A takeoff (quantity takeoff) is the estimator’s job of “taking off” quantities from the drawings and specs: linear feet of wall, square feet of drywall, cubic yards of concrete, counts of doors, fixtures and devices. Quantities are organized by scope, often by CSI MasterFormat division, then multiplied by unit costs for labor, material and equipment to produce the estimate. Takeoffs are done on paper, in digital on-screen tools, or from BIM models.
Why it matters
Everything downstream depends on the quantities. A missed scope or bad count becomes a bust in the bid, then a budget problem, then margin fade. A good takeoff organized by cost code also becomes the starting budget, so the field and the office measure the job the same way.
Worked example
Illustrative: on a job like Riverside Medical Center, the estimator counts fire dampers from the mechanical drawings during bidding. If the drawings don’t show dampers at a rated wall (as RFI-212 later revealed), the takeoff misses them. That is a design gap, recoverable through a change order (CO #14, $86,400), but the same type of miss on a contractor’s own scope would be unrecoverable.
Common mistakes
- Takeoff organized differently from the cost codes the job will be tracked on.
- Not reading the specs, only the drawings.
- No waste factor, or the same waste factor for every material.
How os.construction handles it
We’re building estimate and budget lines that share cost codes with job costing, so takeoff quantities can carry into the budget and be compared to actual production later.