Comparing two drawing sets by hand is one of the least glamorous tasks in preconstruction, and one of the most expensive to get wrong. Novo Construction handed it to software.
The Menlo Park, California general contractor has deployed Diffs, a feature of the AI drawing-review platform BuildCheck, on two active California projects. The tool compares successive drawing sets automatically and flags what moved: walls, added windows, door swaps, dimensional changes.
What it replaces
The old workflow is overlay comparison in Bluebeam, page by page, across sets that routinely run into the hundreds of pages. Novo chief information officer Colin Stoner described the manual version to Construction Dive as work that made you go cross-eyed.
That description is doing real work. Manual overlay review isn’t hard, it’s long, and the failure mode isn’t misjudgment. It’s fatigue. A reviewer on page 240 of a 300-page set catches less than the same reviewer on page 12, and the changes that slip through are the small dimensional ones that surface later as field conflicts.
Where it pays
Stoner’s framing is that this belongs in preconstruction, and that’s the part worth taking seriously. A drawing change caught before construction starts is a pricing conversation. The same change caught in the field is a change order, plus whatever’s already been fabricated.
The tool doesn’t decide anything. Stoner describes the workflow as trust but verify, with the software flagging candidates and project managers reviewing them. That’s a narrower claim than most construction AI marketing makes, and it’s a more defensible one: the model is doing detection, not judgment.
The adoption question
What separates this from the usual vendor announcement is that a real general contractor is running it in production on named projects rather than piloting it. That’s still rare. Most AI drawing-review tools live in demos.
Two projects isn’t a rollout, and Novo hasn’t published time savings or a caught-error count. Without those numbers the case rests on the mechanism rather than the evidence, and contractors evaluating this category should ask for the evidence.
Detailed drawing comparison matters most on renovation and repositioning work, where the existing-conditions set and the design set diverge constantly. Projects like the Chrysler Building repositioning run years of phased drawing revisions against a landmark envelope.
Source: Construction Dive, Aug. 5, 2026.