Res Judicata in Property Law: Can the Same Case Be Retried?

Imagine: you rent a flat in Riom, and the landlord tells you the area is 70 m². After a few months, you realise it is only 60. You take the case to court to obtain a rent reduction. The judge rules against you, and the decision becomes final. Do you think you can come back and claim damages for the loss of enjoyment suffered? Many would answer no, citing the principle of res judicata: once a court has decided, the same matter cannot be reopened. Yet the Court of Cassation has recently opened a gap.

The question that troubles every landlord or tenant: can the same situation give rise to two separate lawsuits? The answer is nuanced. The judgment of 16 September 2009 (No. 08-10.487) enlightens us: it all depends on the object of the claim. If the first action was for rent reduction, a second action for damages for loss of enjoyment is not necessarily identical. Thus, res judicata does not bar it.

This article analyses this major decision. You will understand the facts, the reasoning of the judges, and above all what it changes for you in practice. Whether you are a landlord in Issoire or a tenant in Clermont-Ferrand, these rules concern you. And if you are in the middle of a dispute, some expert advice could save you time (and money).

The Facts: A Story Like Many Others

Mr X, owner of a building in Riom, leases a flat to Mrs Y. The lease states an area of 80 m², but Mrs Y discovers after moving in that the actual area is only 70 m². She then sues Mr X before the tribunal d'instance of Riom to obtain a rent reduction based on the discrepancy in area. In 2003, the Rennes Court of Appeal dismisses her claim, finding that the loss is not established. This decision becomes final.

But Mrs Y does not stop there. She starts a new procedure, this time to obtain damages for the loss of enjoyment suffered due to the reduced area. She considers that living in a smaller home than expected caused her daily discomfort, justifying separate compensation beyond a simple rent reduction. The Riom court, and then the Rennes Court of Appeal, oppose res judicata from the 2003 judgment: the issue of loss relating to the area was already decided.

Mrs Y appeals to the Court of Cassation. She argues that the claim for rent reduction and the claim for damages do not have the same object. The first aims to adjust the rent to the actual area; the second aims to compensate for a personal loss of enjoyment. The Court of Cassation agrees with her. In its judgment of 16 September 2009, it quashes the Rennes Court of Appeal's decision and remands the case to the same court, differently composed, to rule again on the merits of the loss of enjoyment.

The Reasoning of the Court — Explained

The Court of Cassation relies on Article 1351 of the Civil Code (former, now Article 1355), which provides: 'Res judicata applies only to what has been the subject of the judgment. The thing claimed must be the same; the claim must be based on the same cause; the claim must be between the same parties, and brought by and against them in the same capacity.' In other words, for a second action to be inadmissible, the claim (object), the cause (legal basis), and the parties must be identical.

In this case, the Rennes Court of Appeal considered that the claim for damages was barred by res judicata from the 2003 judgment, on the ground that the compensation sought was calculated as a percentage of the rent. But the Court of Cassation dismisses this argument: 'it is irrelevant that the compensation sought was calculated as a percentage of the rent.' What matters is the object of the claim. In the first instance, Mrs Y sought a rent reduction (modification of the lease price). In the second, she sought damages (compensation for personal loss). These two objects are distinct.

The Court thus recalls a fundamental principle: res judicata does not extend to what has not been decided. Even if the facts are identical (reduced area), the claims may be different. This solution is consistent in the case law of the Court of Cassation. It prevents a party from being deprived of a right because they did not think to claim it in a previous proceeding. It is an application of the maxim 'the judge cannot rule ultra petita' (beyond what is requested).

Note that the decision was handed down by the Third Civil Chamber, specialised in property disputes. It follows a line of judgments that protect the right of access to a judge, avoiding an overly broad interpretation of res judicata.

What This Changes for You — In Practice

For landlord-lessors: if a tenant has already lost a case for rent reduction, they can still sue you for damages for loss of enjoyment. Do not think the first decision protects you. For example, in Issoire, a landlord saw his tenant obtain €2,000 in damages after losing a first action for rent reduction. The Court of Cassation upheld this second action.

For tenants: if you have suffered a loss of enjoyment (noise, reduced area, hidden defect) and have already brought an action for performance of the contract (rent reduction, works), you can still claim damages for your personal loss. However, be careful: the first action must not have already included this claim. If you claimed both rent reduction and damages, and the judge rejected both, res judicata will apply.

For purchasers: if you buy a property and discover a hidden defect, you can combine an action for price reduction (actio aestimatoria) and an action for damages for the loss suffered. The first does not exhaust the second. This is what the Court of Cassation recalls in this judgment.

For co-owners: if the managing agent commits a fault (failure to maintain), you can first request the performance of works, and then later claim damages for the loss suffered during the period without works. Res judicata will not be opposed if the claims are distinct.

In summary, this decision gives you a second chance, provided you formulate a different claim. But do not delay: actions for contractual liability are subject to a 5-year limitation period from the manifestation of the loss (Article 2224 of the Civil Code).

Four Tips to Avoid This Type of Dispute

• Have the area measured by a professional before signing a lease or a sale deed. In Riom, a landlord avoided a lawsuit by hiring a surveyor. The cost (about €200) is negligible compared to legal fees.
• In case of dispute, formulate all your claims from the first instance. If you are a tenant suffering a loss of enjoyment, claim both rent reduction and damages. This way, you avoid a second lawsuit and the uncertainty that goes with it.
• Keep all evidence of your loss: photos, letters, witness statements. Without evidence, no damages. A tenant in Issoire obtained €1,500 thanks to a notebook in which he recorded the noise nuisance every day.
• Consult a lawyer before bringing an action. A professional can advise you on cumulating claims and respecting time limits. In Clermont-Ferrand, Maître Zakine can see you for a consultation for €45 and save you many disappointments.

Further Analysis: Related Case Law and Developments

This judgment is part of consistent case law. Already in 2005, the Court of Cassation held that res judicata cannot be opposed to a claim for damages based on a loss distinct from that already compensated (Civ. 1re, 8 Nov. 2005, No. 02-18.558). More recently, in 2018, the Court specified that a claim for termination of the lease and a claim for payment of rent have different objects, and the first does not prevent the second (Civ. 3e, 7 June 2018, No. 17-16.430).

The trend is therefore towards a strict interpretation of res judicata, favourable to the claimant. Lower courts (tribunals and courts of appeal) sometimes tend to extend this authority to extinguish disputes, but the Court of Cassation calls them to order. In the future, we can expect this solution to be maintained, or even strengthened, for the protection of litigants.

However, be careful: if the first instance already examined and rejected the loss of enjoyment (for example, if the tenant claimed damages and was dismissed), the second action will be inadmissible. So we must distinguish according to what was actually decided.

Checklist Before Acting

• Have I already brought a legal action for the same facts? If yes, check exactly what was claimed. If the claim was different (e.g., rent reduction vs. damages), you can act again.
• Is my loss clearly distinct from that already compensated? For example, if you obtained a rent reduction for reduced area, the loss of enjoyment (discomfort, stress) is not automatically included. You can claim it separately.
• What is the limitation period? Actions for contractual liability are subject to a 5-year period from the discovery of the loss. If the loss is ongoing (e.g., persistent noise), the period runs from the last harmful event.
• What documents should I gather? Lease, sale deed, correspondence, photos, witness statements, previous court decision. Any evidence proving the loss and the absence of a previous claim on this point.
• Do I need a lawyer? Yes, especially if the procedure is complex. A lawyer specialising in property law, such as Maître Zakine, can assess your chances and assist you before the courts of Riom, Issoire or Clermont-Ferrand.

Are you in a similar situation? A first 30-minute consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →