Belgian construction warranties: a three-tier system
In Belgium, construction law protects new-build buyers through a layered warranty system covering the building for 10 years after the provisional reception. This system, inherited from the Napoleonic Civil Code and thoroughly reshaped by the Act of 31 May 2017 on mandatory insurance (Belgian Official Gazette), rests on three complementary layers: the perfect-completion warranty (1 year), the two-year warranty and the ten-year liability.
To these three foundations are added, before reception, the Breyne Law completion guarantee (which secures the finishing of works if the developer goes bankrupt) and the all-risks construction insurance (which protects during the execution phase). Together, these mechanisms form a continuous chain of protection from contract signature to the tenth anniversary of reception.
Many buyers confuse these warranties or believe they are automatic. They are not all. Some are activated by a simple legal act (the reception minutes), others require a written declaration, formal notice or summons. Understanding who covers what, for how long, and how to activate the warranty is the condition for effectively defending your rights.
The perfect-completion warranty: 1 year of legal aftercare
The perfect-completion warranty is the first layer of protection after provisional reception. It is inspired by Article 1792-6 of the French Civil Code but applies in Belgium through contract law and case law.
Duration. One year from provisional reception. This deadline is strict: after one year, you can no longer invoke this warranty, even if you reported the defect in time but the contractor dragged their feet.
Coverage. All visible defects listed in the provisional reception minutes, plus the defects emerging through use during this first year. It is a broad warranty: paint, finishes, taps, electricity, equipment, compliance with specifications — anything that is not a structural defect falling under the ten-year liability.
Activation. Written notification to the contractor as soon as a defect is observed. No formal notice required at the start, but keep the written proof (e-mail, letter). If the contractor does not respond within 30 days, escalate to registered formal notice with acknowledgement of receipt.
Link to the 5% security deposit. The Breyne Law security deposit (5% of the price blocked at the notary) is the financial weapon of the perfect-completion warranty. At the final reception (one year after the provisional), the balance of the deposit is only released if all reservations are lifted. In case of blockage, the notary can retain the amount to finance third-party execution.
To go deeper: Perfect-completion warranty, Lifting reservations, Breyne Law security deposit.
The two-year warranty: 2 years for equipment items
The two-year warranty targets equipment items that can be removed or replaced without affecting the structure of the building.
Duration. Two years from provisional reception. It covers defects appearing during this period, even if they were not visible at reception.
Typical coverage.
- Water heater, boiler, heat pump, solar panels
- Taps and sanitary appliances
- Mechanical ventilation (VMC)
- Integrated appliances (oven, hob, built-in dishwasher)
- Blinds, motorised shutters, gate automations
- Cumulus, hot-water tanks, water softeners
Important limitations. The two-year warranty does not cover normal wear and tear nor defects due to poor maintenance. Keep manuals, commissioning certificates and maintenance proofs (annual boiler service, for instance). Without these, the contractor or manufacturer may invoke poor maintenance to refuse coverage.
Manufacturer’s commercial warranty. Often the manufacturer’s commercial warranty (1 to 5 years, sometimes 10 years for a top-end boiler) is more advantageous than the two-year. Activate it first, keep the two-year as a safety net.
Detailed cluster: Two-year warranty.
“Defects revealing themselves within two years after reception are covered by the two-year warranty insofar as they affect an equipment item separable from the shell.”
Liège Court, 14 March 2019, RGAR 2019, No. 15.621
The ten-year liability: 10 years for solidity
The ten-year liability is the longest and most powerful warranty in Belgian construction law. It weighs on the contractor and on the architect who designed or executed the weather-tight shell.
Duration. Ten years from provisional reception (Cass., 25 Oct. 1985; Cass., 18 Nov. 1983). This position is the consensus in Belgian doctrine, although a few isolated decisions start the period from final reception.
Coverage. The technical information notes published by Buildwise (formerly CSTC) serve as a reference for experts to characterise these defects, grouped in three categories engaging the ten-year liability:
- Defects compromising the solidity of the building (structural cracks, foundation subsidence, framing defects, load-bearing wall failure)
- Defects affecting an element indissociable from the shell (poorly executed roof weatherproofing, chronic infiltration through buried walls)
- Defects rendering the building unfit for its purpose (heating issues making the home uninhabitable, major acoustic insulation defect in a multi-unit building)
Who is liable? The main contractor (turnkey or general), the architect, and where applicable the engineering office. Their liability is joint and several: you can take action against one or the other, or both simultaneously. To dig deeper: Architect ten-year liability.
Mandatory ten-year insurance (Act of 31 May 2017). Since 1 July 2018, ten-year liability insurance is mandatory for all professionals working on the weather-tight shell of a dwelling. The certificate must be provided before the site begins. Direct action: since 2017, you can sue the insurer directly without going through the contractor, which is valuable in case of bankruptcy.
Pilot cluster: Ten-year liability and Apartment ten-year liability for properties in co-ownership.
All-risks construction insurance (TRC): before reception
The all-risks construction insurance protects during the construction phase, before provisional reception. It is optional for private buyers, but strongly recommended — and sometimes imposed by turnkey contracts or banks financing the project.
Scope. The TRC covers:
- Theft on the site (materials, tools, installed but not yet received equipment)
- Vandalism and malicious acts
- Water damage from wrong manipulation, frost, pipe burst
- Fire and consequences (smoke, fire-brigade intervention)
- Natural disasters (storm, hail, flood)
Who pays? Depending on the contract. In a turnkey arrangement, it is usually the developer who subscribes the TRC on their account. In a build with an independent architect, it is often the client who subscribes (cost: 0.15 to 0.4% of total price).
Link to the ten-year liability. The TRC stops at provisional reception; the ten-year liability takes over. There must be no grey area. Check the effective dates of both contracts.
Cluster: All-risks construction insurance.
The Breyne Law completion guarantee: the developer’s security
Under the Breyne Law, the developer must provide before signing a completion guarantee (Article 12) in two forms:
- Bank guarantee: a bank undertakes to finance the completion of works up to compliant delivery, in case of developer default
- Completion insurance: an insurer makes the same undertaking
What it is for. If your developer goes bankrupt mid-build, the completion guarantee finances the takeover by another contractor until delivery of the property in its contractual state. Without this guarantee, you risk paying twice and recovering an unfinished site.
How to verify. The completion certificate must be annexed to the contract. If it is missing, the contract is void. See our cluster Breyne Law completion guarantee and our pillar Breyne Law.
The architect’s ten-year liability
The architect is jointly liable with the contractor for 10 years for defects resulting from a design, control or supervision failure. This is a liability distinct from the contractor’s — the architect does not perform the works, but guarantees that plans, follow-up and coordination complied with industry rules.
Typical cases triggering the architect’s ten-year liability:
- Poorly dimensioned plans leading to siting defects
- Material choices unsuitable for soil or climate
- Lack of effective control of key phases (foundations, weatherproofing, framing)
- Non-compliance with the building permit issued
Certificate and insurance. Since 2007, ten-year liability insurance has been mandatory for architects (Act of 15 February 2006). Demand the certificate when signing the contract — without it, the architect cannot practice. See: Architect ten-year liability.
Activating a warranty: step-by-step procedure
Having a warranty is not enough — you need to know how to activate it in the forms and deadlines imposed by Belgian law.
Step 1 — Record the defect. Date, dated photos, written testimony if possible. Keep all material elements (broken samples, defective parts). A defect not recorded in time becomes legally difficult to prove.
Step 2 — Written notification to the contractor. Registered letter with acknowledgement of receipt detailing the defect, its location and date of appearance. This notification interrupts limitation. Keep the receipt for 10 years.
Step 3 — Amicable expert appraisal. Appoint a private expert to characterise the defect. Cost: €300 to €1,500 depending on complexity. The report will form the basis of any subsequent action. See our Defects expertise service.
Step 4 — Formal notice and negotiation. If the contractor does not respond, formal notice with deadline (15 to 30 days). Possibility of mediation or conciliation.
Step 5 — Legal action or direct action against the insurer. In case of amicable failure, summons before the business court. Since 2017, you can also sue the contractor’s ten-year insurer directly (new Article 1792-7).
For details: Contractor recourse, Contractor formal notice, Judicial construction expertise.
How to choose and activate your warranties wisely
Four reflexes to adopt from contract signature:
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Demand insurance certificates (contractor ten-year, architect ten-year, Breyne Law completion guarantee, TRC) before any work start. No certificate, no signature.
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Make exhaustive provisional reception minutes with an independent expert. Any reservation not listed is legally deemed accepted — so not covered by the perfect-completion warranty.
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Record every defect as it arises during the 10 years following reception. Build a file (dated photos, letters, invoices) that will serve if you need to invoke the ten-year liability in 5 or 8 years.
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Never wait until the last moment. Limitation periods are merciless. A defect discovered in year 9 must be notified and ideally summoned before the end of the ten-year period.
Conclusion
Belgian construction warranties form a coherent legal edifice, but their effectiveness depends entirely on the client’s rigour in their activation. The provisional reception minutes, written notifications, insurance certificates, maintenance proofs: all of this constitutes the legal capital that makes warranties actually effective.
Entrusting this work to an independent expert is rarely a luxury — it is often what makes the difference between a won dispute and a file lost on procedural grounds.