Why there is no AI in our take-off tool

14 October 2026

Every software catalogue now promises that the drawing will measure itself. It is a good demonstration. It is a bad position to be in when the tender is due on Friday.

The failure that matters

Automatic interpretation does not fail by crashing. It fails by returning 412 square metres when the answer was 480: a number of the right shape, in the right column, with nothing about it that looks wrong. You find out when the work is on site and the plaster runs out.

An estimator can catch a crash. Nobody can catch a plausible number without doing the take-off again, which is the thing the tool was supposed to save.

What QTac does instead

It measures what you point at. You trace the slab; it gives you the area. You tell it the thickness; it gives you the volume and shows the arithmetic. If the figure is wrong, it is wrong because the drawing or the parameter was wrong, and both of those are on the page in front of you.

For CAD drawings there is a middle road: map a layer to an item and QTac measures every entity on that layer. That is not interpretation, it is instruction. You still confirm what was found, and a validation pass reports open polylines, zero-length entities, duplicates and anything outside the sheet border before a single quantity is produced.

The test we hold ourselves to

Every quantity in the output must be traceable back to a measured entity on a specific sheet.

That line has been in our specification since the first day, and it is the reason the Working column exists, the reason the marked-up PDF exists, and the reason there is no button that measures the drawing for you.

Automation that you cannot check is not a saving. It is a liability you have not been billed for yet.