Our tool was counting some walls two or three times. Here's the fix, tested on the same apartment plan set

A plan set shows the same walls more than once. The floor plan has them, and so do the reflected ceiling plan, the finish plan, the enlarged unit plans, the interior elevations and the details. An estimator counts each wall once, from the floor plan. Until today, our tool counted walls on every sheet and added them together.

We found it by running a public bid set for a small university office renovation. Its 5 sheets were a partition plan, a ceiling plan, a finish plan, an elevations sheet and a door schedule. The tool reported wall footage on all five. Most of it was the same walls drawn again, plus lines inside detail drawings.

What changed

• Walls are counted on floor plans only. The tool reads each sheet's printed title. Ceiling plans, finish plans, enlarged plans, elevations, details, schedules and other trades' sheets are listed as "not counted," with the reason, right above your results.
• You can still count everything. One button, "Count every sheet anyway," brings back the old behavior. A sheet with no readable title is always counted, so nothing gets dropped on a guess.
• Wall-type legends are still read from every sheet. Legends often live on a schedule sheet, and the tool still uses them.
• One-sided walls get one side of drywall. A wall with board on one face (an exterior wall's inside face, a shaft or furring wall) used to get sheets for both faces.

Freeport Square, re-run

We re-ran the same 21-page apartment plan set from our September 22 test.

Eleven sheets were left out: the code plan, site plan, roof plan, ceiling plans, enlarged floor plans, building and interior elevations, details, and two schedule sheets. The code plan alone had added 3,252 LF and the ceiling plans 2,747 LF, all walls already counted on the floor plans.

What still isn't right

• Three unit-plan sheets in this set (A301 to A303) don't print a title where the tool looks, so they're still counted. Some of their walls may also appear on the main floor plans. Check those sheets yourself.
• 2,777 LF still needs a person to confirm the wall type, mostly masonry and exterior walls whose thickness doesn't appear in this plan's legend. The tool won't pick a type for them.
• On renovation plans, existing walls that stay are not separated from new walls yet.

We're publishing this the same way we published the real bug we found in our insulation detection: what went wrong, what we changed, and what's still open, with numbers you can check.