The mechanism
Belgian law recognises the binding force of validly formed agreements: what the parties agreed applies to them. The cited standard therefore binds through the contract.
Applied to standards, that principle produces a direct effect. If the parties refer expressly to a standard in their agreement, they cannot later disregard it on the ground that compliance with a standard is voluntary.
The standard has not changed nature. It is the contract that gives it force, exactly as regulation referring to it would.
The three vehicles producing that effect
They share neither scope nor addressees.
| Vehicle | Who is bound | Scope |
|---|---|---|
| Regulation | all projects covered | general and impersonal |
| A permit | the permit holder | limited to the authorised project |
| A contract document | the parties to the contract | limited to the contractual relationship |
The permit deserves particular attention. A permit condition referring to a standard makes it binding for that project, independently of what the works contract provides. A contractor may therefore be bound by a standard absent from its contract, if the permit imposes it on the client.
Checking permit conditions is therefore part of reading a file, as much as the specification.
What to write
The minimum form is brief, and its brevity is misleading. Three elements suffice to make the clause operative.
It suffices to state the number of the standard and its year. That statement produces the full contractual effect, without any need to reproduce the content of the standard.
Three refinements materially improve the security of the clause. They concern the version, the scope and the proof.
State whether the reference is dated or undated. A dated reference freezes the version, an undated one follows developments. That choice is developed in the guide on measurement and specification.
State the scope of the reference. A standard often has parts, annexes and options. Referring to the whole standard and referring to one of its parts do not create the same commitment.
Provide for equivalence. In public contracts, requiring a standard is understood as a performance requirement, and an equivalent solution under another framework must be capable of being proposed.
The traps of a badly drafted citation
Four costly configurations, regularly encountered. They stem from vague or open references.
Citation without a year. In a dispute about which version applies, each party will invoke the one that suits it, and nothing will settle the matter.
Blanket citation. Referring to an entire body of standards, without stating the applicable parts, commits well beyond what the drafter had in mind.
Citation of a withdrawn standard. A reference to a document that no longer exists creates an obligation impossible to satisfy, and the clause will have to be interpreted.
Contradictory citation. Two contract documents citing incompatible standards force recourse to the hierarchy of documents, where one exists.
The effect on the burden of proof
A point explaining why this clause is so powerful despite its brevity. It transfers the standard into the contractual field.
Without citation, a standard counts as good practice: whoever departs from it must justify the equivalence of their solution technically. That is a technical discussion.
With citation, non-compliance becomes a breach of contract. The discussion ceases to be technical and becomes legal, and the argument of equivalence no longer suffices if the contract did not provide for it.
That is precisely why an equivalence clause deserves to be written rather than assumed. Its absence closes the door on alternative solutions.
What this means for a professional
Four rules.
Read the permit conditions as much as the specification, since both may impose standards.
Cite with number, year and scope, rather than by the name of the standard alone.
Check that the standards cited still exist and have not been withdrawn or superseded.
Write the equivalence clause where an alternative solution should remain open, because its absence closes the discussion.
This article reflects the position of the rules at the date of checking and serves professional orientation. It does not constitute legal advice and does not replace assessment of the individual case.