Quantity takeoff is the process of measuring exactly how much of each item a job actually needs, straight off the drawings, before any rate gets applied. It sounds like the mechanical part of pricing a job, but it's the part that determines whether everything built on top of it is any good.
Ask a room of builders what is quantity takeoff and most will say "measuring up". That's right, as far as it goes. What it misses is that the takeoff is also where you decide what the job contains. Anything not measured doesn't get priced. Anything measured twice gets paid for twice, by you or the client.
What is quantity takeoff, in plain terms?
You take the drawings and specification and turn them into a list of items with quantities against them. Concrete in foundations. Area of blockwork. Length of skirting. Number of internal doors. Every item described clearly enough that someone pricing it knows what they're pricing.
That list is the bridge between the design and the money. The architect draws the building. The takeoff turns the drawing into things you can buy, hire and pay people to install.
And it gets used more than once. The same quantities feed your estimate, can be set out as a bill of quantities for subcontractors to price against, give you a material list for ordering, and later become the reference for measuring work done at each valuation. So when someone asks what is quantity takeoff for, the fair answer is: nearly everything that involves money on the job.
That's also why it's worth doing once, properly, rather than three times in a hurry. A rough measure for the tender, another for ordering and a third when the valuation is disputed is more work than a single takeoff done right, and the three versions rarely agree with each other.
What gets measured, and how
Different items are measured in different units, and getting the unit right matters as much as getting the number right.
- Volume (m3). Excavation, concrete in foundations and slabs, hardcore fill.
- Area (m2). Walls, floors, ceilings, roof coverings, plastering, decoration.
- Length (m). Skirtings, pipework, gutters, kerbs, cavity closers.
- Number (nr). Doors, windows, sanitaryware, lintels, light fittings.
- Weight (t or kg). Reinforcement and structural steel.
In the UK, the standard for how building work is measured and described is NRM2 from RICS. Measuring to it means your quantities line up with how the job will eventually be valued on site, and anyone reading them knows the rules you followed. A takeoff that uses its own rules might add up, but it's harder to check and harder to defend.
Manual measurement versus on-screen tools
Takeoff can be done manually against printed drawings or using on-screen measurement software against digital drawings. Software speeds up the process and reduces transcription errors, but it doesn't replace the judgement needed to read a drawing correctly in the first place. The software will happily measure the wrong wall if you click on it.
On the contractor side, takeoff is usually done by an estimator or a quantity surveyor working from issued drawings and specification, not by whoever produced the drawings. The person measuring needs to understand how the job will actually be built, which is why it sits with the pricing side of the business rather than upstream of it.
From drawings to a usable breakdown
Takeoff isn't just a list of numbers. It has to be organised by element so it can feed straight into a cost plan or an estimate without being reworked. Measure it loosely and someone else has to redo the organising work before it's any use for pricing.
A small example shows why. Say a wall on plan is 5 m long and 2.4 m high, with a window 1.2 m by 1.2 m. The gross area is 12 m2, the window is 1.44 m2, so the net wall is 10.56 m2. But a proper takeoff doesn't stop there. The window itself, the lintel over it, the cavity closers round it (roughly 4.8 m around the opening) and the sill are each separate items. The quick measure gets the wall. The proper takeoff gets everything the wall needs.
A good takeoff can also be turned into a material list for suppliers. If that's mainly what you need, see material takeoff services for builders.
Nothing gets priced that wasn't measured first. The takeoff is where your price is won or lost, long before any rate goes in.
Where takeoff goes wrong
The most common error isn't a wrong measurement. It's measuring against an old drawing revision, or missing an item because it was only shown on one drawing out of several. Cross-checking drawings against each other before finalising quantities catches most of these before they turn into a priced mistake.
Other regular culprits:
- Scale not checked. A PDF printed or opened at the wrong scale throws off every dimension taken from it.
- Openings not deducted, or deducted twice. Both happen, especially when two people measure the same area.
- Items on details only. Flashings, cavity trays, fire stopping and trims that appear on a section but nowhere on the plan.
- Specification ignored. Measuring "insulation" without checking the thickness and type the spec actually calls for.
A quick check on any takeoff
Take the gross internal floor area from the plans and hold it against the floor finishes, ceilings and skirting in the takeoff. They should broadly agree once you allow for things like tiled areas or rooms without skirting. If they don't, something has been missed or doubled, and it's worth finding before a single rate goes in.
Get the takeoff wrong and every number built on top of it is wrong too. If you'd rather hand the measuring over, our quantity takeoff services UK contractors use measure every element off your drawings to NRM2, for a fixed fee agreed up front.