Where we are
Counting first. Still learning to measure.
Quantity take-off has gone from an unreliable read of a whole drawing to a take-off you can check line by line, and it is strongest at counting items that carry a tag. It is not finished. This page says what it does today, what it does not, and what we are doing about it.
Updated 13 November 2026
What we are aiming for
A schedule of quantities you can review quickly, with the evidence behind every number. It should take off what the drawing is for, count each physical item once, measure from a scale the sheet supports, and keep anything it is unsure of in plain view. The test is simple: does checking it take clearly less of your time than doing the take-off yourself?
What it does today
Counting tagged itemsMost developed
Doors, windows, equipment and devices that carry a printed tag are found from the tag, checked against the symbol on a close-up at full resolution, and counted once. Each one is marked on the drawing.
Still to do: On the set of drawings we test against, most printed tags are found and counted once. We have seen a tag attached to the wrong symbol and a grid reference read as a door, so check for missed, duplicated and wrongly identified items.
Taking off what the drawing is forMost developed
The sheet is read first for its discipline and purpose. A security layout is taken off for security equipment, and the walls and doors drawn as background are left out.
Still to do: Proved on a subset of sheets. Unusual sheet types may be scoped too widely or too narrowly.
Scale and “Do not scale”Most developed
Scale is taken from what the sheet prints: levels, scale bars and stated scales, checked against each other. A scale nothing on the sheet supports measures nothing, and a sheet marked “Do not scale” says so on every measured quantity.
Still to do: Sheets with several views at different scales are handled view by view and are undergoing further testing.
Showing the evidenceMost developed
Every line says how it was identified, where it is, how it was measured and what is still unresolved. A quantity that fails a check is kept and shown as a candidate, and never added to an accepted total.
Still to do: The reasons are written by the software and can be terse.
Lengths and areasFor checking
Runs and surfaces are traced and measured, and offered as candidates with the reason each one was held back, such as a trace that leaves the drawn lines or openings that are not deducted.
Still to do: This is the weakest part. On our latest test runs no length or area passed its own checks, so none passes automatically. Treat every one as a starting point to measure against.
Items with no tagNot yet
Some untagged items are found from the legend and their symbol.
Still to do: We cannot yet show that all of them are found, so an untagged count may have omissions.
Scanned and image-only drawingsNot yet
A scan or photograph is accepted and taken off from the image alone.
Still to do: Much of the checking relies on the text a CAD-exported PDF carries. Without it, fewer checks run, so scanned drawings are likely to be less accurate.
What we cannot tell you yet
We do not have an accuracy figure. The tool has been repeatedly tested on a subset of drawings we know well: a security layout, a ventilation layout and two sets of elevations. That tells us where it goes wrong. It does not tell us how often it is right on a drawing it has never seen, and a correct total can hide a missed item cancelled out by a false one. Until it has been scored against drawings marked up by hand, treat every quantity as one to check.
What we are doing next
Stop annotations being counted
Grid references, callouts and notes must never become items, whichever route they are read by. This is the first fix.
Measure it on drawings we have not seen
So far the tool has been tested on a few drawings we know well. Our next step is to score it against multiple unfamiliar sheets from different authors and disciplines, with the right answers marked up by hand first. Drawings uploaded here are part of that.
Get lengths and areas from the right geometry
Find the correct boundary of a wall, a run or a surface from the drawing’s own line work before measuring it, so a length or an area can be accepted and not only offered.
Prove it saves time
Test the whole job with people who take off quantities for a living: review, correct, accept and export. The measure is whether they reach a schedule they would rely on faster than their usual way.
How we will know it is good enough
- Every quantity can be found on the drawing.
- No note, grid reference or callout is counted as an item.
- Each physical item is counted once, however many times it is drawn or labelled.
- Lengths and areas use the right component, scale and unit, and say whether they are gross or net.
- What could not be assessed is listed, so a gap is never mistaken for a zero.
- Checking the take-off takes clearly less time than doing it from scratch.
How you help
Every drawing taken off here is one more way a drawing can be drawn, and that variety is exactly what the tool has not seen enough of. Marking a line right or wrong on your result gives us an answer checked by someone who knows the job. That is why the tool is free, and why we keep your drawing for 90 days.
Take off a drawingChanges
Clarified what testing has and has not shown
The progress account now distinguishes the drawings tested repeatedly from the wider drawings still to be scored, and says that scans have fewer checks and are likely to be less accurate.
Checked quantities and candidates are kept apart
A quantity that has been calculated is no longer treated as one that passed its checks. Candidates stay out of the totals, and each family of items reports what was and was not covered.