) may still be liable if they fail to properly advise the owner during the acceptance process.
The court held that the owner’s awareness of defects does not fully exonerate the project manager from their professional duty to advise.
However, it may justify reducing the project manager’s liability, which in this case was limited to 50% of the damages.
This decision reinforces a key principle in construction governance:
professional advisory duties remain critical at the moment of project acceptance, even when risks are already known to the client.
Understanding the Legal Context: Acceptance in Public Construction Projects
In French public construction law, acceptance of the works (réception) is a decisive legal milestone.
It typically marks:
- the formal completion of the construction works
- the transfer of responsibility for the structure to the owner
- the starting point of statutory warranties, including the ten-year structural warranty (garantie décennale)
- the termination of most contractual obligations between the owner and contractors
Because acceptance has such significant legal consequences, courts consistently emphasize the importance of professional guidance during this stage.
Project managers, architects, and engineers involved in project supervision are expected to assist the owner in making an informed and legally sound decision regarding acceptance.
The Facts of the Case: Known Defects at the Time of Acceptance
The case concerned a small French municipality of approximately 2,000 residents.
The municipality had commissioned construction works and relied on a project manager responsible for, among other tasks:
- Direction de l’exécution des travaux (DET) – supervision of construction execution
- Assistance aux opérations de réception (AOR) – assistance during the acceptance procedure
Before the formal acceptance of the project, several construction defects had already been identified.
These defects were known both to:
- the municipality (the public owner)
- the project manager supervising the works
Despite this situation, the project manager recommended that the municipality accept the works without any reservations.
The municipality followed that recommendation and formally accepted the works. Later, the defects worsened.
The municipality subsequently sought to hold the project manager liable for failing to properly advise it during the acceptance process.
The Legal Issue Before the Conseil d’État
The central legal question was straightforward: Can a project manager be held liable for failing to advise the public owner about construction defects when the owner already knew about those defects before accepting the works?
The answer from the Conseil d’État was clear: Yes.
The owner’s prior knowledge of defects does not eliminate the project manager’s duty to advise.
The Court’s Reasoning: The Duty to Advise During Acceptance
The Conseil d’État reaffirmed a well-established principle in French administrative construction law.
Project managers owe the public owner a contractual duty to advise (devoir de conseil) during the acceptance process.
This duty includes several concrete obligations:
- identifying defects or irregularities affecting the works
- clearly informing the owner of those issues
- recommending whether reservations should be issued
- warning against accepting the works without reservations when defects are present
The purpose of this duty is to ensure that the owner makes an informed decision at a legally critical stage of the project.
Acceptance without reservations may significantly limit the owner’s ability to later pursue contractual claims against the contractors.
Therefore, the project manager’s advisory role is not merely technical it has legal and financial consequences.
Why the Owner’s Knowledge Does Not Remove Liability
The Conseil d’État emphasized an important nuance.
The fact that the municipality already knew about the defects did not eliminate the project manager’s responsibility.
Why?
Because professional advisors are expected to provide independent technical judgment.
Even when the client is aware of a problem, the project manager must still:
- formally assess the issue
- clearly explain its implications
- recommend the appropriate legal response (such as reservations during acceptance)
In other words, the professional’s role is not limited to repeating what the client already knows.
It is to ensure that the client understands the legal consequences of their decision.
The Key Outcome: Shared Liability
Although the project manager breached their duty to advise, the Conseil d’État also acknowledged the municipality’s own conduct.
The owner had been aware of the defects before acceptance.
This awareness constituted fault on the part of the owner.
As a result, the court concluded that the project manager should not bear the entire financial burden.
Instead, the Conseil d’État held that the owner’s negligence justified limiting the project manager’s liability to 50% of the damages.
This solution reflects a principle frequently applied in administrative liability cases:
when both parties contribute to the damage, responsibility may be shared.
An Important Factor: The Municipality Had No Technical Services
One element highlighted by the court was the lack of internal technical expertise within the municipality.
The local authority had no internal engineering or technical services capable of independently evaluating the defects.
As a result, it relied heavily on the expertise of its project manager.
This dependence strengthened the project manager’s obligation to provide clear and rigorous professional advice.
The ruling implicitly confirms an important idea in construction governance:
The greater the client’s technical dependence on a professional advisor, the greater the advisor’s duty of vigilance.
Practical Lessons for Construction Law Practitioners
For lawyers, architects, engineers, and public procurement professionals, the decision provides several practical takeaways.
- The Duty to Advise Does Not Disappear When the Client Knows the Risk
Professional advisors must still formally analyze and communicate the consequences of known defects.
- Acceptance Is a Legally Sensitive Moment
The acceptance stage is not merely administrative.
It can determine future liability and litigation outcomes.
- Documentation Matters
Professional advice should be clearly documented, especially when recommending acceptance without reservations.
- Shared Liability Is a Real Possibility
Courts may allocate responsibility between the owner and the project manager depending on their respective conduct.
Why This Case Matters Beyond French Construction Law
Although this ruling arises from French administrative law, the underlying principle resonates across jurisdictions.
In complex infrastructure and construction projects worldwide:
- professional advisors play a critical role in risk assessment
- clients often rely on technical expertise when making legally significant decisions
- inadequate advisory processes can lead to long-term liability exposure
The case illustrates a broader governance lesson:
technical advice is inseparable from legal risk management in major projects.
Final Thoughts
The decision of the Conseil d’État (Dec. 1, 2025, Commune d’Orbec, No. 503890) confirms that professional advisory duties remain central during the acceptance of construction works.
Even when defects are known, project managers cannot simply defer to the owner’s awareness.
They must actively ensure that the owner understands the legal implications of accepting the works without reservations.
Where both parties fail to exercise sufficient caution, the result may be shared liability.
For construction professionals and legal advisors alike, the case is a reminder that the most consequential legal decisions in a project often occur at the very end of the construction process precisely when the pressure to close the project is highest.
Source : https://www.conseil-etat.fr/fr/arianeweb/CE/decision/2025-12-01/503890
