Features
Everything you need. Nothing you don't.
Purpose-built for construction plan annotation and collaboration. Not another generic PDF tool.
Annotate
Stamps, connectors, text, shapes, freehand, measurements, and a quantity table that tallies automatically.
Learn moreCollaborate
Share with a link. No app, no account. Fine-grained permissions, structured review rounds, and checklists.
Learn moreSign Off
Compare changes, resolve conflicts, and get formal mutual sign-off with timestamps and an exportable audit trail.
Learn moreQuote
Build quotes directly from your annotations. Material and labour split, measurement-linked quantities, shareable quotes.
Learn moreReady to ditch the notepad?
Join builders and tradies who are already using CoBuild to annotate plans, share with clients, and get sign-off — all in one place.