Reference
How to check a quantity take-off
A quantity take-off is trusted because it has been checked, not because of who or what produced it. These eight checks apply to any take-off, whether it was measured by hand, in a spreadsheet, in take-off software or by AI. How long they take depends on the drawing; the errors they catch are the ones that cost money.
Updated 13 November 2026
ScopeIs this what the drawing is for?
Decide what the take-off must cover, and for each item which drawing is the source for it. A services layout often shows walls and doors as background, and the same item can appear on several sheets. Take each item from the drawing issued to define it, and check it has not also been counted from another.
RevisionIs this the current issue?
Check the drawing number, revision and status against the register before you measure anything. A take-off from a superseded sheet is correct and useless. Record the revision on the take-off so the next change can be measured against it.
ScaleIs the scale supported by the sheet?
Printed dimensions and levels come first. If you scale, confirm the scale against a printed dimension or a scale bar on the same view: a PDF printed to fit, or a view at a different scale from the title block, will measure wrongly without looking wrong. Where the drawing says “Do not scale”, treat that as an instruction: do not use a scaled measurement as a dimension to build or order from. Get the figure from the printed dimensions, or confirm it with the drawing’s author.
Counted onceIs each physical item counted once?
The same item is often drawn on several views and labelled more than once. Count the thing, not the labels. Tags help: a unique tag is one item however many times it appears, while a type reference repeated on twenty doors is twenty doors. Grid bubbles, section marks and numbered notes are not items at all.
Gross or netHave openings been deducted?
An area of wall is either gross, with openings measured through, or net, with them taken out. Both are legitimate; mixing them is not. Say which each area is, and follow the measurement rules the job is priced under for which openings are deducted.
Units and what is measuredIs it the right unit for this item?
A membrane is an area, a barrier is a length, a door is a number. An item measured in the wrong unit cannot be priced or ordered. Check too that the quantity is of the component named: a plinth course is not the wall above it.
What is defined elsewhereWhat does this sheet leave to another document?
“See schedule”, “refer to structural engineer’s drawings” and “to be confirmed” all mean the quantity or the specification is not on this sheet. List them. A gap that is written down gets chased; a gap that is silent gets priced at nothing.
The recordCould someone else find where each number came from?
Keep each quantity with its location on the drawing and how it was measured. It is what lets you check a take-off in minutes, defend it when it is questioned and update it when the drawing is revised.
Measurement rules
These checks are about whether the quantities are right. How building work should be measured and described for pricing is a separate matter, set by the measurement rules the job uses. RICS NRM 2, Detailed measurement for building works, is one recognised method for building work in the UK; its second edition was published in October 2021 and took effect on 1 December 2021. CESMM4 is commonly used for civil engineering work. Use the method, and the edition, that the job specifies.
RICS NRM 2: Detailed measurement for building works, 2nd edition (PDF)
A take-off built to be checked
The free tool on this site marks the items it finds on the drawing, says how each was measured, keeps quantities that passed its checks apart from candidates and lists what it noticed the sheet leaves to other documents. It is in development and will miss things, which is what these checks are for. See an example, or use it on your own drawing.
Take off a drawing