Lumber takeoff checklist: 12 checks before the list goes out
Most takeoff errors are not math errors. They are a sheet at the wrong scale, a wall type nobody counted, a header that is missing. These twelve checks catch most of them, whether you made the takeoff, a colleague did, or an AI drafted it.
Why check a takeoff at all
Run the checks with the plan set open beside the list. The goal is to account for everything on the plans once, and nothing twice.
A takeoff that is a few percent off on studs costs a little. A missed floor, a wrong-scale sheet or a roof taken off the footprint instead of the slope costs a return trip, a short order or a quote that does not hold.
Checking is also how you build trust in someone else’s takeoff. If you can’t see where a number came from, you end up redoing it. That is why a takeoff should show its work: which lines on which sheet, and which rule turned them into pieces.
The 12 checks
1. Every sheet is in the set
Floor plans for every level, elevations, sections, and the framing or structural sheets. A missing basement or bonus-room sheet is a missing floor.
2. Every sheet is at the right scale
Measure one known dimension on each sheet. Sets often mix scales, and enlarged details are the usual culprit.
3. Every wall type is counted
Exterior, interior bearing, partitions, plumbing walls, knee walls. Compare the list’s wall types against the legend and the wall sections.
4. Plate heights match the sections
Stud lengths follow plate height. Check each floor, plus any vaulted or stepped ceilings.
5. Every opening has a header
Count openings on the plan, not just the schedule, and confirm each one has a header sized for its span plus king and jack studs.
6. Corners and intersections are covered
Extra studs or backing at every corner and every place a wall meets another. Easy to skip, adds up fast.
7. Floors match the joist layout
Joist direction, span, size and spacing per area, rim board around the perimeter, beams and blocking where called for.
8. The roof uses the sloped area
Rafters and roof sheathing come from the roof plane, which is larger than the footprint. Check pitch on every plane.
9. Sheathing deductions follow one rule
Whatever you deduct for openings, apply it the same way everywhere and write it down.
10. Nothing is counted twice
Overlapping areas, a wall drawn on two sheets, a floor counted on both the plan and an enlarged detail.
11. Waste is visible and per assembly
A blanket percentage hides problems. Waste per assembly, shown on the list, can be reviewed and adjusted.
12. The list maps to real products
Every line is a size, grade and length you stock or can order, and nothing is left as a raw linear-foot total.
How Aximos helps with the checks
- 01
Every number shows its work
Click any quantity on the list to see the traced lines on the plan and the formula behind it. Checks 3–10 become looking, not re-measuring.
- 02
Built-in QA/QC checks
The workspace flags common misses, such as an opening with no header, so you start the review from a list of things to look at.
- 03
Assumptions cite the sheet
When the AI makes an assumption, it says which sheet and note it came from, so you can confirm or change it in one place.
Takeoff QA/QC questions
What is takeoff QA/QC?
Quality assurance and quality control for a takeoff: checking that every part of the plans was counted once, at the right scale, with the right rules, before the list is quoted or ordered.
How long should checking a takeoff take?
Much less than making it, if you can see where each number came from. If you can’t, checking turns into redoing. That is the main reason Aximos ties every quantity to its trace on the plan.
What are the most common lumber takeoff errors?
A sheet at the wrong scale, a wall type or floor that was never counted, missing or undersized headers, roof quantities taken from the footprint, and areas counted twice. Checks 2, 3, 5, 8 and 10 cover them.
Do I need to check an AI-generated takeoff?
Yes. Aximos first drafts are typically 80–95% accurate to final quantities, so a review is part of the workflow, not an afterthought. The review happens in the same workspace, with the plan, the traces and the list side by side.
Check a takeoff instead of redoing it
Bring a plan set. We run the AI draft with you and walk through the checks on your own plans.