Contractor dispute in Belgium: formal notice, acceptance and liability

Poor workmanship, endless delays, unexpected charges for extra work or a contractor who simply stops turning up: a contractor dispute is one of the most expensive conflicts a private individual can face. The order in which you take each step often determines whether you recover your money and your building site. This article covers the formal notice, the expert assessment, your claims, the acceptance of the works and the various forms of contractor liability under Belgian law.

The specific rules on construction contracts (aanneming van werk / contrat d’entreprise) are found in the old Civil Code (Articles 1787 et seq.). For contracts concluded on or after 1 January 2023, the general rules of Book 5 of the new Civil Code on obligations also apply, in particular those on termination and damages. A new Book 7 of the Civil Code, enacted by the Act of 22 July 2026 and published in the Belgian Official Gazette (Belgisch Staatsblad / Moniteur belge) on 23 September 2026, reforms the rules on construction contracts. That Book enters into force on 1 September 2027, the first day of the twelfth month after its publication (Article 50 of that Act); until then, the current rules continue to apply. It applies to legal acts and facts occurring after that date; for the future effects of construction contracts concluded earlier, the previous rules continue to apply unless the parties agree otherwise (Article 49).

Step 1: give your contractor formal notice

Send a formal notice (ingebrekestelling / mise en demeure) by registered post, listing the defects or failings in concrete terms and setting a reasonable deadline to remedy them. This establishes what you are complaining about and when you did so. Our article on the formal notice explains how to draft such a letter correctly.

Do not simply stop all payments: withholding everything can backfire on you. Withholding an amount in proportion to the seriousness of the failings is, as a rule, defensible. Also keep all correspondence, invoices, specifications and plans: in a construction dispute, much is decided on the basis of what is on paper.

Step 2: secure the evidence

For serious or technical defects, an assessment carried out in the presence of both parties is crucial: an amicable expert assessment attended by both sides, or an expert appointed by the court (Articles 962 et seq. of the Judicial Code), if necessary in summary proceedings (kort geding / référé). Anyone who first has a third party carry out repairs and only then goes to court often destroys their own evidence. If urgent work is needed, document everything thoroughly with photographs and an official report drawn up by a bailiff (gerechtsdeurwaarder / huissier de justice).

Also check whether you have legal expenses insurance: it may cover all or part of the costs of the expert assessment and of your lawyer. If so, report the dispute to your insurer as soon as possible.

Step 3: what can you claim?

Depending on the circumstances, you can claim:

• performance of the works, if necessary subject to a penalty payment (dwangsom / astreinte);
• authorisation to have the works carried out by another contractor at the expense of the defaulting contractor;
• a price reduction or damages;
• termination of the contract, with damages;
• the delay penalties provided for in the contract.

For contracts concluded on or after 1 January 2023, in the event of a serious breach you can also terminate the contract out of court, by written notification to the contractor, as a rule after a formal notice. You do so at your own risk, however: if the court later finds that the breach was not serious enough, you will be the party in breach. Our article on breach of contract explains these remedies in more detail.

Acceptance of the works: do not sign blindly

Acceptance (oplevering / réception) usually takes place in two stages. Provisional acceptance records that the works have been completed; final acceptance follows after a guarantee period set by the contract. Which of the two counts as approval of the works (aanvaarding / agréation) depends first and foremost on the contract. Often the contractor is already discharged from visible defects at provisional acceptance, except those you expressly ask to have repaired.

Anything you accept without reservation will be difficult to challenge later, because approval covers visible defects. List all your comments in full in the acceptance report and make payment of the balance conditional on the repairs. If in doubt, have an architect or an independent expert assist you at the acceptance.

Ten-year liability of the contractor and the architect

For serious defects that endanger the solidity or stability of the building or of an important part of it, the contractor and the architect are liable for ten years (Articles 1792 and 2270 of the old Civil Code). That period runs from the approval of the works. This liability is a matter of public policy, so it cannot be excluded or limited by contract.

According to the Court of Cassation, this ten-year period is a strict time bar (vervaltermijn / délai de déchéance): the claim must be brought before the court within it. A registered letter or ongoing negotiations are, as a rule, not sufficient. So do not wait until the final year to take action.

Compulsory insurance

Since 1 July 2018, contractors, architects and other construction service providers must insure their ten-year liability for homes for which the involvement of an architect is compulsory and for which the final planning permission (stedenbouwkundige vergunning / permis d’urbanisme) was issued after that date (Act of 31 May 2017). The insurance covers the solidity, stability and watertightness of the closed shell (gesloten ruwbouw / gros œuvre fermé), insofar as a lack of watertightness endangers solidity or stability. Ask for the insurance certificate before the works start; the contractor is required to provide it. This insurance is particularly important if the contractor has since gone bankrupt or ceased trading.

Minor hidden defects

Defects that were not visible at the time of approval and do not affect the solidity of the building are not covered by ten-year liability. The contractor may still be liable for them, but you must bring the claim within a reasonable time after discovering the defect, and no later than ten years after approval. Unlike a manufacturer or specialised seller, a contractor is not presumed to know of the defect: you must prove fault on the contractor’s part.

The contract may limit this liability within certain bounds, but never for intentional misconduct. Where the client is a consumer, the rules on unfair contract terms in the Code of Economic Law also apply.

Extra work: what can the contractor charge?

Where a fixed price has been agreed for a building according to an agreed plan, the contractor cannot claim a price increase for changes or extensions unless they were authorised in writing and their price was agreed with the client (Article 1793 of the old Civil Code). Contest unrequested extras in writing straight away, and record every order for extra work in writing yourself, including the price.

Terminating the contract with your contractor

The client may terminate a fixed-price construction contract unilaterally, even after the work has begun, provided they compensate the contractor for all expenses, all work done and the profit the contractor could have made (Article 1794 of the old Civil Code). That route is expensive. In the event of a serious breach by the contractor, termination of the contract for breach, after formal notice, is often the better choice.

Building a home: the Breyne Act

If you are having a home built, or are buying a home off-plan or under construction, and you must pay before completion, the mandatory protective rules of the Breyne Act (Act of 9 July 1971) apply. They govern, among other things, staged payments according to the progress of the works, guarantees and acceptance. A contract that departs from these rules often gives the buyer or client strong arguments. Whether your contract falls under the Breyne Act must be assessed case by case.

Frequently asked questions

My contractor has gone bankrupt. What now?

File your claim through the central Regsol register, within the time limit set in the bankruptcy judgment. Check which guarantees and insurance policies can be called upon, and have the state of the site recorded in the presence of both parties before another contractor continues the work. Our article on filing a claim in a bankruptcy explains more.

Which court has jurisdiction over a dispute with my contractor?

That depends on the amount of your claim and on the capacity in which you act. Claims up to EUR 5,000 generally go to the justice of the peace (vrederechter / juge de paix) under Article 590 of the Judicial Code. For larger claims, a private individual suing a contractor that is a business can, as a rule, choose between the court of first instance and the enterprise court (ondernemingsrechtbank / tribunal de l’entreprise) under Article 573, second paragraph, of the Judicial Code; between two businesses, the enterprise court has jurisdiction.

Can I bring in another contractor myself to finish the works?

Not without precautions. First have the state of the works recorded in the presence of both parties and give the contractor formal notice. Having the works carried out by a third party at the contractor’s expense generally requires authorisation from the court or a clause in the contract. For contracts concluded on or after 1 January 2023, in urgent cases or other exceptional circumstances, and after having the failure properly recorded, you may replace the contractor without prior authorisation by written notice, but at your own risk (Article 5.85 of the Civil Code).

How long does a construction case take?

With a court-appointed expert, proceedings can easily take one to several years. A negotiated solution after the expert assessment is often quicker and more certain.

Novex Advocaten: your lawyer in a contractor dispute

We assist clients in disputes with contractors and architects, from the formal notice and acceptance to the expert assessment and court proceedings. See also our articles on hidden defects after buying a home and on damage caused by building work next door.

Call 0484 99 22 72 or email asfour@novexadvocaten.be, preferably before making any further payments.