Verify quantities
like an estimator.
An AI takeoff earns trust the same way a junior estimator does — by passing a spot-check. Here is the workflow seasoned estimators use.
Trust, but verify in the right order
You do not re-measure every wall — that would defeat the purpose. You verify the things that, if wrong, cost the most. A disciplined estimator checks in a deliberate order: the legend, then the big rooms, then the rated corridors. Get those right and the rest of the BOQ is almost certainly sound.
The spot-check workflow
- Legend first. Confirm every wall type in the legend appears in the BOQ and is colored correctly in the classification overlays. A missing or mis-mapped type is the root cause of most quantity errors — fix it here and downstream numbers correct themselves.
- Big rooms next. The longest wall runs drive the totals. Pick the two or three largest spaces and rough-check LF times height against the SF Pilars reports. If they land close, the volume is right.
- Rated corridors and shafts. These are both the highest-stakes classifications and the highest-stakes compliance rows. Confirm they read as rated partitions in the overlays and PASS in the compliance table.
- Edge conditions. Glance at partial-height walls, furring, and anywhere two wall types meet — the spots a human would slow down on.
- Reconcile and decide. Where the overlay, legend and quantity agree, trust the number. Where they do not, that is your adjust list.
When to trust versus adjust
Trust the quantity when the wall is clearly tagged, the overlay color matches the legend, and a rough hand-check lands in the ballpark. That covers the large majority of a typical set. Adjust when the source drawing is ambiguous — a wall with no tag, a legend that reuses a color, a region of the plan that is faint or hand-marked. In those cases the model is working from poor input, and your judgment is the right tiebreaker. The skill is not re-doing the takeoff; it is knowing which handful of lines deserve a second look.
This is exactly how an experienced estimator reviews a junior's work: not by redoing it, but by checking the few things that would matter most if they were wrong. Apply the same standard to the AI and you get the speed of automation with the confidence of a manual review.
Pro tips
- Always start at the legend — most quantity errors trace to a wall type that was never mapped.
- Hand-check only the biggest rooms; they carry the most dollars and the most risk.
- Confirm rated corridors in both the overlay and the compliance table — classification and code in one pass.
- Adjust where the drawing is ambiguous, trust where it is clean — and document any line you override.
Frequently asked
Do I need to verify every quantity?
No. Check the things that cost the most if wrong — the legend, the biggest rooms, and rated corridors. If those are right, the rest of the BOQ is almost certainly sound.
When should I adjust a quantity instead of trusting it?
Adjust when the source drawing is ambiguous — an untagged wall, a reused legend color, or a faint region. Trust when the wall is clearly tagged, the overlay matches the legend, and a rough hand-check agrees.
Where do most takeoff errors come from?
Most trace back to a wall type that was never mapped in the legend, which is why verifying the legend first corrects the most downstream quantities.