Book 7 and Commercial Leases in Belgium (2026): Responsibility for Building Works, Repairs and Defects

Belgium’s reformed Civil Code now includes Book 7 on special contracts, and it fundamentally reshapes how responsibility for building works, repairs and construction defects is allocated between landlords, tenants and contractors. For anyone involved in a commercial lease in Belgium, understanding book 7 construction leases Belgium rules is no longer optional; it is an immediate compliance priority. This guide explains the new default obligations, maps out who can sue whom when defects appear in leased premises, provides sample lease clauses ready for adaptation, and sets out a practical insurance and risk-management checklist designed for both sides of a commercial tenancy.

Key takeaways at a glance:

• Landlord default obligation confirmed. Book 7 preserves and clarifies the landlord’s duty to carry out major structural repairs, but the parties may now contractually reallocate this, provided the clause is unambiguous.
• Conformity regime for construction works. Construction agreements are treated as a subcategory of service agreements under Book 7, introducing codified conformity standards and remedies that ripple directly into lease relationships.
• Claim paths are more complex. Whether a tenant sues the landlord, the contractor or a subcontractor depends on who contracted the works, what the lease says, and whether flow-down or assignment clauses exist.
• Lease clauses need updating now. Ingoing/outgoing condition reports, defect notice protocols, insurance requirements (including decennial coverage) and contractor flow-down clauses all require revision to align with Book 7.

What is Book 7? Quick legal background on Book 7 and the Belgian Civil Code

Book 7 is the newest addition to Belgium’s modernised Civil Code, replacing the scattered provisions on “special contracts” that previously sat in the old Code civil / Burgerlijk Wetboek. It consolidates and updates the rules governing sales, leases, service agreements (including construction agreements), mandates and several other named contract types into a single, coherent framework. The reform reflects a broader legislative project, initiated over a decade ago, to bring Belgium’s civil law in line with contemporary commercial practice and European contract-law principles.

Key legislative dates and scope

The legislative proposal for Book 7 was submitted to the Belgian Parliament and subsequently enacted, with publication in the Moniteur belge (Belgian Official Journal). Book 7 entered into force in 2026, applying to contracts concluded after its effective date. For construction agreements, Book 7 introduces a distinct subcategory of the service agreement (contrat d’entreprise / aannemingsovereenkomst), complete with codified rules on conformity of works, acceptance, and post-delivery liability. In lease contexts, the updated provisions on the landlord’s obligation to deliver and maintain the premises, and the tenant’s corresponding duties, now interact directly with these construction-agreement rules whenever building works or renovations are carried out on leased property.

Practical implications:

• Book 7 applies to new contracts concluded after the entry-into-force date; pre-existing contracts remain governed by the old rules unless the parties opt in.
• Construction agreements are now expressly classified as service agreements, bringing them under a unified conformity regime.
• Lease-specific provisions update the landlord’s repair duties and the tenant’s maintenance obligations, creating new drafting requirements for commercial lease construction Belgium scenarios.

How Book 7 changes landlord and tenant obligations for works, repairs and defects

Under the old Civil Code, the division of repair obligations between landlord and tenant relied on broadly worded provisions that left significant room for contractual override and judicial interpretation. Book 7 retains the principle that the landlord bears responsibility for major repairs and structural works, while the tenant handles day-to-day maintenance and minor repairs. However, it codifies several important shifts in how conformity, defects and remedies are handled, changes that every commercial lease must now reflect.

Landlord repair obligations under Book 7

The landlord’s duty to deliver premises in good condition and to carry out major repairs during the lease term is preserved under Book 7, consistent with the analysis provided by leading Belgian commentators. This includes structural repairs, works to the roof, load-bearing walls, and essential building systems. The landlord also remains liable for latent defects, those that existed at the time of delivery but were not apparent to the tenant, unless the lease contains a valid exclusion clause (subject to strict limits, discussed below).

What changes:

• The conformity standard is now codified: the premises must conform to what was agreed and to what the tenant could reasonably expect based on the nature of the property.
• Remedies for non-conformity are systematised, the tenant may demand repair, price reduction, or in serious cases termination of the lease.
• Landlord repair obligations must be explicitly addressed in the lease; silence defaults to the statutory regime, which favours the tenant.

Tenant obligations and fit-out liability

The tenant remains responsible for routine maintenance and for repairs necessitated by the tenant’s own use or negligence. Under Book 7, tenant fit-out liability is given sharper definition: where a tenant carries out fit-out works (with or without landlord consent), the tenant bears responsibility for defects in those works unless the lease allocates it differently. Critically, if the tenant engages its own contractor, the tenant, not the landlord, is the contracting party and bears the risk of contractor non-performance or defective workmanship.

Practical implications for tenants:

• Obtain written landlord approval before commencing any fit-out, specifying standards, materials and scope.
• Ensure the fit-out contractor carries adequate insurance (professional indemnity and, where structural works are involved, decennial coverage).
• Include clear handback provisions addressing the fate of fit-out works at lease end, removal, make-good, or landlord acquisition.

Comparison table: landlord vs tenant obligations under Book 7

Who can sue whom, practical claim paths for construction defects in leased premises

One of the most common questions arising under Book 7 is: when a defect appears in leased premises, who does the injured party sue? The answer depends on the contractual chain, who commissioned the works, what the lease provides, and whether assignment or flow-down clauses are in place. Book 7’s codification of the construction-agreement conformity regime makes it essential to map these claim paths in advance.

Direct contractor claims and privity issues

Under Belgian law, the principle of privity of contract (relativité des conventions) means a party can generally only sue the other party to its own contract. In a commercial lease construction Belgium context, this creates distinct scenarios:

• Tenant sues landlord: The tenant’s primary claim is under the lease, for breach of the delivery obligation, breach of the repair duty, or the latent-defect warranty. Book 7 strengthens the remedies available (repair, price reduction, termination).
• Landlord sues contractor: If the landlord commissioned the building works, the landlord has a direct contractual claim against the contractor under the construction agreement. Book 7’s conformity rules apply, the contractor is liable for defects that existed “in germ” at the time of acceptance.
• Tenant sues contractor directly: The tenant has no direct contractual claim against the landlord’s contractor, unless the lease includes an express assignment of the landlord’s construction-agreement claims, or a flow-down clause granting the tenant step-in rights.

Subcontractor and third-party routes

Where a contractor has engaged subcontractors, additional complexity arises. Contractor liability Belgium rules under Book 7 permit the contracting party (landlord or tenant, depending on who contracted the works) to claim against the main contractor, who then has recourse against the subcontractor. In some circumstances, a direct action against the subcontractor may be available on the basis of quasi-delictual liability, but this is narrower and more difficult to establish. Lease drafting Belgium best practice is to address this proactively through flow-down and assignment clauses, discussed in the drafting section below.

Practical implications:

• Always identify in the lease who commissioned each category of works (landlord or tenant).
• Include an assignment-of-claims clause so the tenant can pursue the contractor directly if the landlord is unwilling or unable to do so.
• Consider joint appointment of the contractor (landlord and tenant as co-principals) for major works affecting leased premises.

Insurance and decennial/contractor liability in Book 7 construction leases Belgium scenarios

Book 7 does not replace Belgium’s existing insurance obligations for construction works, including the mandatory decennial liability insurance for structural defects affecting stability. However, it changes the contractual landscape within which those insurance products operate. For commercial leases, the interaction between the lease, the construction agreement, and the applicable insurance policies must be coordinated carefully to avoid coverage gaps.

Which insurances to require in a commercial lease

Industry observers expect the following insurance requirements to become standard in Belgian commercial leases post-Book 7:

• Decennial liability insurance (assurance responsabilité décennale): Mandatory for works affecting structural stability. The landlord should require the contractor to provide evidence of this coverage before works commence, and the lease should oblige the landlord to pass through the benefit of this insurance to the tenant via assignment or flow-down.
• Professional indemnity insurance: Required of architects and engineering consultants involved in design. The lease should specify minimum coverage amounts and require certificates to be lodged with both landlord and tenant.
• Building/property insurance (assurance incendie / brand- en gebouwenverzekering): Typically maintained by the landlord. The lease should include a waiver-of-subrogation clause preventing the insurer from recovering against the tenant for insured events, except in cases of gross negligence or wilful misconduct.
• Tenant’s all-risk / fit-out insurance: Required where the tenant carries out fit-out works, covering damage to the fit-out and third-party liability during construction.

Sample insurance clause

The following clause is provided for guidance and should be adapted to the specific transaction with the advice of a Belgian construction and insurance lawyer:

“Insurance obligations, construction works on leased premises The Landlord warrants that, prior to commencement of any building works affecting the Premises, the appointed Contractor shall maintain: (a) decennial liability insurance covering structural defects for a period of ten years from acceptance; (b) professional indemnity insurance with a minimum coverage of [€ amount]; and (c) contractor’s all-risk insurance for the duration of the works. The Landlord shall provide the Tenant with copies of all insurance certificates upon request. The Landlord hereby assigns to the Tenant, to the extent permitted by law, the benefit of all construction-agreement warranties and insurance claims relating to defects in the Premises.

The Landlord’s property insurance policy shall include a waiver of subrogation in favour of the Tenant, except in cases of gross negligence or intentional fault.

Status: Recommended mandatory, both parties benefit from insurance transparency.

Drafting checklist and sample lease clauses for Book 7 construction leases Belgium

The practical effect of Book 7 is that standard-form commercial leases in Belgium need updating. The following checklist and sample clauses address the most critical areas. Each clause is marked as either “recommended mandatory” (both parties should insist on inclusion) or “for negotiation” (allocation depends on bargaining position).

Ingoing/outgoing condition report clause

“Condition reports
The parties shall jointly commission an independent building surveyor to prepare a detailed ingoing condition report (état des lieux d’entrée / plaatsbeschrijving bij intrede) within [14] days of the Commencement Date. An equivalent outgoing condition report shall be prepared within [14] days before or after the Termination Date. The reports shall document the structural condition, fit-out state, and any visible defects. Any defect not recorded in the ingoing report shall be presumed to have arisen during the Lease Term unless the Tenant proves otherwise.”

Status: Recommended mandatory.

Contractor flow-down and waiver of recourse

“Assignment of construction-agreement claims
The Landlord hereby assigns to the Tenant all claims, warranties and rights of action against the Contractor and any subcontractors in respect of defects in the Premises, to the extent such defects affect the Tenant’s use and enjoyment. The Tenant may pursue such claims in its own name. The Landlord shall cooperate in the prosecution of any such claims, including by providing access to construction documentation. This assignment is irrevocable for the duration of the Lease Term and any renewal.”

Status: For negotiation, landlords may prefer to retain control of claims and cooperate on a case-by-case basis.

Insurance and indemnity clauses

“Tenant fit-out insurance and indemnity
The Tenant shall, at its own cost, maintain all-risk insurance covering tenant fit-out works for the duration of such works and for [12] months after completion. The Tenant indemnifies the Landlord against all claims, losses and liabilities arising from defects in the Tenant’s fit-out works, except to the extent such claims arise from the Landlord’s breach of its structural repair obligations.”

Status: Recommended mandatory.

“Defect notice protocol
The discovering party shall notify the other party in writing within [30] days of becoming aware of any defect affecting the structural integrity or habitability of the Premises. The notified party shall respond within [14] days, proposing a remedial programme or appointing a joint expert. Failure to notify within the prescribed period does not extinguish the claim but may affect the allocation of consequential losses.”

Status: Recommended mandatory.

“Dispute resolution, construction defects
Any dispute arising from construction defects in the Premises shall first be referred to a jointly appointed independent expert for a non-binding technical assessment. If the dispute is not resolved within [60] days of the expert’s report, either party may refer the matter to the competent courts of [Brussels / Antwerp / as agreed], or to arbitration under [applicable rules] if so elected by both parties.”

Status: For negotiation, arbitration vs court litigation depends on the parties’ preferences.

Drafting checklist summary:

• Ingoing and outgoing condition report, commissioned jointly, binding on both parties.
• Defect disclosure obligation, landlord to disclose all known defects before lease signature.
• Tenant fit-out approval and handback protocol, scope, standards, removal or retention at lease end.
• Insurance requirements, decennial, professional indemnity, building, tenant all-risk, waiver of subrogation.
• Contractor flow-down / assignment of claims, irrevocable or case-by-case, covering warranties and rights of action.
• Indemnities, cross-indemnities for respective obligations, carved out for the other party’s breach.
• Defect notice timing and response protocol, 30-day notice, 14-day response.
• Dispute resolution, expert determination first, then court or arbitration.

Practical risk management, inspections, warranties, notices and dispute resolution

Beyond the lease clauses themselves, effective risk management under Book 7 requires both landlords and tenants to follow structured processes for inspections, notice and dispute handling. The timeline below sets out the critical windows that practitioners should build into their operational workflows.

Timeline for defect notice and limitation periods

When to appoint an expert

An independent expert should be appointed immediately when: (a) there is disagreement between landlord and tenant on whether a defect is structural; (b) insurance claims may be triggered; (c) the defect may worsen if not documented promptly; or (d) the identity of the responsible party is unclear. Early expert reports are critical, courts and insurers rely heavily on contemporaneous technical evidence when adjudicating construction defects in leased premises. The likely practical effect of Book 7 will be to increase the frequency of expert appointments, as the codified conformity regime creates clearer benchmarks against which expert opinions can be measured.

Case studies, hypothetical examples under Book 7

Scenario 1: Tenant discovers hidden structural defect after completing fit-out

A commercial tenant completes a significant interior fit-out of warehouse premises. Three months later, cracking appears in a load-bearing wall, a latent defect that existed before the lease commenced but was concealed by the previous finish. Under Book 7, the tenant notifies the landlord within 30 days. The landlord is liable under the lease warranty for latent defects at delivery. The landlord, in turn, has a claim against the original building contractor under the construction agreement’s conformity regime, provided the defect existed “in germ” at acceptance. Because the lease contains a contractor flow-down clause, the tenant can also pursue the contractor directly, accelerating the resolution.

Without that clause, the tenant would be entirely dependent on the landlord to prosecute the claim.

Scenario 2: Landlord completes renovation works; defect appears within two years

A landlord renovates the facade and roof of a leased office building. Eighteen months after completion, water infiltration damages the tenant’s interior. The lease includes a defect notice protocol and an assignment-of-claims clause. The tenant notifies the landlord and the contractor simultaneously. The contractor’s decennial insurance covers the structural element of the claim. The landlord’s building insurance covers the tenant’s consequential interior damage, and the waiver-of-subrogation clause prevents the building insurer from seeking recovery against the tenant. The dispute is referred to a joint expert, whose report confirms a construction defect, enabling both insurance claims to proceed without litigation.

Conclusion, recommended next steps for Book 7 construction leases Belgium

Book 7 does not overturn the fundamentals of Belgian lease law, but it sharpens the rules, codifies conformity standards, and demands more precise drafting from both landlords and tenants. Failing to update commercial leases risks unintended liability exposure, insurance gaps, and protracted disputes over who bears responsibility for construction defects in leased premises.

For landlords:

• Audit all standard-form commercial leases against the Book 7 checklist above, prioritise insurance, condition report and flow-down clauses.
• Require contractors to provide evidence of decennial and professional indemnity insurance before any works commence on leased premises.
• Implement a structured defect notice and response protocol as a lease schedule.

For tenants:

• Insist on an assignment-of-claims clause covering the landlord’s construction-agreement warranties and insurance rights.
• Commission a thorough ingoing condition report and retain it for the full lease term, it is the single most important piece of evidence in any end-of-lease dispute.
• Maintain fit-out all-risk insurance and ensure it covers the full period of works plus at least 12 months post-completion.

Sources

1. Loyens & Loeff, Book 7 on special contracts submitted to Parliament
2. Crowell & Moring, The future of special contracts in Belgium: a new Book 7 for the Belgian Civil Code
3. Deloitte Legal, Insertion of Book 7 special contracts into the new Civil Code
4. Lexology, Book 7 construction agreements
5. PwC Legal Belgium, Real estate in the draft Book 7 of the Civil Code
6. Mondaq, Book 7: key takeaways for lease agreements
7. Mondaq, Book 7: construction agreements
8. Belgian Official Journal / e-Justice (Moniteur belge)
9. Eubelius, New rules on special contracts: legislative proposal for Book 7
10. SimontBraun, The Belgian reform of the Civil Code: a new law for specific contracts