Construction Variation Claim Assessment in Singapore.

Construction variations can affect scope, quantities, specifications, sequence and time. A sound assessment separates three questions: what changed, whether the contract treats it as a variation, and how the resulting adjustment should be valued. Mixing these questions often leads to disagreement and slow final accounts.

Start with the instruction and contract

Identify who issued the direction, when it was issued and whether that person had authority under the contract. The record may be a formal architect's or superintendent's instruction, revised drawing, site direction, request for quotation, confirmed meeting minute or other written communication recognised by the contract.

The assessment should refer to the relevant variation and valuation clauses. It should also note notice requirements, time limits and any procedure for agreeing quotations before work proceeds.

Define the changed scope

A clear comparison between the original and revised requirements is essential. Marked-up drawings, specifications, sketches and photographs can show additions, omissions and altered work. The assessment should avoid valuing the entire revised element when part of it was already included in the contract.

• Identify the original contractual scope
• Record the revised requirement and instruction date
• Measure added and omitted quantities separately
• Check whether abortive work, rework or access changes are involved
• Distinguish direct variation cost from any time-related claim

Select the valuation basis

Many contracts establish an order of valuation. Existing contract rates may apply where the varied work is of similar character and carried out under similar conditions. Adjusted or new rates may be appropriate where character, quantity, location or working conditions differ materially. Daywork should only be used where the contract permits it and contemporaneous labour, plant and material records are available.

New-rate build-ups should show quantities, material quotations, labour productivity, plant, wastage and applicable overhead and profit treatment. Unsupported lump sums are difficult to assess consistently.

Review supporting records

The quality of the records often determines how efficiently a claim can be resolved. Relevant evidence may include purchase orders, supplier and subcontractor quotations, delivery orders, timesheets, plant records, site diaries, progress photographs, correspondence and approved shop drawings.

Actual cost is not always the contractual valuation basis, but reliable records can demonstrate what resources and conditions were involved and help test the reasonableness of a proposed rate.

Avoid double counting

Check whether preliminaries, attendance, wastage, overhead, profit or design costs are already included in a rate or claimed elsewhere. Omissions should be valued consistently with additions. Credits should also reflect whether omitted work had already been procured or partly completed when the change was instructed.

Maintain a variation register

A live register gives the project team a common commercial record. It should identify the instruction reference, description, submission date, contractor's amount, assessed amount, agreed amount and current status. Pending variations should carry realistic forecasts so the cost report does not understate likely final expenditure.

• Potential change identified
• Instruction or entitlement under review
• Quotation requested or submitted
• Measurement and rate assessment completed
• Amount agreed or determined
• Included in certificate and final account

Common causes of disagreement

• No clear written instruction
• Different interpretations of the original scope
• Use of new rates where contract rates may apply
• Incomplete measurement backup
• Late notification after records are no longer available
• Combining direct work cost with disruption or prolongation without separation
• Failure to credit omitted work

What an independent quantity surveyor can provide

An independent quantity surveyor can review the measurement, test rates and quotations, identify missing records, prepare a reasoned assessment and maintain the commercial reconciliation. The result should show both agreed and disputed components, enabling the parties to focus on the matters that genuinely remain unresolved.