CivilPlanAI is an AI-powered QA/QC platform built specifically for civil engineering firms. A civil plan set is uploaded and four specialized AI reviewers each check every sheet from a different angle; grading and drainage, standards and code, drawing quality, and cross-sheet coordination. It uses a vision model that reads the actual linework, callouts, and elevations rather than just a text layer, and where the drawing states its own numbers it pulls the inverts and run lengths off the sheet and does the arithmetic. Before it starts, a research agent works out which jurisdiction has authority over the project and which codes each has adopted, so the review is measured against local standards, not a national average. Every finding is pinned to a sheet and location with a code reference and a confidence level, and cross-checked to cut false positives. A full review runs in minutes versus the roughly 4–8 hours a manual QA pass takes. The engineer of record stays the final word. CivilPlanAI drafts findings; the engineer approves, edits, or rejects each one, and it never stamps anything. Customer plan data is not used for training and is not shared.