Priority of Contract Documents — Resolving Conflicts
A construction contract is not a single document. It is a collection of documents — each drafted at a different time, by a different person, with a different purpose. The conditions of contract establish the legal framework. The specification defines technical standards. The drawings show the design intent. The bills of quantities price the work. The programme establishes timing. When these documents conflict — as they routinely do — the question is: which document governs?
The Problem
Conflicts between contract documents are among the most common triggers for construction disputes, and among the most avoidable. A specification that requires one material, alongside a drawing that shows another, creates a genuine question about what the contractor is obliged to provide — and what it is entitled to be paid for. Where the answer to that question differs significantly from the contractor’s pricing assumptions, a claim arises.
Common sources of conflict include: drawings and specification updated after bills of quantities were prepared; employer’s special conditions conflicting with standard form conditions; preambles to bills of quantities that expand or restrict the scope of the works described in individual bill items; and addenda issued during the tender period that were not incorporated consistently across all documents.
The Legal Principle
The most straightforward resolution to document conflicts is an express priority clause — a clause that specifies which document prevails in the event of conflict. Standard form contracts typically include such clauses. FIDIC Red Book 1999, for example, at Clause 1.5 establishes a priority order: the Contract Agreement, the Letter of Acceptance, the Letter of Tender, the Particular Conditions, the General Conditions, the Specification, the Drawings, the Schedules, and any other documents listed in the Contract.
Where no priority clause exists, or where the conflict falls outside its scope, courts apply two presumptions: the more specific provision overrides the more general, and the later document overrides the earlier. These presumptions are rebuttable and courts will look at the commercial context.
Practical Application
Before executing the contract, review the priority clause carefully and consider whether the ordering reflects the risk allocation intended. A priority order that places the specification above the bills of quantities is commercially significant: it means the scope obligation (defined in the specification) prevails over the pricing basis (the bills). Any discrepancies between the specification and the bills that emerge before execution should be resolved expressly.
During construction, when a conflict is identified, do not simply proceed on the basis of the document you prefer — notify the engineer/contract administrator and seek a formal instruction. This ensures that the conflict is on record and that any additional cost is captured in the appropriate claims process.
Risks
The risk of an unresolved document conflict is that the contractor prices work on one basis (the bills) but is obliged to perform on another (the specification), without a clear mechanism for recovering the difference. Alternatively, the contractor performs to the lower standard (as described in the bills) and is then required to re-execute work to meet the specification standard, with uncertain recovery prospects.
Mitigation
Conduct a thorough document review before executing the contract. Identify all conflicts and resolve them by express agreement or by amendment. Maintain a conflict register during the project to track issues as they emerge and ensure that the contract administrator’s instructions on conflicts are properly documented.
Conclusion
Document conflicts are preventable with rigorous pre-contract review. Where they arise despite best efforts, the priority clause provides the resolution mechanism — but its implications must be understood before the contract is signed, not after a dispute arises.