New Book 7 of the Belgian Civil Code: What you need to know

On 23 September 2026, the Act of 22 July 2026 inserting Book 7 “Special contracts” into the Civil Code was published in the Belgian State Gazette. This marks the next major milestone in Belgium’s ongoing overhaul of its private law and will have an impact on the real estate and construction sector.

In this first blog post, we look at the suppletive nature of the new rules, their entry into force, and the topics Book 7 covers, before paying particular attention to what matters for the real estate and construction sector in a series of upcoming blogs on the specific contracts it regulates.

A new chapter in the civil code reform

The Act of 22 July 2026 inserting Book 7 “The special contracts” (“Bijzondere contracten/Contrats spéciaux”) into the Civil Code and amending slightly Books 1, 5, 8 and 9 of the Civil Code and various other statutes was published in the Belgian State Gazette on 23 September 2026. This follows the earlier introduction of Book 8 on evidence, Book 5 on the general law of obligations, and Book 6 on non-contractual liability, continuing the step-by-step replacement of the 1804 Napoleonic Civil Code with a modernised text.

Book 7 does not create an entirely new body of law. Instead, it consolidates and updates the rules that already existed, often in fragmented or outdated form, for the contracts that businesses and individuals rely on every day.

The suppletive character of Book 7 (Article 2)

A key feature of the new Book 7 is confirmed at the very start of the text. Under Article 7.1.1 of the Civil Code, the rules of Book 7 are, in principle, suppletive law, unless it follows from the wording or the scope of a specific provision that the rule concerned is mandatory.

In practice, this means that parties generally remain free to deviate from the default rules set out in Book 7 by agreement. However, a number of individual provisions are drafted as mandatory rules, for instance to protect one of the parties (such as a tenant, in certain lease relationships) or to safeguard fundamental principles of contract law. When drafting or reviewing contracts, it will therefore remain essential to check, provision by provision, whether a given rule can be contracted out of, or whether it applies regardless of what the parties have agreed.

When will Book 7 enter into force?

Article 50 of the Act provides that it enters into force on the first day of the twelfth month following the month of its publication in the Belgian State Gazette, i.e. on 1 September 2027.

Book 7 will apply to all legal acts and legal facts that occur after its entry into force. Unless the parties agree otherwise, the previous rules will continue to apply to the future effects of legal acts and legal facts that arose before the entry into force of the Act, and, by way of exception to that principle, also to legal acts and legal facts occurring after the entry into force of the Act where they relate to an obligation arising from a legal act or legal fact that occurred before the Act’s entry into force. In other words, existing contracts and the obligations flowing from them will, as a rule, continue to be governed by the current (old) regime even after 1 September 2027, unless the parties decide otherwise.

A handful of provisions enter into force earlier. By way of derogation, Articles 6, 8, 11, 14 and 15 of the Act already entered into force on 3 October 2026. These early provisions amend existing Civil Code articles rather than Book 7 itself, and include some notable changes:

• Article 5.89 of the Civil Code is amended so that clauses exonerating a debtor from liability for fault causing harm to a person’s physical or psychical integrity are now deemed unwritten, extending the existing protection (previously limited to physical integrity) to psychological harm as well.
• Articles VI.43 and VI.44 of the Code of Economic Law, which dealt with the delivery of goods, are repealed.
• Article 5.80 of the Civil Code is also amended: while transfer of ownership in a sale continues to occur upon the exchange of consent, it no longer automatically entails transfer of risk, which will now only pass upon delivery of the item sold.

What does Book 7 cover?

Book 7 brings together the rules on a broad range of contracts that are central to both commercial and everyday legal relationships. Based on the legislative work and the structure of the new Book, it notably covers:

• Sale and exchange, including a unified conformity regime replacing the former distinction between hidden and apparent defects, new rules on transfer of ownership and risk, and new limitation periods for conformity claims;
• Lease, being the general (common law) lease regime, which does not replace the specific statutes on residential or commercial leases but introduces changes such as a codification of precarious occupancy agreements and new rules on fit-out works and termination;
• Service contracts, being a new, unified regime bringing together what used to be separate contracts for hire of work (including construction contracts), agency (mandate) and deposit, subject to common rules on matters such as cooperation duties, coordination between multiple contractors, and provisional and final acceptance;
• Loan agreements, including a revised regime for interest-bearing loans;
• Aleatory contracts, such as life annuities and other chance-based agreements; and
• Contracts relating to disputes, including settlement (transaction) agreements and escrow arrangements, as well as loan for use (commodatum).

Rather than addressing a narrow area of contract law, Book 7 revisits a significant part of the contractual framework that businesses rely on in their day-to-day operations.

What’s next?

With entry into force set for 1 September 2027, businesses have time to prepare, but given the scope of the reform, that time is best used now. Standard agreements, general terms and conditions, and precedent contracts built on the current regime may need to be revisited well before the new rules take effect.

In the coming weeks, we will publish a series of follow-up blogs taking a closer look at the specific contracts addressed in Book 7 that are relevant for the real estate and construction sector. We will highlight what these changes mean in practice for developers, contractors, architects, landlords and tenants, and other real estate and construction market participants. Stay tuned.

This blog post is for general informational purposes only and does not constitute legal advice.

Écrit par

• Lieven Peeters

  Partner