Plan Check / Plan Review

Plan check — also called plan review — is the stage of the permitting process where building department staff examine an applicant's submitted construction documents to confirm they meet the adopted building, electrical, plumbing, mechanical, and zoning codes before a building permit is issued. It's the jurisdiction's verification step: the point where a reviewer reads the drawings, calculations, and site plan and decides whether the design, as drawn, complies with the rules.

In practice, plan check rarely passes on the first try. Reviewers commonly return a set of correction comments (often called plan-check comments or corrections) identifying where the submittal falls short or needs clarification. The applicant or their design professional addresses each comment and resubmits, and this cycle may repeat. How quickly and completely you respond to corrections is the single biggest factor you control over the overall permit timeline — incomplete resubmittals are a leading cause of delay.

Plan check sits between application and permit issuance, and it's distinct from the inspections that happen later during construction: plan check verifies the design on paper, while inspections verify the built work matches the approved plans. For an ADU, a clean, complete submittal is the best way to move through review efficiently — see our guide to getting a building permit for how the full process fits together. Some jurisdictions offer expedited or over-the-counter review for simpler projects, and many have streamlined ADU review specifically. Because review processes, timelines, and submittal requirements vary by jurisdiction and change, confirm your local building department's current plan-check requirements before you submit.