The mechanical sheet still carries a background from three revisions ago. A fixture count on the plans disagrees with the schedule. A section callout points at a detail that was renumbered two issuances back. None of these are exotic. All of them reach the field as rework.
Ask a VDC coordinator how it happened and the answer is never that nobody looked. It's that looking doesn't scale. Architectural against mechanical, mechanical against structural, structural against plumbing, sheet by sheet, by eye. Then a revision lands and the whole pass is stale. The set is too big to check the same way twice, so the second pass is shorter than the first, and the third is shorter than that.
Why the gap survives
Model-based clash detection is good at what it does, and what it does is check the model. Plenty of projects never produce a fully coordinated one. On the projects that do, the contract documents are still the issued 2D sheets, and the trades build from those. Drawing schedules, callout chains, title blocks, and embedded backgrounds don't exist in the model at all. They only exist on the sheets.
So the most consequential construction drawing coordination work on a job is still done by hand, against a document set nobody automated, by the person with the fewest spare hours.
What we built
TrunkCoordinate registers sheets from every discipline onto one coordinate frame. Once architectural, structural, and MEP share a frame, an object at one point on one sheet can be compared against whatever sits at the same physical location on another. From there it reconciles three things.
Objects across disciplines. The same object resolved to a single entity wherever it appears, then compared trade to trade for count, location, type, and tag. Where two disciplines claim the same spot on the same plane, that's one finding carrying every trade involved, not a stack of pairwise ones.
Schedules and references. Objects on the plans with no schedule row, and schedule rows with nothing on the plans. Blank or TBD cells flagged instead of passed through. Callouts followed to the sheet they point at, so a renumbered or deleted detail gets caught.
Set integrity. Every embedded background compared against the current architectural source of record, so walls that moved on one set don't quietly stay put on another. Title blocks and the sheet index reconciled both ways.
Every finding carries its source sheets, the objects involved, and an impact rating. Findings push out as RFIs, coordination issues, or change events, and they keep their identity across revisions, so a re-run on a new issuance builds on prior triage instead of starting over.
Where it sits
TrunkReview finds what changed. TrunkCoordinate finds what that change broke. TrunkChange finds who pays.
TrunkCoordinate is in development, and we're previewing it at Autodesk University this week. We'll publish performance numbers when we've measured them, not before. If you want your set among the first we run it against, tell us.
Frequently asked questions
What is construction drawing coordination? Construction drawing coordination is the process of comparing architectural, structural, and MEP sheets to find conflicts in object locations, counts, types, tags, schedules, references, backgrounds, and set information before those conflicts reach the field.
Why is model-based clash detection not enough? Clash detection checks the model, but the issued 2D sheets remain the contract documents on many projects. Schedules, callout chains, title blocks, and embedded backgrounds may only exist on those sheets, so they require their own coordination review.
What does TrunkCoordinate check? TrunkCoordinate compares objects across disciplines, reconciles plans with schedules and callout references, checks embedded backgrounds against the current architectural source, and compares title blocks with the sheet index.
How does TrunkCoordinate handle drawing revisions? Each finding keeps its identity across revisions, so a new run builds on the team's prior triage instead of forcing coordinators to restart the review.
How is TrunkCoordinate different from TrunkReview and TrunkChange? TrunkReview finds what changed between drawing versions. TrunkCoordinate finds what that change broke across the document set. TrunkChange helps determine who pays for the resulting scope.
By the Trunk Tools team. Published September 15, 2026.