Flemish Duty of Care & Chain Liability in Construction: What Clients, Contractors and Subcontractors Must Change in 2026

From 1 January 2026 the Flemish duty of care construction 2026 Belgium framework imposes a new zorgvuldigheidsplicht (duty of care) and strengthened chain-liability regime on every party in a construction subcontracting chain operating in Flanders. The measures, introduced by Flemish decree and accompanied by a six-month tolerance period for enforcement, require clients, main contractors and subcontractors to overhaul procurement documents, standard contracts and site-level compliance files before awarding or accepting new work. Separately, Belgium’s extension of the VAT revision period to 15 years for durable renovations adds a further cost-allocation dimension that construction contracts must now address.

This guide delivers the practical contract clauses, compliance checklists and party-by-party action plans that project teams need to implement the 2026 changes without delay.

Executive Summary, What Changed and What You Must Do Now

The Flemish Government’s decree on chain liability (ketenaansprakelijkheid) and the accompanying implementing decision on the duty of care (zorgvuldigheidsplicht) took effect on 1 January 2026. The decree targets illegal employment in subcontracting chains and makes every link in the chain, from the project owner down to the lowest-tier subcontractor, potentially liable unless that party can demonstrate it discharged its duty of care. Social inspection services have confirmed a six-month tolerance window, meaning enforcement will focus on guidance and education until 1 July 2026, after which full sanctions apply.

The rules cover all construction-sector activities carried out in the Flemish Region, including civil engineering, building, finishing trades, installation and demolition. Both Belgian and foreign entities performing or commissioning works in Flanders fall within scope. Temporary agency work is addressed through a parallel code of conduct for staffing agencies.

The six immediate actions every construction-sector participant should take are: (1) audit all current subcontract templates against the new documentation requirements; (2) insert duty-of-care representations and audit-right clauses into main contracts and subcontracts; (3) build an onboarding checklist for new subcontractors that captures every required document; (4) update procurement and tender documents with pre-qualification language; (5) review insurance cover for chain-liability exposure; and (6) for renovation projects, model the impact of the 15-year VAT revision on contract pricing. For a comprehensive set of ready-to-adopt template clauses, refer to the clause bank section below.

Legal Framework, Duty of Care & Chain Liability Explained (Flanders)

What Exactly Is the Zorgvuldigheidsplicht?

The duty of care obligation in construction, formally the zorgvuldigheidsplicht, requires each party that engages a contractor or subcontractor in Flanders to take reasonable steps to verify that its direct contractual partner is lawfully employing workers. It is not a strict-liability standard: a party that can demonstrate it performed the prescribed checks and maintained a compliant care-file may rebut the presumption of chain liability. The Flemish Government’s official guidance sets out the specific documents and verifications that discharge this duty.

The duty of care obligation in construction represents a shift from reactive enforcement to proactive compliance. Historically, Belgian social-inspection law already provided for joint and several liability (hoofdelijke aansprakelijkheid) for unpaid wages when illegal employment was detected. The Flemish decree extends and systematises this principle, requiring that every contracting party in the chain, not merely the direct employer, demonstrate affirmative due diligence. A party that fails to collect or retain the required evidence loses the ability to invoke the statutory defence and faces the full force of chain liability.

Who Is Within Scope, Subcontracting Chain Rules Flanders 2026

The decree applies to three categories of entity operating within the Flemish Region:

• Clients and project owners. Any natural or legal person commissioning construction works, including private developers, public authorities (to the extent not covered by separate public-procurement rules) and property owners procuring renovation services.
• Main contractors. Enterprises awarded the principal construction contract, whether Belgian-registered or foreign, that subsequently subcontract part or all of the works.
• Intermediary contractors and subcontractors. Every tier of the subcontracting chain, second-tier, third-tier and beyond, is captured. A subcontractor that itself engages labour or further subcontracts must also discharge the duty of care towards its own chain.

Certain high-risk sectors (risicosectoren) receive heightened attention from social inspectors, including demolition, scaffolding, earthworks and finishing trades with a high concentration of posted or third-country national workers. While the documentary requirements are the same across sectors, inspection frequency and scrutiny are expected to be significantly greater in these categories. For essential construction law terminology, consult the accompanying glossary.

Timeline & Enforcement, Key Dates, Grace Period and Inspection Approach

Understanding the enforcement timeline is critical for compliance planning. The chain liability construction Belgium framework follows a phased implementation, giving market participants a defined window to adapt before full sanctions commence.

The grace period is not a delay in the law’s application, obligations are legally binding from 1 January 2026. Industry observers expect social inspectors to treat the tolerance window as a final opportunity for parties to demonstrate good-faith compliance efforts. Entities that have not begun implementing changes by 1 July 2026 will face sanctions without the benefit of further leniency.

Who Must Do What, Obligations by Party

The practical effect of the Flemish duty of care construction 2026 Belgium rules differs significantly depending on where a party sits in the subcontracting chain. The comparison table below summarises the core obligations and the contract changes required for each entity type.

Client Actions

Clients bear the first-line responsibility to select compliant main contractors. Before signing a construction contract, the client should verify the contractor’s registration in the Crossroads Bank for Enterprises (Kruispuntbank van Ondernemingen), confirm active social security standing and request evidence of employers’ liability insurance. Where the project involves posted workers, clients should confirm that Limosa declarations have been filed.

Main Contractor Actions

Main contractors occupy the most operationally intensive position in the chain. They must establish a documented pre-qualification procedure for every subcontractor, maintain an up-to-date compliance dossier per project, and ensure that each subcontract contains a binding obligation on the subcontractor to provide evidence of legal employment for every worker deployed on site. For guidance on managing delays that may result from enhanced pre-qualification, see claiming compensation for developer delays.

Subcontractor Actions

Subcontractors, including those at the second and third tier, should prepare a standardised compliance pack that can be delivered promptly to any main contractor or intermediary contractor. The pack should contain copies of company registration, social security certificates, proof of insurance and, where applicable, individual work permits or Limosa declarations for posted workers. Subcontractor liability in Flanders now extends to a duty to cooperate with on-site audits and to flow down identical obligations to any further sub-subcontractors.

How to Update Construction Contracts, Clause Bank & Drafting Notes

Revising construction contracts Belgium 2026 is arguably the most urgent practical step. Below are six template clauses designed to bring main contracts and subcontracts into line with the new requirements. Each clause should be adapted to the specific project and reviewed by qualified Belgian construction counsel before use.

Clause 1, Duty-of-Care Representation & Covenant

“The Contractor represents and warrants that it complies, and shall continue to comply throughout the Term, with all applicable Flemish legislation concerning chain liability and the duty of care (zorgvuldigheidsplicht), including by maintaining a compliant care-file containing the documents specified in [Schedule X]. The Contractor shall promptly notify the Client of any change in its compliance status.”

Clause 2, Subcontractor Pre-Qualification & Documentation

“Prior to engaging any Subcontractor, the Contractor shall (a) verify the Subcontractor’s registration with the Crossroads Bank for Enterprises, (b) confirm active social security standing, (c) collect copies of valid work permits for all non-EEA workers to be deployed on the Works, and (d) obtain evidence of employers’ liability insurance. The Contractor shall retain these documents in its care-file and make them available to the Client upon request.”

Clause 3, Flow-Down Obligation

“The Contractor shall include in every subcontract a provision requiring the Subcontractor to (i) comply with all Flemish chain-liability and duty-of-care requirements, (ii) impose equivalent obligations on any further sub-subcontractor, and (iii) provide the Contractor with all documentation necessary to discharge the Contractor’s own duty of care.”

Clause 4, Audit & Access Right

“The Client (or its authorised representative) shall have the right, upon reasonable notice, to audit the Contractor’s and any Subcontractor’s care-file, site records and payroll documentation to verify compliance with the duty of care. The Contractor shall ensure that equivalent audit rights are included in all subcontracts.”

Clause 5, Chain-Liability Indemnity

“The Contractor shall indemnify and hold harmless the Client against all losses, fines, penalties and costs arising from a breach of chain-liability obligations by the Contractor or any member of its subcontracting chain, except to the extent that such breach results directly from an act or omission of the Client.”

Clause 6, Insurance Obligation

“Each party in the subcontracting chain shall maintain, at its own cost, (a) employers’ liability insurance, (b) professional indemnity insurance and (c) general third-party liability insurance, each in amounts not less than [€ amount] per occurrence. Evidence of cover shall be provided to the immediate upstream party before the commencement of any Works.”

Procurement Tender Language

Tender documents should include a mandatory pre-qualification questionnaire requiring bidders to confirm compliance with the Flemish duty-of-care requirements. The questionnaire should request documentary evidence as a condition of tender evaluation, making non-compliant bids ineligible. This shifts the compliance burden to the earliest stage of the procurement cycle and reduces the risk of appointing a non-compliant contractor.

Sample Subcontractor Questionnaire Items

• Company registration number and date of registration in the Crossroads Bank for Enterprises.
• Social security certificate confirming no outstanding contributions.
• Work-permit schedule listing all non-EEA workers to be deployed, with permit numbers and expiry dates.
• Insurance certificates for employers’ liability, professional indemnity and general third-party liability.
• Confirmation of subcontracting intent, will the bidder sub-subcontract any portion of the works? If so, provide the compliance checklist for that tier.
• Signed declaration that the bidder has read and will comply with the Flemish chain-liability and duty-of-care decree.

Documentation & Operational Controls, Compliance Checklist Construction Belgium

Maintaining a robust care-file (zorgvuldigheidsdossier) is the single most important operational safeguard. Without it, a party cannot invoke the statutory defence against chain liability. The table below sets out the documents to collect, when to collect them and how long to retain them.

Operational Controls

• Digital care-file. Maintain both a physical site file and a centralised digital repository (cloud-based, with access logging) so that documents can be produced immediately during a social inspection.
• Quarterly refresh cycle. Social security certificates and insurance certificates should be refreshed at least quarterly. Build automated reminders into project-management software.
• Site access control. Link site-access badges to compliance verification. No worker should access the site without a confirmed match to a valid work permit and Limosa declaration (where applicable).
• Escalation protocol. Define a clear escalation path, from site supervisor to project manager to legal counsel, for any documentation gap or suspected non-compliance discovered during works execution.
• Inspection readiness drill. Conduct at least one mock social-inspection exercise per project during the tolerance period (before 1 July 2026) to test the completeness and accessibility of the care-file.

Tax & VAT Implications, 15-Year Revision and Contract Consequences

Running parallel to the Flemish duty-of-care changes, Belgium has extended the VAT revision period (herzieningstermijn) to 15 years for durable renovations of immovable property. Previously, the standard revision period was five years (or in some cases ten years). The 15-year VAT revision Belgium rule means that if a renovated building’s use changes within that extended window, for example, from taxable to exempt, the initially deducted input VAT must be partially repaid to the treasury.

For developers and main contractors, the likely practical effect will be threefold:

• Contract price allocation. Contracts should clearly separate the supply of goods from the supply of services, and separately identify durable renovation works, to enable precise VAT treatment and future revision calculations.
• Risk-sharing provisions. Include a VAT-adjustment clause that allocates the financial risk of a future revision event between the parties. For example, if the client changes the use of the building within 15 years, the developer should not bear the resulting VAT clawback without a corresponding adjustment mechanism.
• Invoice granularity. Subcontractor invoices should itemise works with sufficient detail to allow upstream parties to distinguish between durable renovation elements (subject to the 15-year period) and other works (subject to shorter periods). Industry observers expect the Belgian tax authorities to scrutinise invoice descriptions more closely in the years ahead.

The VAT 15-year renovation Belgium change applies to renovation works completed from the date of the amendment’s entry into force. For projects already in progress, transitional rules may apply depending on the date of the relevant invoicing events. Consult specialised VAT counsel to model the impact on projects where the building’s future use is uncertain or where mixed-use is planned.

Risk Allocation & Insurance Considerations

The chain-liability framework fundamentally alters the risk landscape. Every party in the subcontracting chain should review its insurance programme against the following benchmarks:

• Employers’ liability insurance must be in place for every entity employing workers on site. Under the chain-liability regime, a client or main contractor may face claims for unpaid wages even if it is not the direct employer, ensure that the policy covers such contingent liabilities or that the indemnity structure addresses the gap.
• Professional indemnity insurance should cover the cost of defending against and settling chain-liability claims, including administrative fines where insurable under Belgian law.
• Conditional indemnities vs. insurability. Blanket indemnity clauses that purport to transfer all chain-liability risk to the subcontractor may be unenforceable if the subcontractor lacks the financial capacity or insurance to honour them. Draft indemnities that are proportionate, insurable and backed by evidence of cover.
• Subcontractor insurance verification. Use the pre-qualification checklist (Clause 2 above) to verify subcontractor insurance before contract signature and require annual renewal evidence.

Enforcement Scenarios & Dispute Examples

The following three hypothetical scenarios illustrate how the Flemish duty of care construction 2026 Belgium rules may play out in practice. While these are not decided cases, they reflect the risk patterns that industry observers expect to emerge once full enforcement begins.

• Scenario 1, Client exposed through chain liability. A private developer commissions a main contractor, who engages a second-tier subcontractor employing third-country nationals without valid work permits. Social inspectors discover the infringement. Because the developer failed to collect social security certificates from the main contractor and never requested evidence of subcontractor compliance, it cannot invoke the duty-of-care defence. The developer faces joint and several liability for unpaid wages and a potential administrative fine. Recommended response: insert pre-qualification and audit-right clauses (Clauses 2 and 4) and verify documentation before project commencement.
• Scenario 2, Main contractor audited and fined. A main contractor maintains a care-file but has not refreshed social security certificates since the start of the project (nine months earlier). During a social inspection, the certificates are found to be expired. The inspector treats the file as incomplete, and the contractor loses the benefit of the defence for the period of non-compliance. Recommended response: automate quarterly refresh reminders and include a contractual obligation on subcontractors to deliver updated certificates proactively.
• Scenario 3, VAT reclassification risk after major renovation. A developer renovates a commercial building under a contract that does not separately identify durable renovation works. Five years later, the building is converted to exempt residential use. The Belgian tax authority applies the 15-year revision and reclaims a substantial portion of input VAT, but the developer cannot accurately calculate the portion attributable to durable works because the invoices were not sufficiently itemised. Recommended response: require granular invoicing (see Tax & VAT section above) and include a VAT-adjustment mechanism in the contract. For related guidance on delays in construction projects and their legal remedies, see the linked resource.

Practical Next Steps & 90-Day Action Plan

Compliance with the Flemish duty of care construction 2026 Belgium requirements is not optional, and the six-month tolerance period is narrowing. The prioritised action plan below provides a roadmap for the next 90 days.

Entities that complete these steps before 1 July 2026 will be well-positioned to demonstrate good-faith compliance when full enforcement commences. For a directory of Belgian construction law specialists, visit the Global Law Experts lawyer directory.

Appendices & Resources

• Vlaanderen, Chain liability and illegal employment guidance: Official scope, documentary requirements and inspection procedures.
• Vlaanderen, Flemish Government decision on ketenaansprakelijkheid: Legislative decision record and decree references.
• Vlaanderen, Wijzigingsbesluit on zorgvuldigheidsplicht: Enforcement start date and six-month tolerance details.
• BDO Belgium, 15-year VAT revision for durable renovations: Practical tax analysis for developers and contractors.
• Partena Professional, Duty of diligence and chain liability alert: HR and compliance perspective.
• LegalDirect, Advisory on zorgvuldigheidsplicht and ketenaansprakelijkheid: Enforcement and grace-period commentary.
• Clause bank download (PDF): A downloadable document containing all six template clauses and the subcontractor pre-qualification questionnaire is forthcoming, check back for the link.

Sources

1. Vlaanderen, Ketenaansprakelijkheid bij illegale tewerkstelling
2. Vlaanderen, Beslissingen Vlaamse Regering: Ketenaansprakelijkheid
3. Vlaanderen, Wijzigingsbesluit Zorgvuldigheidsplicht & Ketenaansprakelijkheid
4. BDO Belgium, BTW-herzieningstermijn voor duurzame verbouwingen uitgebreid tot 15 jaar
5. Partena Professional, Flanders Introduces Duty of Diligence for Contractors 2026
6. LegalDirect, Zorgvuldigheidsplicht en Ketenaansprakelijkheid
7. Vialto Partners, Belgium: Flemish Chain Liability Postponed to 1 January 2026
8. VAT-Consult, BTW-herzieningstermijn