Variation Orders in Construction: How to Manage Them From Instruction to Payment

What is a variation order in construction?

A variation order (VO) is a formal change to what the contractor must build, or when, or how. It may add work, omit work, change quantities, change specifications or alter access and sequence. Depending on the contract it can be called a variation, change order, site instruction or instruction to proceed, and the terms are not always interchangeable. The glossary has a short definition of a variation order.

A VO matters because it can change both cost and time, and because work done without one is hard to get paid for.

What causes variation orders?

• Client or end-user requirements that change after award.
• Design development, clashes or errors discovered on site.
• Authority comments that require redesign.
• Unforeseen ground or existing-condition issues.
• Quantities that differ from the BOQ in a measure-and-value contract.
• Value engineering agreed by both parties.

Not every deviation is a variation. Contractor-driven changes, rework and defects are usually not compensated, so classify the cause honestly at the start.

What is the step-by-step variation order process?

1. Instruction or trigger. The consultant or client issues an instruction, or the contractor identifies a change and flags it.
2. Notice. The contractor notifies within the contract's time limit. Missing a notice period is the most common reason valid claims fail, so check the clause in your contract.
3. Quotation. The contractor prices the change using the contract's valuation rules: existing BOQ rates, adjusted rates or daywork, in the order your contract prefers.
4. Time impact. Where programme is affected, the contractor submits a time assessment. See the extension of time calculator for a quick illustration of how delay days stack up.
5. Review and negotiation. The consultant checks quantities and rates, and the client approves or rejects.
6. Approval and issue. The signed VO becomes part of the contract value.
7. Execution and recording. The change is built and recorded with inspections and photos.
8. Payment. Approved VO value is claimed in the next interim payment application.

How do you price a variation?

Pricing hierarchies differ by contract, but the usual order of preference is:

1. Use the existing BOQ rate where the work is of similar character and conditions.
2. Adjust an existing rate where the work differs in some measurable way.
3. Build up a new rate from resources (labour, materials, plant, overhead and profit) with supporting quotes.
4. Use daywork rates where work cannot be measured in advance and the contract allows it.

Always keep the supporting calculation. The variation and change order calculator helps you sketch the net effect of additions and omissions.

What is the difference between additions, omissions and adjustments?

• Addition: extra quantity or new scope.
• Omission: work removed from the contract.
• Adjustment: a change to rate or quantity of an existing item.

Net contract value is the original value plus additions and adjustments minus omissions. Omissions deserve the same discipline as additions, because clients track the net figure.

How do variations affect time and delay damages?

A variation that adds work or changes sequence can delay completion. If the contract allows an extension of time, the contractor must usually show how the change affected the critical path. Without a time extension, the original completion date still applies, which can expose the contractor to liquidated damages. Pair every cost submission with a time statement, even if the statement says "no time impact".

How do you stop variations becoming disputes?

• Never start significant changed work without written instruction.
• Keep a single register with number, date, description, status and value.
• Record verbal instructions in a same-day email or minute.
• Attach measurement, photos and inspection approvals to each VO.
• Review the register in every progress meeting.
• Separate approved, pending and rejected values in reports, so the real exposure is visible.

For the wider picture of claims prevention, read construction claims and dispute prevention.

How are variations tracked in Arkan?

Arkan is construction management software, not an ERP. In the BOQ module, variations track changes against an item's original quantity or rate, classified as Addition, Adjustment or Omission, and follow an approval workflow. The variation value is calculated from the quantity and unit rate, approved and pending values are separated, and the item shows its net revised value. Approved changes then flow into payment requests through the Finance module. See Variation Orders and BOQ, or book a demo.