What's New For Belgian Construction Contracts Under The New Book 7 Of The Civil Code

What You Need to Know

Key takeaway #1

The proposal for a new Book 7 for the Belgian Civil Code contains important changes to the current risk allocation between employer and contractor, e.g., in the context of the management of other contractors, the cooperation between contractors, and the requirements for proper performance.

Key takeaway #2

Contractors will have a new right to renegotiate lump sum contracts if unforeseen issues arise from circumstances that existed prior to the signing of the contract. This is especially relevant when there are pre-existing soil conditions.

Key takeaway #3

The proposal is currently under review with the Belgian Council of State. The law is expected to enter into force in the course of 2026. As the reform will have a significant impact on construction contracts, clients are strongly advised to proactively review and revise their contracts and templates in light of the reform.

Contract Management Practices Update on Belgian Law in 2025

In recent years, there has been a wave of new legislation impacting contracts and contractual terms. The Belgian legislator is gradually adopting the different Books of the Belgian Civil Code, and the Belgian Code of Economic Law has been updated several times. These changes affect the way contract terms need to be drafted, not only between companies but also with consumers.

In this series of alerts, we provide guidance on the drafting and reviewing of standard contracts and contract terms. Our first alert emphasized the importance of drafting fair contract clauses, and our second alert focused on the abolition of the quasi-immunity for auxiliaries (such as directors and subcontractors, with the latter being particularly relevant for construction contracts) and the interaction between Book 6 of the Belgian Civil Code and B2B legislation on contract terms.

Our third alert gave an overview of the general changes in the new Book 7 of the Belgian Civil Code, and this fourth alert focuses specifically on the changes that Book 7 will impose on construction contracts.

Alert 4: What's new for Belgian Construction Contracts under the new Book 7 of the Civil Code

The proposed Book 7 aims to align Belgian special contract law with contemporary needs and international standards. The proposal is especially relevant for construction contracts. In general, construction contracts are entered into between an employer ('bouwheer' or 'le maître d'ouvrage') and a contractor ('aannemer" or 'entrepreneur'), and they document the agreement under which the contractor provides a specific service (e.g., building a construction) in exchange for the payment of a price, often a lump sum.

The proposal contains important changes to the current risk allocation between employer and contractor. We set out six significant changes below.

Six highlights of the proposed reform

1. New rules to distinguish between sales and service contracts.
   Under the new Book 7, there is a change to contract characterization rules. The distinction between a sales contract and a service contract will now be determined by two main criteria. The first is the "specificity criterion", which assesses the degree of personalization of the service provided. When the deliverable under the contract is tailored to the specific needs of the client, this is considered a service contract and not a sales contract. The second criterion considers whether the customer supplies a substantial part of the raw materials required for the project in which case the contract will be considered a service contract. The characterization of the contract is significant, as different legal rules apply to the different types of contracts. Also, it is worth noting that the characterization can occur at the level of individual clauses and does not necessarily apply uniformly to the entire contract.
2. New rules of evidence for change order requests.
   The reform will abolish certain requirements for written proof when submitting change order requests, as currently stated in art. 1793 Civil Code. This change is intended to streamline the process and reduce formalities. However, it is important to note that the general rules on evidence set out in Book 8 of the Belgian Civil Code, which largely maintain the requirement for written proof, will continue to apply.
3. More specified duties for both contractors and employers.
   Book 7 introduces more specific obligations for both contractors and employers. The employer will now have a default responsibility to coordinate the work of all the contractors who are involved in a project, or to appoint one of the contractors to perform this coordination for him (as auxiliary). At the same time, Book 7 creates specific obligations for contractors in relation to cooperation, such as the mutual information obligation. These measures are designed to improve clarity and accountability, fostering better cooperation and project outcomes.
4. Introduction of the theory of "pre-existing unforeseen circumstances".
   The new legislation provides contractors with the right to renegotiate the contract if they encounter difficulties arising from circumstances that existed prior to the conclusion of a lump sum construction contract but were unforeseen at the time of the conclusion of the contract. This new rule will mostly be relevant for unforeseen but pre-existing soil conditions that could severely affect the works in, for example, dredging contracts and foundation works.
5. Specific rules on proper performance.
   Contractors will be required to ensure that their work satisfies both the express terms of the contract and what the employer can reasonably expect (i.e., a fitness for purpose obligation). This new rule sets a specific standard for performance, emphasizing not only the technical compliance with contractual specifications but also the importance of meeting the employer's legitimate expectations regarding the finished works. How this affects a pre-agreed lump sum can be specified in the contract.
6. Uniform notification rules for both hidden and visible defects.
   The reform introduces a single notification rule for both visible and hidden defects. Any defects must now be reported within "a reasonable time frame", replacing the previous system that had separate regimes for different types of defects. This rule has been addressed in more detail in our previous client alert 3.

Timing and application

The proposed Book 7 is currently under review by the Belgian Council of State and is expected to enter into force in its current form in the course of 2026.

Once adopted, the new provisions of Book 7 will apply only to events occurring after the entry into force of the new legislation. This means that, unless the parties agree otherwise, these new Book 7 provisions will not affect contracts entered into before the entry into force of the new Book 7 provisions, including later effects of these contracts even if the effects occur after the entry into force of the new Book 7 provisions.

Conclusion

The changes introduced by Book 7 bring an important shift in the risk allocation between contractor and employer and entail substantial changes to the obligations of each party. Some of these new rules are mandatory, while others allow for deviation or further nuance in your contract. It is therefore important that you carry out a thorough review of your existing construction contracts and templates in light of the new legislation. If you would like to discuss how these reforms may impact your business or need support updating your contracts, our team is ready to assist. Contact us for tailored advice and guidance.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.