When material prices change, keep the estimate traceable.
Record where each material number came from, check it again before ordering, and carry the difference through job review so estimate accuracy and expected margin stay in view.
Quote basis → Purchase check → Job review → Closeout
At estimate time
Save what the number was based on.
For each significant material line, record the item and specification, supplier or quote reference, quote date, and validity date if one is stated. Keep the quantity, unit, unit price, waste allowance, delivery, tax treatment, exclusions, and unresolved substitutions beside it. A dated quote is a snapshot of its stated terms, not a promise that the price will remain available.
Before purchase
Confirm the price against the same scope.
Before placing an order, ask the supplier to confirm the current price and availability for the required specification, quantity, delivery location, and timing. Compare the new quote on the same basis as the estimate, including freight, taxes, minimum quantities, and substitutions. Record the confirmation date, accepted amount, and purchase-order or commitment reference. If the amount changes, update the job forecast and expected margin before treating the purchase as committed.
At job-cost review
Separate spent, committed, and still-to-buy costs.
Review each material line against the original estimate. Put received or incurred cost in actuals, open purchase orders in commitments, and needed but unordered material in remaining-to-buy. Keep those buckets separate so one order is not counted twice. Revisit them when scope, quantity, waste, delivery, or a supplier quote changes.
At closeout
Reconcile the final cost and keep the lesson.
Replace open commitments and remaining-to-buy estimates with final receipts, invoices, credits, returns, and any usable material left over. Compare the final material cost with the estimate and note the reason for each material difference, such as quantity, specification, delivery, or a changed quote. Carry that record into future estimates instead of assuming the same price or inventing a future increase.
A SIMPLE JOB-COST VIEW
Compare like with like.
The estimate is the starting allowance. Actual cost, open commitments, and the remaining cost to buy should be distinct figures. Add them for a current projected material total, then compare that total with the allowance.
| Material line | Estimated | Actual to date | Open commitments | Remaining to buy | Projected total |
|---|---|---|---|---|---|
| Materials | $2,400 | $500 | $1,200 | $800 | $2,500 |
| Variance to estimate | Projected total minus estimate | +$100 | |||
Sample figures only; replace them with the job’s own records.
- Estimated material cost
- $2,400
- Actual cost to date
- $500
- Open commitments
- $1,200
- Remaining to buy
- $800
- Projected material total
- $2,500
- Variance to estimate
- +$100
Projected total = actual to date + open commitments + remaining to buy. Do not include an amount in more than one bucket.