How to Prepare a Construction Variation
Quick answer
A defensible variation has four parts: the instruction (who directed the change and when), the scope (exactly what's extra or different), the cost build-up (labour, plant, materials, subcontractors and other, each with markup), and the approval trail. Price it and submit it before the work disappears into the job.
1. Anchor it to an instruction
Every variation starts with why. Record the source — engineer's instruction, client email, site meeting minute, latent condition — with a reference and date. 'The client told us on site' is worth very little six months later; an EI number or email is worth everything. If the contract requires notice within a set time, that clock is already running.
2. Describe the change, not the argument
Write the scope factually: what was in the contract, what changed, and what the extra or different work is. Keep it to what a reviewer can verify — 'additional 24 m of 300 mm SW line including excavation in rock and reinstatement' beats a paragraph of justification. Attach the marked-up drawing or photos.
3. Build the cost by category
Formulas
Direct cost = labour + plant + materials + subcontractors + other
Markup applied per category (own work vs subcontract often differ)
Variation value = direct cost + markup (+ GST where applicable)
Worked example
Labour: 2 crew × 2 days = $2,720 @ 15 % = $3,128
Plant: digger + truck 2 days = $3,400 @ 15 % = $3,910
Materials: pipe & bedding = $1,850 @ 15 % = $2,127.50
Subcontract: reinstatement = $1,200 @ 10 % = $1,320
Variation total (excl. GST) = $10,485.50
4. Track it to approval
A priced variation that never gets approved is a donation. Track each one through pending → submitted → approved, and don't let approved variations get missed off the next progress claim — they're part of the revised contract value.
Check your contract's variation and notice clauses; some contracts price directed variations from schedule rates and others from actual cost, and the difference matters when you build the claim.
- —Number variations sequentially (VO-001, VO-002…) and reference them in claims
- —Keep daily records for time-and-materials variations — dockets win arguments
- —Update the revised contract value as approvals land
Fieldlink captures variations from site, prices them from your rates and tracks approval against the job — no lost paperwork.
See Fieldlink Variations