PreConstruct AIHow to check us
We don't publish an accuracy percentage
Everyone else in this category does, and none of them says what it was measured on. So here is the thing that is actually worth having instead: every formula the software uses, run on a wall, with the working printed. Check it against a job you have already bid. It takes about two minutes.
The worked example
One wall, and everything it buys
A 20′ × 10′ partition with one 3′-0″ × 7′-0″ door, built as interior partition — 3-5/8" metal stud, 5/8" board both sides. Every line below was produced by the same code that runs when an estimator sends a wall to their takeoff. Nothing on this page was typed in by hand.
First, the areas
- One face, before the door
- 200 SF
- Both faces, before the door
- 400 SF
- The door
- 21 SF
- Both faces, door removed
- 358 SF
A hole goes through a wall, so it comes off twice. Board, tape, compound and paint buy the net figure; framing buys the gross, because the studs around an opening are not saved.
- 3-5/8" 25ga metal stud22EA
20 LF × 12 ÷ 16" = 15, + 1 = 16 + 1 opening × 4 = 20 × 10% waste → 22
- 3-5/8" 25ga track44LF
20 LF × 2 = 40 × 10% waste → 44
- 5/8" Type X gypsum board, 4×813SHT
358 SF net both faces × 10% waste ÷ 32 SF/sheet = 12.3 → 13 sheets
- 3-1/2" acoustic batt2PKG
179 SF net one face × 5% waste = 188 SF ÷ 105.6 SF/pkg = 1.8 → 2
- Joint tape146LF
358 SF board ÷ 100 × 37 LF × 10% waste = 145.7 → 146
- Joint compound6GAL
358 SF board ÷ 100 × 1.4 gal × 10% waste = 5.51 → 6
- Latex primer2GAL
358 SF × 1 ÷ 350 SF/gal × 5% waste = 1.07 → 2
- Eggshell latex3GAL
358 SF × 2 ÷ 350 SF/gal × 5% waste = 2.15 → 3
If any of those lines disagrees with what you would have bought, the number to change is in your own wall type, not in our code. Every rate above is a field on that screen.
Where the rates come from
Ordinary trade figures, and all of them yours to change
These are the starting values. They are conventional, not authoritative, and the software has no opinion about whether they are right for your crews or your suppliers.
| What | Starting value |
|---|---|
| Studs | every 16″, plus one, plus 4 at each opening |
| Track or plate | 2 runs the length of the wall |
| Board | 32 SF a sheet, 2 sides, 1 layer |
| Insulation | 105.6 SF a package, one face |
| Joint tape | 37 LF per 100 SF of board |
| Joint compound | 1.4 gal per 100 SF, three coats |
| Primer and paint | 350 SF a gallon, 1 primer coat and 2 finish coats |
| Waste | 10% framing, 10% board, 5% insulation, 10% finish, 5% paint |
What we have measured, and what we have not
The uncomfortable half
What we can show you
- The arithmetic above, which is the code, not a description of it.
- Every figure the software reads carries the sheet, the page and the spot on it. The database refuses a figure without one, so no path through the product can produce a number that looks checked and is not.
- Where a drawing states no quantity, the field stays empty and the row is flagged. A number is never invented to fill a gap.
- Nothing reaches a bid unreviewed. Everything the software produces lands in a review state and becomes live project data only once you have confirmed, edited or rejected it.
What we cannot yet
- No wall takeoff has been checked against an estimator's own hand takeoff. The arithmetic is tested to the last decimal; whether it matches what you would have bought is a different question and we have not asked it yet. That is what the founding customers are for.
- We have no verified accuracy figure of any kind, which is why there is not one anywhere on this site. When we have one that a person has checked, it will appear here with its method beside it.
- The software reads text, not pictures. It will not trace a partition or count a symbol on its own, and it does not do electrical or plumbing takeoffs at all.
- Scanned sheets go through character recognition, and every number read from a scan is flagged for you rather than trusted.
Two minutes
Check it against a job you already bid
- 1. Take a wall off a job you have already built. You know what you bought.
- 2. Put its length and height into the arithmetic above. Board is net area over sheet size, times waste.
- 3. Compare. If we are out, you will see exactly which line and exactly which rate did it, because every line shows its own working.
That is the whole test, and you can do it without signing up or sending us a drawing. If it holds, the first bid is free.