Buying off-plan —or purchasing a property under construction— appeals to many Belgians looking to acquire a new, customizable home that complies with current standards. However, this type of purchase carries specific risks. To regulate them, Belgium has implemented a special legal framework: the Breyne Law of July 9, 1971.
Although this law provides substantial protection to buyers, certain pitfalls remain. This article will help you better understand how to secure your real estate project.

The Breyne Law: Scope of Application
The Breyne Law applies to sales of buildings under construction or to be constructed, provided the following conditions are met:
- The property is primarily intended for residential use (main or secondary residence);
- The seller undertakes to deliver a completed property;
- The buyer is not in the business of acquiring off-plan properties for resale;
- The contract provides for staggered payments in line with construction progress.
First step: Check that your contract meets the above conditions and explicitly states that it falls under the Breyne Law. If not, you may not benefit from any of the protections provided.

Down Payments: No More Than 5% Before the Notarial Act
The law strictly limits the down payments a developer can request: a maximum of 5% of the total price before the authentic deed is signed.
However, certain abusive practices persist:
- Requests disguised as “reservation fees” or “preliminary studies”;
- Pressure to pay a larger amount quickly.
Regardless of the label, any advance payment is legally considered a down payment subject to this 5% limit. Always request a dated and signed receipt for each payment.
Staggered Payments: Proportionality Required
Payments must match the actual progress of the construction site. While the law doesn’t mandate a specific schedule, it enforces strict proportionality.
A common payment schedule looks like this:
- 5% upon signing the contract;
- 15% at the notarial act;
- 25% upon completion of foundations;
- 25% upon completion of the closed shell;
- 15% upon completion of technical installations (heating, electricity, etc.);
- 10% at the end of screeding and plastering;
- 5% at provisional acceptance.
Reject any schedule that requires you to pay more than what has been built. If necessary, have an independent architect assess the compliance of the timeline.
Completion Guarantee: Your Safety Net
Before any payment, the developer must provide a completion or refund guarantee equal to 5% of the construction price.
This guarantee can take the form of:
- A bank guarantee;
- A deposited sum.
It protects you in case of bankruptcy or abandonment of the project.
Be cautious of developers who provide the guarantee late or offer ambiguous forms (letters of intent, non-binding bank attestations, etc.). Also verify whether the developer is certified, as non-certified developers must provide a 100% guarantee of the construction price.

Delivery Deadlines: Avoid Vague Promises
The contract must set a start date for construction and a total execution deadline.
Beware of clauses invoking “exceptional circumstances” or “force majeure” without clear definitions. These vague formulations can sometimes be used by developers to justify any delay.
Demand clear deadlines and, most importantly, verify that contractual late penalties are included — they should at least match the standard rental value of the completed property.
Project Changes: Watch Out for Unexpected Costs
The contract must specify under what conditions the developer can change materials, equipment, or plans.
Be wary of phrases like “or equivalent,” which can authorize changes that reduce quality.
Any significant change must include:
- Your written approval;
- A clear estimate of any additional costs.
Provisional Acceptance: Don’t Sign Lightly
Provisional acceptance triggers the warranty period (one year until final acceptance). It’s a decisive step.
Before signing:
- Inspect the property thoroughly, ideally with an independent expert;
- Record all defects in writing in the inspection report;
- Do not accept if major defects exist.
Final acceptance occurs one year later. That’s your last chance to report uncorrected visible defects.

Additional Costs: Demand Transparency
Some costs can significantly increase the final bill:
- Utility connections (water, gas, electricity, telecom);
- Exterior works;
- Administrative fees, notary fees, VAT, etc.
Request a complete, written breakdown of all additional costs before signing.
Conclusion: Seek Professional Guidance
Buying off-plan remains a complex undertaking. Even under the Breyne Law, disputes are common: delays, defects, missing guarantees, cost overruns…
Specialized legal support helps you verify contract validity and compliance, anticipate contractual pitfalls, and respond effectively in case of conflict with the developer or builder.

With decades of experience in the field, Vanbelle Law Boutique is available to analyse your off-plan purchase projects, assist you throughout the process, and defend your interests.
Don’t let legal intricacies derail your real estate project. Better safe... with proper advice.