Architect's decennial liability: do cracks render a building unfit for its purpose?

You are the owner of a rental property in Château-Gontier. For a few months, cracks have appeared on the façade walls. Nothing serious, you think. But dampness seeps in, tenants complain, and one of them even mentions a problem of unsanitary conditions. Whose fault is it? Can the architect who designed the building five years ago be held responsible? This question is asked by hundreds of owners every year.

The answer is found in a ruling of the Court of Cassation of 27 January 1981 (No. 79-15.320), which established a clear principle: cracks, even without immediate collapse, can render a property unfit for its purpose if they are likely to cause damp infiltration. In that case, it was a clinic in Bordeaux, but the reasoning applies to any building: dwelling, commercial premises, office.

What exactly does this decision say? That the architect incurs his decennial liability (i.e., a ten-year guarantee from the date of acceptance of the works) as soon as the defects compromise the purpose of the structure. And this even if the cracks do not threaten the solidity of the building. A landmark decision, which continues to protect employers, whether in Laval or elsewhere.

The facts: a story like many others

We are in Bordeaux, in the mid-1970s. The company "La Polyclinique de Bordeaux" entrusts an architect with the construction of a building to house its premises. The works are accepted without major reservations in 1972. But very quickly, cracks appear on the façades and inside. Nothing catastrophic in appearance: no wall collapses, no floor gives way. Yet dampness seeps through these cracks, and the operating theatres, patients' rooms and corridors become difficult to use. The clinic has to interrupt some activities, loses patients, and suffers significant economic loss.

The employer (the clinic) sues the architect on the basis of decennial liability. The architect defends himself by arguing that the cracks are superficial, that they do not compromise the solidity of the structure (the classic condition for decennial liability), and that in any case they result from a defect in the soil or from poor workmanship attributable to the contractor, not to him. He also points out that he was not negligent in his supervisory role.

The Bordeaux Court of Appeal, in a judgment of 14 June 1979, ruled in favour of the clinic. It held that the cracks, due to their number and location, "are likely to become a source of dampness inside the premises" and thus render the building unfit for its purpose as a clinic. The architect appealed to the Court of Cassation. The Court of Cassation, by a ruling of 27 January 1981, dismissed his appeal. It approved the Court of Appeal's sovereign finding that the unfitness for purpose was established, and that the architect was therefore liable to compensate the loss on the basis of decennial liability.

The reasoning of the court — dissected

The legal basis of this decision is former Article 1792 of the Civil Code (now Article 1792 since the 1978 reform, but applicable to the dispute). This article provides that any builder of a structure is strictly liable, for ten years from acceptance, for damage which compromises the solidity of the structure or which, affecting it in one of its constituent elements or one of its equipment elements, renders it unfit for its purpose.

The difficulty here was to determine whether non-structural cracks (which do not affect solidity) could fall within this guarantee. The architect argued that they did not: in his view, decennial liability only covers serious defects that threaten the physical integrity of the building. The judges did not follow this argument. They considered that unfitness for purpose is an autonomous concept, distinct from impairment of solidity. Thus, as soon as the defects render the premises unfit for the use for which they are intended, decennial liability is engaged, even if the building remains standing.

In this case, the clinic was intended to receive patients, to provide care, to house convalescents. The dampness caused by the cracks created an unsanitary environment incompatible with this purpose. The judges therefore held that, without having to prove that the cracks endangered the structure, the mere risk that they would become a source of dampness was sufficient to characterise unfitness.

This ruling is important because it broadens the scope of decennial liability. It confirms a jurisprudential trend already underway: the protection of the employer is reinforced, and builders (architects, contractors) must answer not only for solidity but also for the habitability and functionality of the structure.

What this means for you — practically

If you are the owner of a building, whether in Laval or Mayenne, this decision is a powerful weapon. It means that you can invoke the decennial liability of the architect (or contractor) for defects which, without being catastrophic, prevent normal use of the premises.

Take a concrete example: you had a detached house built in Château-Gontier. Five years after acceptance, micro-cracks appear on the external walls. They do not threaten solidity, but rainwater seeps in, causing damp patches and a musty smell in the bedrooms. Your children develop allergies. You can no longer rent out the spare room. According to the 1981 ruling, these defects render the house unfit for its purpose as a dwelling. You can therefore claim compensation from the architect, even if the ten years have not yet expired.

For an owner-landlord, the consequences are direct: if your tenant complains about dampness due to cracks, and this dampness makes the dwelling unsanitary or uncomfortable, you can seek recourse against the builder. Note however that the decennial liability only applies to defects appearing within ten years of acceptance of the works. After that period, you will have to rely on other grounds (latent defects, ordinary contractual liability).

For a purchaser, this case law is also protective. If you buy a property and discover cracks causing dampness, you can take action against the seller (on the basis of latent defects) or, if the property is recent, directly against the builder under the decennial liability. Such an action can save you from costly works: expect between €5,000 and €15,000 to treat cracks and dry out damp walls.

Four tips to avoid this type of dispute

• Have a soil survey carried out before any construction. Unsuitable soil is often the cause of cracking. In Mayenne, clay soils are common; a geotechnical survey (around €1,500) can save you from much more costly defects.
• Require solid guarantees from your builder. Check that your architect and contractor take out compulsory decennial liability insurance. Without this insurance, you will find it difficult to obtain compensation in the event of a claim.
• Draft a detailed acceptance report of the works. Note all reservations, even the smallest. A crack noted at acceptance can be repaired without waiting. If you mention nothing, you risk losing your rights.
• In case of cracks, act quickly. At the first signs, have the defects recorded by a bailiff and inform your insurer. Do not wait for dampness to set in: the damage can worsen and the ten-year period runs quickly.

Further reading: related case law and developments

The 1981 ruling is part of a line of decisions that have gradually broadened the concept of unfitness for purpose. As early as 1977, the Court of Cassation held that water infiltration making a dwelling uninhabitable fell within decennial liability (Cass. civ. 3e, 22 February 1977). More recently, it confirmed that defects in sound or thermal insulation could constitute unfitness (Cass. civ. 3e, 13 January 2016).

The trend is therefore clear: judges are increasingly protecting the employer, to the detriment of builders. For the latter, it becomes imperative to take out solid decennial insurance and to check the quality of materials and techniques used. For owners, this is a safety net: even apparently minor defects can give rise to a right to compensation.

In the future, we can expect the concept of unfitness to extend further, particularly to issues of energy performance or comfort. The courts follow the evolution of standards and occupants' expectations.

What you absolutely must remember

FAQ:

1. Are cracks in my flat in Laval covered by the decennial liability? Yes, if they render the dwelling unfit for habitation (dampness, unsanitary conditions). Otherwise, they fall under the one-year perfect completion guarantee or ordinary contractual liability (5 years).
2. Can I take action against the architect if the cracks appear after 10 years? No, the decennial liability expires at 10 years. After that, you can try an action based on latent defects (2 years from discovery of the defect) or liability for fault (5 years).
3. What are the average costs to repair cracks with infiltration? Between €2,000 and €10,000 depending on the extent. If dampness has caused mould, expect €5,000 to €15,000 for treatment and restoration.
4. What if my builder does not have decennial insurance? You can seek recourse against him personally. But if he is insolvent, you can apply to the Guarantee Fund for Compulsory Insurance (if the contractor was insured but the insurer refuses).
5. Is a mere risk of dampness sufficient to incur liability? Yes, according to the 1981 ruling. It is not necessary that dampness is already present; the risk that it will occur is sufficient if the cracks are likely to cause it.

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 →