What a plat of survey actually shows
A plat of survey is a scaled drawing of a property prepared by a licensed surveyor. It shows lot lines, existing structures, easements, and key measurements that reviewers use to validate setback compliance.
For accessory structures, the plat becomes the base layer for your site plan. If the plat is missing or outdated, reviewers cannot confirm where the new structure sits in relation to lot lines and easements.
Why building departments ask for it
Most rejections tied to plats are not about the drawing itself. They happen because the plat is missing, illegible, or too old to reflect current lot conditions.
- It confirms legal lot boundaries and dimensions
- It reveals easements that can block a shed or garage placement
- It helps reviewers validate front, side, and rear setbacks
- It reduces disputes when multiple structures exist on the same lot
What you can submit instead (sometimes)
Some jurisdictions allow a simpler site plan or a marked aerial map, especially for smaller sheds. Others require a formal plat of survey, especially in suburban areas.
If you are unsure, assume the reviewer will ask for the plat. It is easier to include it early than reset the timeline after a rejection.
How to avoid a plat-related delay
If you already have a plat, make sure it is legible and shows the full lot. If it is older than a few years, confirm the building department still accepts it.
Permitech flags plat requirements early and tells you when a simpler site plan is acceptable.