Buying a new home, building one’s own house, or taking delivery of a real estate development project often represents the culmination of a long-term, financially demanding and emotionally invested undertaking. When, a few months or a few years later, cracks appear on the façades, water infiltration occurs through the roof, the tiling comes loose, the foundations move, or a defect in waterproofing renders part of the property unusable, the shock is all the more painful given that the building was supposed to be recent and built in accordance with industry standards. Disappointment quickly turns into very concrete and pressing questions: who is liable, what remedies can be exercised, within what time limits should one act, and with what chances of success?
French law has long provided a particularly protective framework for project owners and purchasers of new properties. This framework, structured around the legal warranties of construction and complemented by a mandatory insurance system, makes it possible to engage the liability of construction professionals and their insurers when defects affect a recent building. Yet one must understand its mechanisms, identify the right contacts, comply with often strict time limits, and build a sufficiently solid case to assert one’s rights.
This article aims to explain, in an accessible yet legally rigorous manner, how to react when faced with defects in a recent building, what remedies are available against the various stakeholders involved in the construction project, and how to secure a situation that can quickly become technically, financially and legally complex. It is intended for individuals who have built or purchased a new property, for real estate investors confronted with defective workmanship affecting a rental asset, and for those leading off-plan acquisition projects (so-called « VEFA » sales).

Understanding the Concept of Defect in a Recent Building

A Generic Term Covering a Wide Range of Realities

The term « defect » (« désordre » in French) is widely used in construction law, but it does not always carry the same meaning depending on the context. Generally, it refers to any flaw, anomaly, deterioration or non-compliance affecting a constructed work. This may include a structural or aesthetic crack, water infiltration, a defect in thermal insulation, an equipment malfunction, floor subsidence, rising damp by capillarity, an acoustic issue between dwellings, an incorrect slope on a terrace, or even non-compliance with the building permit or urban planning rules.
Not all defects are equivalent, and the law draws a precise distinction between those that justify the application of a legal warranty and those that fall under ordinary contractual liability. This distinction is not merely theoretical: it determines who can be held liable, the time limits for action, the possibility of mobilising insurance coverage, and the scope of the compensation that may be obtained.
Thus, the same apparent defect — for instance a crack — may, depending on its size, location, evolving nature and consequences, fall under the ten-year decennial warranty, the warranty of perfect completion, the warranty of proper functioning, or simply constitute an aesthetic flaw without particular significance. This is why it is essential, as soon as a defect appears, not to qualify it too hastily and to seek professional support to correctly analyse the situation and choose the most effective course of action.

When is a Building Considered « Recent » Under French Construction Law?

Under French construction law, a building is considered « recent » as long as the formal acceptance of the works (réception) took place less than ten years ago. The acceptance is a fundamental legal act: it marks the official completion of the works and constitutes the starting point of all legal warranties. It may be express, through the signing of an acceptance protocol, or tacit, when the project owner takes possession of the works without express reservations. In some cases, acceptance may even be judicial, pronounced by a court in the event of a dispute over the completion of the works.
This ten-year period constitutes the core of the protection offered by the legislator. It corresponds to the duration during which construction professionals are presumed liable for the most serious defects affecting the works. Before the expiration of this period, successive and complementary mechanisms come into play to cover different types of defects: the warranty of perfect completion during the first year, the warranty of proper functioning for two years, and the decennial warranty up to the tenth anniversary of acceptance.
This articulation is essential. It provides protection covering both minor defects detected early in the building’s life and more serious defects that may emerge later, sometimes several years after the completion of the works. One must, however, know how to activate the right warranty at the right time, as each mechanism has its own conditions of application, identified obligors, and expiration deadlines.

The Main Liability Regimes Applicable to Defects in a Recent Building

The Warranty of Perfect Completion (Article 1792-6 of the French Civil Code)

The warranty of perfect completion is the first that can be invoked. Set out in Article 1792-6 of the French Civil Code, it is borne by the contractor who carried out the works and covers all defects reported by the project owner during the year following acceptance. This warranty has a deliberately broad scope: it applies both to reservations made at the time of acceptance and to defects that emerge afterwards, without any condition of particular seriousness.
The contractor is required to repair, within a time frame agreed with the project owner, all reported defects. If no time frame has been specified, the contractor must intervene within a reasonable period. Failing performance, the project owner may, after a formal notice that has remained without effect, have the works carried out by another company at the cost and risk of the defaulting contractor.
The advantage of this warranty is that it covers all types of defects, whether aesthetic flaws, imperfect finishes, minor malfunctions, or more serious shortcomings. It therefore constitutes a valuable tool during the first year, provided that defects are reported promptly and in writing. This is also why it is strongly recommended, during the twelve months following acceptance, to carry out a careful inspection of the property and to report any anomaly observed without delay.

Case Study No. 1 — The Tiled Bathroom that Deteriorates
A couple takes delivery of their new house built by a single-family home developer. Three months after delivery, several bathroom tiles come loose and a shower joint shows signs of cracking. The couple immediately sends a registered letter to the developer, attaching dated photographs and requesting repair works under the warranty of perfect completion.
The developer, initially cooperative, eventually delays intervention. The couple then sends a formal notice to proceed with repairs within three weeks. This step remains without effect. On the basis of Article 1792-6, the couple may engage another company to carry out the repairs and claim the cost from the defaulting developer.
Lesson: the warranty of perfect completion does not require proof of fault. The mere fact that the defect appeared within the year and was reported in writing is sufficient to activate the warranty. Promptness in reporting and written traceability are decisive.

The Two-Year Warranty or Warranty of Proper Functioning (Article 1792-3 of the French Civil Code)

The two-year warranty, also known as the warranty of proper functioning, is provided for in Article 1792-3 of the French Civil Code. It covers, for two years from acceptance, defects affecting equipment items that are dissociable from the works. This concerns elements that can be removed, dismantled or replaced without damaging the building: roller shutters, interior doors, taps, non-built-in radiators, integrated kitchen equipment, home automation devices, certain removable coverings, independent water heaters, and so on.
The purpose of this warranty is to cover functional elements that, while not affecting the structure of the building, may nonetheless compromise its normal use. Thus, a roller shutter that no longer works properly, a dissociable boiler that breaks down, or a door that no longer closes correctly may, depending on the circumstances, justify the application of the two-year warranty.
The distinction between dissociable and non-dissociable elements is not always straightforward, and case law has occasionally produced nuanced decisions. The same equipment may, depending on how it is installed and integrated into the building, fall under either the decennial warranty or the two-year warranty. This qualification has significant consequences, particularly regarding the duration during which the project owner may act and the possibility of mobilising the damage insurance.

Case Study No. 2 — The Defective Heating System
A family has an individual house built. Eighteen months after acceptance, the heat pump installed by the heating company breaks down repeatedly and ultimately becomes completely inoperative in the middle of winter. The family is left without heating for several days.
Since the heat pump is an item of equipment dissociable from the works (it can be replaced without affecting the structural elements), the family acts on the basis of the two-year warranty under Article 1792-3. They send a registered letter to the heating company detailing the repeated breakdowns and requesting repair or replacement of the equipment.
The company refuses, alleging improper use. A court-ordered expert assessment is requested in summary proceedings: the expert concludes that the issue stems from a defective installation. The family obtains in court the replacement of the equipment, compensation for the additional heating costs incurred during the breakdown period, as well as compensation for the loss of enjoyment suffered.
Lesson: the qualification as a dissociable element is central. When doubt exists between the two-year warranty and the decennial warranty, it is often prudent to invoke both grounds in initial steps to avoid losing rights through a misqualification.

The Decennial Warranty (Article 1792 of the French Civil Code)

The decennial warranty is probably the best-known and certainly the most important component of the legal protection scheme for project owners. Set out in Article 1792 of the French Civil Code, it binds construction professionals for ten years from acceptance and covers defects of a certain seriousness. More precisely, it applies to damage that compromises the solidity of the works or that, affecting one of its constituent elements or one of its equipment elements, renders it unfit for its intended purpose.
This definition warrants some explanation. The solidity of the works is compromised when the very structure of the building is at stake: partial collapse, floor subsidence, significant structural cracks, defective foundations, defects affecting load-bearing walls or the framework. Unfitness for purpose, on the other hand, refers to defects that prevent normal use of the property: recurring water infiltration making a dwelling unsanitary, a defect in roof waterproofing, serious malfunctions of a central heating system, acoustic issues making a dwelling uninhabitable, or the presence of pollutants compromising the health of occupants.
The decisive advantage of the decennial warranty is that it rests on a presumption of liability. In other words, the project owner or purchaser does not have to prove fault on the part of the construction professional. They simply need to establish the existence of the defect, its seriousness within the meaning of Article 1792, and its emergence within the ten-year period following acceptance. The construction professional may only be exonerated by proving an external cause: force majeure, the act of a third party, or the fault of the project owner. This reversal of the burden of proof represents considerable protection for the claimant.

The Particular Case of Evolving Defects

Case law has accepted that a defect emerging before the expiry of the decennial period but worsening thereafter remains covered by the warranty. Thus, cracks that appear in the eighth year following acceptance and subsequently spread may engage the decennial liability of the construction professional, provided that the action is brought before the expiry of the ten-year period. This is why it is crucial, as soon as a defect is observed, not to wait for it to worsen: prudence requires acting quickly to interrupt the limitation period and preserve one’s rights.

So-Called Intermediate Defects

Alongside defects clearly falling under the decennial warranty or the other legal warranties, there exists a category of so-called « intermediate defects ». These are defects that do not present the seriousness required to fall under the decennial warranty, but go beyond mere completion defects. For these defects, the project owner may act on the basis of ordinary contractual liability, provided that fault on the part of the construction professional can be demonstrated. The limitation period is then also ten years from acceptance, but engaging liability is more difficult, as it does not benefit from the presumption regime.

Case Study No. 3 — The Evolving Structural Cracks
An investor acquires in 2018 a new rental building under an off-plan sale (VEFA). In 2024, six years after delivery, significant cracks appear on the building’s façades, some of them through-wall cracks. A consulting engineer engaged by the co-ownership association identifies a design defect in the foundations, which fail to take into account the characteristics of the clay soil.
The defects compromise the solidity of the works and ultimately threaten its stability. They therefore clearly fall under the decennial warranty. The co-ownership association, on behalf of the co-owners, files a claim with the damage insurer (assurance dommages-ouvrage) and simultaneously initiates summary proceedings to obtain a court-ordered expert assessment.
The appointed expert concludes that the defect is jointly attributable to the developer (in its capacity as a construction professional under Article 1792-1) and the consulting engineering firm. Both are ordered jointly and severally (in solidum) to finance the repair works on the foundations, valued at €850,000, as well as to compensate the loss of enjoyment suffered by occupants during the repair works.
Lesson: the decennial warranty covers defects compromising solidity, without the need to prove fault on the part of the construction professional. The joint and several condemnation allows the claimant to turn to the most solvent party, who may then in turn seek recovery from the other parties at fault.

Case Study No. 4 — Chronic Infiltration through the Roof Terrace
A real estate investment company acquires in 2020 a new commercial unit integrated into a mixed residential-commercial building. Starting in 2022, recurring water infiltration occurs through the roof terrace during each rainfall event. Water seeps into the unit, damages coatings, harms stored merchandise, and ultimately compromises commercial operations.
Although the structure of the works is not compromised, the infiltration renders the property unfit for its commercial purpose. The decennial warranty therefore applies. The company files a claim with its damage insurer and simultaneously sends a formal notice to the waterproofing contractor and the developer.
The expert assessment reveals an execution defect in the waterproofing, with under-dimensioned upstands and an absence of mechanical protection. The damage insurer covers the repair works for €180,000 and compensates the operational losses suffered by the commercial tenant, amounting to €95,000, which it then recovers from the decennial liability insurer of the waterproofing contractor through subrogation.
Lesson: unfitness for purpose does not require a collapse; it is sufficient that normal use of the property be prevented. For an investor, operational losses and rental losses constitute compensable damages as consequential intangible damages.

Identifying the Potentially Liable Stakeholders

The Construction Professional, Principal Debtor of the Legal Warranties

Within the meaning of Article 1792-1 of the French Civil Code, any person bound to the project owner by a contract for services (contrat de louage d’ouvrage) is considered a construction professional. This definition is deliberately broad and includes many stakeholders: contractors, craftsmen, architects, project managers, technical engineering firms, but also sellers of buildings to be constructed, real estate developers, and single-family home developers.
This plurality of potentially liable parties offers a significant advantage to the project owner. In the event of a defect, they may, in principle, take action against all the construction professionals who contributed to the works in question, leaving them to seek recourse against each other. This joint and several liability, known as in solidum, allows the project owner to maximise their chances of obtaining compensation, particularly when one of the parties is in default or insolvent.
In practice, if a defect results from both a design flaw and an execution flaw, the architect and the contractor may be joined in the action together. The court will then determine, in their internal relations, the share of liability attributable to each. But for the project owner, the priority is to obtain full compensation for the loss suffered, without having to arbitrate between the various stakeholders.

The Seller of a Building Completed Less Than Ten Years Ago

When the property has been acquired from a seller who had it built or had works carried out within the ten years preceding the sale, the purchaser benefits from a transfer of the legal warranties. This is known as the propter rem effect of construction warranties: they are attached to the works and not to the person who had them built. The purchaser may therefore act directly against the original construction professionals, as the seller would have, within the legal time limits.
This rule is essential for purchasers of new properties or recently renovated properties. It allows them to benefit from legal protections without having to systematically go through the seller. It also implies, for the seller, an obligation of transparency: at the time of sale, they must in principle provide the purchaser with the elements enabling the identification of the relevant construction professionals and insurers (acceptance protocol, insurance certificates, contracts, invoices).

The Off-Plan Seller and the Real Estate Developer

In the context of an off-plan sale (vente en l’état futur d’achèvement, VEFA), particularly common for the acquisition of new dwellings, the purchaser benefits from an additional point of contact: the seller, who assumes specific liability in their capacity as a construction professional within the meaning of Article 1792-1 of the French Civil Code. The developer or the off-plan seller is thus subject to the same warranties as the contractors and architects who actually carried out the works.
This liability of the off-plan seller is valuable, as it often simplifies the purchaser’s procedures. Rather than having to identify each stakeholder involved in the operation, the purchaser may act directly against the developer, who in turn seeks recourse against subcontractors or relevant companies. This is a common scheme in large-scale real estate operations, where the purchaser often does not know the precise identity of the companies that carried out the works.

The Technical Inspector and the Health and Safety Coordinator

For certain construction projects, particularly those of a certain scale or presenting specific risks, the involvement of a technical inspector (contrôleur technique) is mandatory. This professional, commissioned by the project owner, is responsible for verifying the compliance of the works with certain technical rules and preventing risks that may affect its solidity. Their liability may be engaged on the basis of Articles 1792 et seq. of the French Civil Code, strictly within the limits of the assignment entrusted to them.
Similarly, the Health and Safety Protection Coordinator (CSPS), although their mission is mainly preventive, may have their liability sought in certain situations. These specialised stakeholders complement the panel of persons potentially liable for a defect, and their inclusion in proceedings may prove relevant in technically complex matters, particularly where a control failure could have prevented or limited the defect.

The Subcontractor

The subcontractor, bound by contract to the principal contractor, is not in principle a direct debtor of the legal warranties towards the project owner. However, their liability may be sought on the basis of tort liability, particularly in the case of characterised fault. This possibility is important in practice, especially when the principal company is in default or insolvent. The project owner may then attempt to engage the liability of the subcontractor directly, provided that they can demonstrate the fault committed and the causal link with the observed defect.

Damage Insurance: An Essential Lever for Claimants

A Statutory Obligation Too Often Overlooked

The damage insurance (assurance dommages-ouvrage), provided for in Article L. 242-1 of the French Insurance Code, constitutes one of the pillars of protection for project owners and purchasers. It must, in principle, be taken out by any person commissioning construction works subject to the decennial warranty, and must be in place before the start of the works. It then accompanies the building throughout the duration of the decennial warranty and benefits successive owners.
The mechanism is particularly advantageous for the claimant. The damage insurance is referred to as a « pre-financing » policy: it is intended to compensate the claimant rapidly, without waiting for the determination of liability between the various parties. Concretely, the damage insurer must take a position on coverage within sixty days and present a compensation offer within ninety days from the date of claim notification.
This speed transforms the dynamics of the case. Rather than waiting for the sometimes distant outcome of court-ordered expertise or proceedings against the construction professionals, the claimant may obtain swift compensation, enabling them to finance repair works. The damage insurer then exercises, in place of the insured, subrogated recourse actions against the construction professionals and their decennial liability insurers. The insurer thus bears the burden of the recovery procedure, which is a considerable relief for the claimant.

Case Study No. 5 — Filing a Claim with the Damage Insurer
A couple acquires in 2019 a new house built by a single-family home developer. In 2023, structural cracks appear on the load-bearing walls of the ground floor. The couple notes that the floor shows signs of subsidence and that some doors no longer close properly.
Aware of the urgency, the couple sends to the damage insurer (taken out at the time of construction) a claim notification by registered letter with acknowledgement of receipt, attaching photographs, the acceptance protocol, the construction contract, and a private expert report. Within sixty days, the insurer commissions an adversarial expert assessment and notifies its acceptance of coverage under the decennial warranty.
Within ninety days following the claim notification, the insurer presents a compensation offer of €230,000 to finance the repair works. The couple accepts the offer, has the works carried out, and remains fully protected. The damage insurer then exercises its subrogated recourse against the decennial liability insurer of the home developer.
Lesson: damage insurance is a decisive lever. It allows for swift compensation, without waiting for the outcome of proceedings against the construction professionals. Strict compliance with claim notification formalities is essential to benefit from this protection.

The Absence of Damage Insurance: A Major Risk Too Often Underestimated

Despite its mandatory nature, damage insurance is not systematically taken out, particularly for small works or single-family home constructions carried out without recourse to a structured professional. Some individuals, building themselves or through isolated craftsmen, forgo this insurance for cost reasons. This apparent saving may prove catastrophic in the event of a claim.
The absence of insurance does not deprive the project owner of their rights against construction professionals, but it considerably complicates the procedures: action must then be taken directly against the contractors and their decennial liability insurers, with often longer time frames and sometimes more burdensome procedures. If the construction professionals are in default or uninsured, the claimant may find themselves without effective recourse.
For purchasers of existing properties, it is therefore essential, at the time of sale, to verify the existence and validity of the damage insurance. This verification must be a systematic point of attention in any transaction involving a property completed less than ten years ago. Otherwise, the purchaser may find themselves deprived of a valuable lever in the event of subsequent defects. The instrumenting notary has, on this point, an obligation of information that must be carefully observed when drafting the deed.

Case Study No. 6 — Buying a House without Damage Insurance: A Common Trap
A purchaser buys in 2022 a house built four years earlier by the previous owners, who had the works carried out by a group of craftsmen, without taking out damage insurance. The notary mentions in the deed the absence of this insurance, but the purchaser, unaware of the consequences, signs without concern.
Two years after the acquisition, massive infiltration appears through the roof, clearly linked to a defective installation of the roofing. The purchaser wishes to file a damage insurance claim: they then discover that no insurance was ever taken out. They must therefore act directly against the original roofer, who has since ceased activity, and against their decennial liability insurer, whose identification proves long and complex.
The proceedings take more than two years, where a damage insurance claim would have allowed pre-financing within a few months. The purchaser must advance part of the expert fees and bear the inconveniences linked to the persistence of the infiltration.
Lesson: the absence of damage insurance must be a major warning signal when purchasing a property completed less than ten years ago. Before buying, it is essential to require the production of this certificate and, failing that, to fully assess the risks incurred.

Articulation with Other Warranties

Damage insurance covers defects falling under the decennial warranty. It does not, in principle, apply to defects falling under the warranty of perfect completion or the two-year warranty, which must be addressed directly with the relevant companies. This distinction is important as it determines the choice of the party to contact in the event of a defect.
In practice, some damage insurance contracts include warranty extensions that also cover defects falling under the warranty of proper functioning, or even consequential intangible damages (rental losses, relocation costs). It is therefore advisable to carefully review the policy taken out to identify the exact extent of coverage and, where applicable, invoke these extensions when they exist.

The Course of Action to Follow When a Defect Arises in a Recent Building

Documenting and Recording the Defect Promptly

When a defect appears in a recent building, the first step is to document it rigorously. This involves taking dated photographs, precisely describing the defect, its location, the date of its appearance and any subsequent evolution. This initial documentation is precious: it will later allow demonstration that the defect appeared during the warranty period and was not aggravated by lack of maintenance or abnormal use.
In some cases, it may be useful to promptly engage a judicial commissioner (commissaire de justice, formerly known as huissier) to establish a formal record (constat). This step has the advantage of capturing the situation at a given moment, with particular evidentiary force. The formal record is particularly recommended when the defect is likely to evolve rapidly, when repair works are envisaged in the short term, or when a dispute with the construction professionals is anticipated.
Take the concrete example of a purchaser who discovers, two years after buying their new flat, significant cracks on the rear façade. Before any approach to the developer, they take time-stamped photographs, keep the acceptance protocol of the property, gather commercial and technical documents related to the operation, and commission a formal record by a judicial commissioner. A few weeks later, when the case is opened with the damage insurer, these elements will constitute the factual foundation of the file and greatly facilitate coverage.

Filing a Claim with the Damage Insurer

When the defect appears likely to fall under the decennial warranty, filing a claim with the damage insurer is generally the most effective avenue. The notification must be made by registered letter with acknowledgement of receipt and contain a precise description of the defect, its consequences and the contact details of the known stakeholders. It is useful to attach all documents already gathered: photos, reports, quotes, written exchanges.
Once the claim is filed, the insurer has sixty days to notify its decision on coverage, after an expert assessment carried out at its expense. If coverage is granted, it must present a compensation offer within an additional thirty days. Compliance with these time limits is governed by law and exceeding them allows the insured, after formal notice, to start the works and obtain reimbursement of the sums advanced with statutory increases.
In practice, it is recommended to pay close attention to the conduct of the expert assessment organised by the insurer. The claimant may, and often has an interest in, being assisted by a private expert or a lawyer during the expert proceedings. This assistance allows them to defend a technical reading of the file favourable to the claimant, to discuss the proposals of the insurer’s expert, and to ask the right questions about the origin of the defect and the extent of the necessary repairs.

Taking Direct Action Against the Construction Professionals

When the damage insurer refuses coverage, when the defects do not fall under the decennial warranty, or when no insurance was taken out, action must be taken directly against the construction professionals. This step begins in principle with a formal notice sent by registered letter with acknowledgement of receipt, in which the project owner or purchaser sets out the defect, requests its repair, and invites the construction professional to file a claim with their decennial liability insurer.
This formal notice has several virtues. It formally engages the construction professional, requires them to take a position, and allows the mobilisation of their decennial liability insurer, who must in principle be informed promptly. It also marks a useful stage in the chronology of the case, demonstrating that the project owner has acted with seriousness and method. It thus contributes to building a solid court file should the amicable route fail.
In the event of refusal or absence of response, court action will need to be considered, most often preceded by a request for court-ordered expertise. This expertise, ordered by the summary proceedings judge (juge des référés), allows the appointment of an independent expert whose mission is to analyse the defects, determine their origin, identify liability, and quantify the necessary repairs.

Court-Ordered Expertise: Often a Decisive Tool

Court-ordered expertise constitutes, in the majority of defect cases, an unavoidable stage. It introduces an independent technical perspective into the debate, which will be one of the principal elements considered by the trial judge. During expert proceedings, all parties are summoned: project owner, construction professionals, insurers, sometimes subcontractors. Each may submit observations, produce documents, and discuss the expert’s analyses on a contradictory basis.
This phase, which may extend over several months or even years in the most complex matters, is often decisive. It is during the expert assessment that positions are built and liabilities revealed. A well-prepared file, with clear formal records, photographs, technical documents, and structured argumentation, gives the claimant every chance to assert their rights. Conversely, an insufficiently constructed file may lead to an unfavourable expert report, the conclusions of which will then be difficult to challenge before the trial judge.

Time Limits to Comply With: A Constant Vigilance

Short Time Limits That Are Unforgiving

One of the most delicate aspects of construction defect litigation is compliance with time limits. Each warranty has its own expiration deadline, and exceeding these deadlines results in the definitive loss of the right to act. This rigour requires constant vigilance from the project owner.
The warranty of perfect completion must be invoked within the year following acceptance. The two-year warranty applies for two years from acceptance. The decennial warranty, finally, expires ten years after acceptance. But beware: these are deadlines for the extinction of the warranty, not merely limitation periods. To interrupt the limitation, court action must be initiated or written acknowledgement obtained from the construction professional. A simple letter, even registered, is not always sufficient to interrupt the period.
This is why, as soon as a defect is observed and no amicable settlement quickly emerges, it is advisable to refer the matter to the summary proceedings judge for an expert assessment. This action has the effect of interrupting the period throughout the duration of the expert proceedings and thus preserves the possibility of bringing substantive action. This is an essential precaution, particularly when the defect appears in the final year of the decennial period.

Articulation with Ordinary Limitation

For defects that do not fall under the special legal warranties — for example, apparent defects not reserved at acceptance, or purely contractual breaches —, ordinary limitation applies. The period is, in principle, five years from the day on which the holder of the right knew or ought to have known the facts enabling them to exercise their action. This limitation, more flexible than the deadlines of the legal warranties, must nevertheless not be neglected.

Identifying and Quantifying Compensable Damages

The Cost of Repair Works

The principal item of compensation is generally the cost of repair works. This corresponds to the amount required to bring the property back into the condition originally provided for. This cost must be quantified precisely, generally on the basis of detailed quotes or the conclusions of the expert assessment. When the repair works involve removing and reinstalling elements not affected by the defect (for example, removing a floor covering to access defective pipes), these costs also fall within the scope of compensation.

Ancillary Damages

Beyond the purely technical costs, numerous ancillary damages may be claimed. These include relocation costs during the works, moving and storage costs, rental losses when the property is intended for letting, the loss of enjoyment linked to the inability to use the property normally, the costs of assistance from a private expert or project manager for monitoring the repair works, and financial costs linked to delivery delays.
In some cases, the project owner may also obtain compensation for moral prejudice, where the situation has caused particularly significant distress. This item of damage is, however, more difficult to quantify and generally requires a circumstantial demonstration of the personal and psychological consequences suffered.

Intangible Losses for Investors

When the property has an economic purpose — rental property, commercial premises, investment building —, intangible losses may represent a significant share of the overall damage. Lost rents, decline in market value, lost commercial opportunity, indemnities paid to tenants: these items must be documented rigorously and supported by objective elements (previous leases, accounting attestations, real estate valuations, exchanges with tenants).

Case Study No. 7 — The Full Damage of a Real Estate Investor
A family-owned real estate investment company acquires in 2017 a building of four new dwellings under an off-plan sale, intended for letting. In 2023, defects in acoustic insulation are identified between the dwellings, making cohabitation difficult. Several tenants complain and one of them leaves the premises, invoking a breach of the obligation to deliver.
A court-ordered expert assessment confirms an execution defect that renders the building unfit for its purpose as collective housing (minimum acoustic standards are not met). The investment company obtains in court compensation covering: the acoustic insulation repair works (€110,000), the rental losses suffered during the works (€35,000), the indemnities paid to the tenant who left the premises (€8,000), the lawyer’s fees and private expert costs (€12,000), and the temporary depreciation of the building.
Lesson: for an investor, compensation is not limited to the technical cost of repair. Building a complete file requires integrating all the economic losses linked to the defect, supported by precise and quantified documentary evidence.

Frequently Asked Questions from Individuals and Investors

What Should You Do if the Construction Professional Has Disappeared or Become Insolvent?

This is one of the most frequent situations in practice. When the company has been the subject of a judicial liquidation, has ceased its activity, or has simply disappeared, direct action against it becomes illusory. But this does not mean that the project owner is without remedy. The default of the construction professional is precisely one of the situations for which the insurance system was designed.
If damage insurance has been taken out, the claim notification procedure may be initiated without difficulty, with the insurer intervening as pre-financing. Furthermore, the decennial liability insurer of the defaulting construction professional may be directly engaged by the project owner, who has a direct right of action against them. However, the relevant insurer must first be identified, which may require going back to the original contractual documents, contacting professional authorities, or obtaining disclosure of insurance policies through court proceedings.
What Happens in the Event of Resale of the Property During the Warranty Period?
As mentioned previously, the legal warranties are attached to the works and not to the person. The purchaser of a property completed less than ten years ago therefore benefits from the warranties initially taken out. This transmission occurs automatically, without the need for any specific formality. However, it is strongly advised, at the time of sale, to recover from the seller all the technical, contractual and insurance documents (acceptance protocol, damage insurance and decennial liability certificates, construction contracts, plans). Without these documents, invoking the warranties becomes considerably more difficult.

Does the Real Estate Diagnostic Report Provided at the Sale Protect the Purchaser?

The mandatory diagnostic reports provided at the sale of a property (asbestos, lead, termites, energy performance, etc.) have an informational function, but do not cover all defects likely to affect a recent building. They in no way replace the legal warranties of construction. A purchaser who finds, after the sale, a defect falling under the decennial warranty may therefore exercise their remedies independently of the content of the diagnostic reports, which are not intended to flag this type of issue.

Can You Take Action if the Defect Was Already Visible at Acceptance?

This is a point that is often misunderstood. When the defect was apparent at the time of acceptance, the project owner must in principle have made a reservation in the acceptance protocol. Failing this, they are deemed to have accepted the works in their current state. The decennial warranty covers, in principle, only defects hidden at acceptance or those that emerge subsequently. This is why acceptance is an essential act, which must receive particular attention. It is strongly recommended to carry out a thorough inspection, ideally accompanied by a building professional, before signing the acceptance protocol.
What Should You Do if Several Companies Were Involved and the Origin of the Defect Is Uncertain?
This is a frequent situation. When a defect may result from the involvement of several companies or a combination of several causes, it is generally advisable to engage all potentially relevant stakeholders. The court-ordered expert assessment will then determine the share of liability of each. This broad inclusion protects the interests of the project owner and prevents the proceedings from being slowed down by late third-party joinders or by certain liable parties being released from liability through limitation.

Are Aesthetic Defects Covered by the Legal Warranties?

Purely aesthetic defects do not generally fall under the decennial warranty, which requires an impact on solidity or fitness for purpose. They may, however, be covered by the warranty of perfect completion during the first year. Beyond that period, their coverage will depend on contractual provisions and the ability to demonstrate fault on the part of the construction professional. A minor aesthetic defect (variation in tone, imperfect finishes) will be more difficult to claim than a major aesthetic defect significantly affecting the appearance of the property.

What Should You Do if the Developer Disputes the Qualification of the Defect?

It is common for the developer or its insurer to dispute the decennial qualification of a defect, arguing that it is an aesthetic flaw or an intermediate defect that does not compromise either the solidity or the fitness for purpose of the property. In these situations, court-ordered expertise is generally the most effective means of settling the qualification. The lawyer plays an essential role in formulating the expert’s mission and in defending the decennial qualification throughout the proceedings.

Practical Advice for Securing Your Position

Keeping All Construction or Acquisition Documents

One of the most important pieces of advice, but also the simplest, is to meticulously keep all documents relating to the construction or acquisition. This includes the original contract, addenda, acceptance protocols, damage insurance and decennial liability certificates, invoices, technical specifications, plans, construction reports, certificates of compliance, and written exchanges with the stakeholders. These documents constitute the indispensable foundation of any litigation file.
For a purchaser of an off-plan property or from a single-family home developer, it is particularly useful to set up a dedicated file for the operation, kept for the entire duration of the legal warranties — that is, at least ten years after acceptance. This precaution, often overlooked in the early years following delivery, may prove decisive when a late defect emerges. It is recommended to centralise these documents in both paper and digital format, ideally with an external backup.

Reacting Promptly to the First Signs of Defect

Many defects appear progressively: a crack that widens, a damp patch that spreads, a malfunction that worsens. The temptation to wait is strong, hoping that the problem will resolve itself or waiting to gather sufficient evidence to act. This wait is generally counterproductive. The older the defect, the more difficult it becomes to demonstrate its origin and identify precisely the moment of its appearance.
Reacting promptly, from the first signs, has several advantages: preservation of warranty deadlines, ease of proof, ability to limit the worsening of the defects, and capacity to mobilise insurance effectively. A simple letter sent to the construction professional or insurer in the first weeks following the observation of the defect may be enough to trigger favourable dynamics.

Not Carrying Out Repair Works Without Precaution

When the defect is observed, the temptation is great, particularly if the situation makes the property uninhabitable, to quickly carry out repair works. This haste may, however, compromise the rest of the case. Repair works often erase the evidence of the original defect and make it more difficult to demonstrate the origin of the problem. Insurers and judges are, by principle, particularly attentive to this point: repairs carried out without prior consultation may undermine coverage.
The right reflex is, before any intervention, to capture the situation through photographs, a judicial commissioner’s record, or a private expert assessment, and to inform the relevant parties (construction professionals, insurers) of the need to intervene. If the situation is urgent, conservatory works may be undertaken in agreement with the damage insurer, who may agree to finance emergency measures pending the final settlement of the claim.

Seeking Support at the First Difficulties

Construction defect litigation is probably one of the most technical fields of real estate law. It combines precise legal rules, complex technical concepts, insurance issues, and specific procedures. The temptation is sometimes to handle the initial steps alone, telling oneself that one will see a lawyer « if things get complicated ». This approach is understandable but often regrettable.
Engaging a lawyer specialised in construction law from the very first difficulties has several advantages: precise legal qualification of the defect, optimal choice of actions to bring, drafting of effective written submissions, assistance during expert proceedings, anticipation of opposing arguments, articulation between the various procedures. This upstream involvement is generally more effective, and often less costly in the long run, than late involvement when the situation has deteriorated.
The same applies to real estate investors, who are sometimes confronted with defects affecting let or to-be-let properties. In this context, the financial stakes can be considerable, between rental losses, additional costs, and the decline in the property’s market value. Professional support allows the optimisation of the defence of patrimonial interests and the securing of an operation which, in the absence of an appropriate response, may durably degrade the profitability of the real estate project.

When to Consult a Lawyer in Real Estate and Construction Law?

Several situations should lead to a prompt consultation with a specialised lawyer. This is particularly the case when a significant defect is observed in a recent building, when amicable steps fail to produce results within reasonable time frames, when the damage insurer delays its position or refuses coverage, when several stakeholders are involved and liability is disputed, or when the expiration of a warranty deadline is approaching.
The lawyer can analyse the situation in light of the various liability regimes, identify the right contacts, draft the necessary correspondence, initiate appropriate proceedings (summary proceedings for expertise, substantive action, action against insurers), assist their client during expert proceedings, negotiate with opposing parties, and bring the case before the competent courts where appropriate.
For individuals, the stake is often personal and patrimonial: having the loss suffered recognised, obtaining the restoration of the property, and preserving their investment. For investors, the stakes are also economic and operational: maintaining the profitability of an operation, limiting the impact of defects on the real estate portfolio, and securing relations with tenants. In all cases, a professional and structured approach is generally the best guarantee of a favourable outcome.

Effective Protection — Provided It Is Activated in Time

French law offers, in matters of defects affecting a recent building, one of the most protective frameworks in the world. The combination of legal warranties (perfect completion, two-year, decennial), the mandatory insurance system (damage insurance and decennial liability), and the joint and several liability of construction professionals allows, in the vast majority of situations, the obtaining of effective compensation for the losses suffered. But this protection is fully effective only if it is mobilised in time, with method and rigour.
Observing a defect is only the first step. It must then be legally qualified, the liable parties identified, the right procedural vehicle chosen, the insurance mobilised, the evidence preserved, and the deadlines respected. This approach, which may seem daunting, becomes much more accessible with appropriate professional support.
Experience shows that the best-managed cases are those that benefit, from the appearance of the defect, from rigorous legal analysis and an overall strategy articulating the various levers available. Conversely, cases handled in a fragmented or late manner often lead to disappointing results, even though the rights of the claimant were perfectly well-founded.
When faced with a defect affecting a recent building, the best attitude is therefore not to underestimate the situation, to document the facts rigorously, to comply with the deadlines, and to surround oneself promptly with the necessary advice. It is this combination of responsiveness, method, and support that allows the transformation of a potentially worrying situation into a controlled file, in which the rights of the project owner or purchaser may be fully exercised.

Defects in a new building, structural cracks, water infiltration, defective workmanship, waterproofing issues or acoustic problems: these are all situations in which a rigorous analysis of your file and a tailored legal strategy can make all the difference. The earlier you act, the greater your chances of obtaining full and prompt compensation.