Surface difference of less than 1.6%: the Cour de cassation refuses any compensation

In the Paris region, a couple signed a contract for the construction of a detached house. The project was ambitious, with covered terraces and a porch. But at the acceptance of the works (the act by which the employer accepts the work, with or without reservations), a disappointment: the area of certain elements did not quite match the plans. After an expert assessment, a discrepancy of 0.70 m² for the terraces was discovered, representing 1.6% of the planned area, and 0.02 m² for the porch, representing 0.4%. A trifle? Not for these homeowners, who brought the matter to court and sought damages. Their case went all the way to the Cour de cassation. The supreme court has just ruled against them, finding that these minor differences constitute neither an error nor a non-conformity.

But at what threshold does a missing square centimetre become legally significant? This decision of 5 December 2012 provides valuable insight for all property stakeholders. Must any discrepancy be accepted as inevitable, or are there safeguards?

The ruling discussed here recalls a fundamental principle of construction law: not every contractual breach is equal. It must be sufficiently serious to warrant compensation. Explanations.

The facts: a story like any other

It all began on 17 September 2001, when a couple signed a contract for the construction of a detached house with the company Les Demeures d'Helios. The project, located in Île-de-France, involved the construction of several covered outdoor areas, including terraces and a porch. Acceptance of the works took place on 27 January 2003, but it was accompanied by reservations: the homeowners (referred to in law as the employers) reported defects (faults affecting the solidity or use of the works) and in particular challenged the areas stated.

A court-appointed expert (a professional appointed by the court to inform the decision) was appointed. The expert's report did indeed reveal an area discrepancy, but it was tiny: 0.70 m² on the covered terraces, representing 1.6% of the contractual area, and 0.02 m² for the porch, 0.4%. Conversely, no culpable delay in the execution of the works was established. Armed with this finding, the couple brought a claim against the builder.

Their argument: the contract had not been performed. Every promised square metre must be delivered. A discrepancy, however minor, in their view constituted non-conformity (a difference between what was agreed and what was built) and caused them loss. The Paris Court of Appeal, however, was not convinced. It held that these differences fell within the tolerances accepted in the industry and did not amount to a substantial error. The homeowners then appealed to the Cour de cassation.

The court's reasoning – dissected

The Cour de cassation upheld the Court of Appeal's reasoning. For the supreme judges, the trial judges had a sovereign power to find that the discrepancies identified (0.70 m² and 0.02 m²) were too small to constitute an error or non-conformity. They were therefore entitled to conclude that the claim for damages should be dismissed.

The solution rests on a simple procedural principle: the assessment of the existence and seriousness of contractual breaches falls within the sovereign power of the trial judges (the Court of Appeal). In other words, the Cour de cassation does not review the merits of that factual assessment, only the legal correctness of the reasoning. Here, no rule of law had been infringed.

In contract law, in order to obtain compensation under Article 1147 of the Civil Code (in the version applicable to the dispute, which provides that the debtor is liable to damages in the event of non-performance of the obligation), it is still necessary to prove a sufficiently serious breach. A non-conformity must be significant. The Court of Appeal found that this was not the case. Minimal discrepancies, below the usual tolerances in the building industry (which often vary between 2 and 5% depending on the trade), do not warrant an award of damages.

The homeowners' argument – that any difference, however small, gives rise to compensation – was therefore brushed aside. The builder, for its part, was able to show that these discrepancies were negligible and inherent in any technical construction. The Cour de cassation broke no new ground: it confirms a consistent line of case law to the effect that there is no contractual breach where the result accords with the general scheme of the contract. In 1991, for example, it had already held that a 2% area difference did not give rise to compensation (Cass. 3e civ., 3 April 1991, No. 89-17.204). This decision falls in line with that authority.

What this means for you – in practical terms

If you are a homeowner and have had a property built or bought off-plan, this decision should serve as a warning. In Paris, where the price per square metre reaches stratospheric levels (often over €10,000), a loss of 0.70 m² may seem derisory in percentage terms, but would still represent €7,000. Yet, without a serious defect or major discrepancy, the court will not automatically award compensation.

For off-plan purchasers (sale in future state of completion), it is a reminder that the area guarantee (a promise that the property has the stated area) is not absolute. The technical tolerances accepted in the industry can exonerate the builder. If you notice a discrepancy, have a chartered surveyor (a specialist in area measurement) carry out a measurement as soon as possible, because once a year has elapsed after acceptance, remedies become more complicated. And above all, do not embark on major litigation for a 1% shortfall in area if you have not suffered a proven loss of use.

For tenants, the issue is different: the area of a rented dwelling is governed by specific rules (in particular the 2002 decree on decent housing). But if, as a future tenant, you visit a property under construction and sign a lease before completion, pay close attention to the plans.

Finally, for professionals – developers, architects, contractors – this case law is a double-edged sword. It protects you against abusive claims, but it also requires absolute rigour in your measurement schedules (documents quantifying areas). A discrepancy of 5% could well be considered excessive. It is therefore better to include an express contractual clause setting a tolerance to avoid any dispute. As shown by a recent file in my practice, a Parisian developer was able to dismiss a fanciful claim by relying on a 3% tolerance stipulated in the contract.

Four tips to avoid this type of dispute

• Have the tolerances set out in the contract: Negotiate a clause that indicates the acceptable percentage of error on the areas, for example 2% above or below the planned dimensions. In the absence of such a clause, the judge will have a sovereign power to determine what is tolerable.
• Measure by a professional upon acceptance: When you get the keys, do not rely solely on visual inspection. Instruct a chartered surveyor to compare the actual areas with the contractual plans. This will strengthen your case in the event of proceedings.
• Do not exacerbate the dispute over a minor discrepancy: Before bringing a claim, weigh the cost of the proceedings against the expected gain. A case can last for years and cost several thousand euros in legal fees and expert costs. For 0.70 m², the balance is often unfavourable.
• If the loss is real, act quickly: In construction matters, the limitation periods are short. The defects liability period (the obligation to remedy all defects reported within one year of acceptance) is a useful lever. Use a specialist solicitor to send a formal notice (an official letter requiring performance of an obligation) to the builder.
• Keep all supporting documents: Contract, plans, site meeting minutes, correspondence... These documents will be essential to prove the discrepancy and its attribution.

Further reading: related case law and developments

The position of the Cour de cassation is not isolated. In a judgment of 11 January 2010 (Cass. 3e civ., No. 08-21.382), it had already approved the rejection of a claim for a 2.5% discrepancy in the habitable area of a detached house, on the ground that this difference was not significant. Conversely, a difference of 8% had been considered sufficiently serious to justify a price reduction in a similar case (Cass. 3e civ., 14 March 2007, No. 06-12.245).

The trend in the courts is therefore towards proportionality. A tolerance margin of around 5% appears to be emerging as a critical threshold, in line with Article 46 of the Law of 10 July 1965 on co-ownership (which provides that an error of more than 5% in the area of a co-ownership unit entitles the buyer to a price reduction). Although this provision only applies to the sale of flats in co-ownership, it influences judicial practice. In the construction field, in the absence of a specific text, the judge retains a margin of appreciation, but the 5% threshold is becoming a benchmark.

For the future, with the digitisation of plans and the use of BIM (Building Information Modeling), area discrepancies should decrease. But in the meantime, this decision reminds homeowners that they must prioritise issues so as not to incur disproportionate costs.

Key takeaways

Do you find yourself in a similar situation? An initial 30-minute consultation with Maître Zakine (€45) can save you months of proceedings – and often much more. Book an appointment →