What to check before sending a takeoff for supplier quotes

A takeoff is only as useful as the quote requests it produces. Suppliers price what you send them — if the quantities are loose, the units are ambiguous, or the assumptions are invisible, the numbers that come back are guesses, and the differences between quotes tell you nothing. This checklist is the ten minutes of review that makes supplier quotes comparable.

Check the drawing set

Confirm the drawing revision, page number, trade scope, and whether any details or schedules override the general plans before trusting a single measurement.

• Revision: quantities taken off Rev B are worthless if the job is building Rev D. Check the title block on every sheet you measured, not just the first one.
• Details override plans: a 1:20 detail with a thickened slab edge beats the 1:100 general arrangement it contradicts. Scan the detail sheets for anything that changes what you measured.
• Schedules: door, window, and fixture schedules regularly disagree with what is drawn. If you counted symbols on the plan, reconcile the count against the schedule and note which one you trusted.

Check the measurement basis

Every measured item should have a clear unit, scale, count method, and a note explaining what is included or excluded.

• Scale: verify calibration against a written dimension, not the scale bar alone — printed and re-exported PDFs drift. A slab measured at the wrong scale is wrong by the square of the error: 5% off on length is 10% off on area. Re-check any sheet where the calibration was set from a single short dimension.
• Units: m² or m³? Lineal metres or item counts? A "40" with no unit forces the supplier to guess, and they won't guess in your favour.
• Waste: state whether quantities are net or include an allowance. "4.2 m³ net, add your own waste" and "4.4 m³ including 5%" are both fine — silence about which one you sent is not.

Check supplier assumptions

Suppliers need more than a number. Include delivery location, preferred date, access constraints, product specification, and whether unloading or pumping is required.

A worked example — a 40 m² garage slab at 100 mm gives 4.0 m³ net, call it 4.2 m³ with 5% waste. The quantity is the easy half. The concrete supplier still needs: strength grade (say N25), slump, mesh or fibre spec, whether the truck can reach the pour or a pump is needed, and the suburb — because cartage and pump hire can move the quote more than the concrete itself. Two suppliers quoting "4.2 m³" against different assumptions aren't quoting the same job. Put the assumptions in the request so the quotes come back comparable. (For quick slab arithmetic before the formal takeoff, the concrete calculator does the volume-and-bags conversion.)

Check the totals hold together

Before anything goes out, read the quantities as a set rather than line by line.

• Do related items agree? Formwork perimeter should be plausible against slab area; mesh sheets against slab area; excavation volume against slab plus edge thickenings.
• Are any items measured twice — once in a general area and again inside a detail region?
• Does the Bill of Quantities group items the way suppliers will quote them? A concreter, a steel fixer, and a pump hire company each want a different slice of the same takeoff.

Keep the audit trail

Export clean markups with the measured quantities so the estimate can be checked, revised, and defended if the scope changes.

When a supplier queries a number three weeks later, "here's the marked-up sheet showing exactly what was measured, on which revision" ends the conversation in one email. A takeoff whose markups live on the drawing gives you that for free: every quantity traces back to a visible shape on a named sheet. Export the marked-up set alongside the quote request and archive both together.

The 10-minute version

1. Title blocks: right revision on every measured sheet.
2. Calibration: re-verify against a written dimension per sheet.
3. Units and waste: every line has a unit; net vs gross is stated.
4. Counts reconciled against schedules.
5. Assumptions written into the request: spec, access, delivery, date.
6. Cross-check related quantities against each other.
7. Export the marked-up drawings and archive them with the request.

Do this once as a checklist and it becomes automatic — the takeoff you send is the takeoff a supplier can actually price.