In Belgium

A construction defect (vice de construction / bouwgebrek) is a fault in the design, materials or execution of building works that compromises the stability, solidity or structural integrity of the building. Under Belgian law, architects and contractors bear a special ten-year liability (decennial liability) for such defects.

Legal basis. Articles 1792 and 2270 of the Civil Code establish decennial liability. This is a public order provision — it cannot be contractually excluded.

Scope. Decennial liability covers only “serious” defects: those affecting the building’s stability (foundation cracks, structural walls, roof structure) or making it unfit for its intended purpose. Cosmetic or minor defects fall under the general warranty for hidden defects.

How it works

Who is liable? The architect and the contractor are jointly and severally liable. The owner can pursue either or both.

Timeline. The 10-year period starts from the definitive acceptance of works (not provisional acceptance). The claim must be filed before the 10-year period expires.

Proof. An expert report is almost always necessary to establish that the defect affects structural integrity and to identify the responsible party.

Relevance for landlords. If a rented property has a construction defect, the landlord is liable to the tenant for disturbance of enjoyment and repairs. The landlord can then exercise recourse against the architect or contractor under decennial liability.

Insurance. Since 2018, the Peeters-Borsus Act (1 July 2018) requires architects and contractors to hold decennial liability insurance for residential buildings. This ensures funds are available to cover claims.

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Good to know
The mandatory decennial liability insurance (since 2018) only covers the building’s closed shell (structure, waterproofing). Interior finishing works, technical installations and landscaping are not covered. Landlords should verify what their contractor’s insurance actually covers before works begin.

Practical example

Five years after construction, cracks appear in the load-bearing walls of a rented apartment. The tenant notifies the landlord, who commissions an expert report. The expert confirms a foundation design error. The landlord repairs the property (cost: 35,000 EUR) and files a claim against the architect and contractor. The court holds both liable under decennial liability. The contractor’s insurer covers the repair costs through subrogation.