Blog · September 27, 2026
What Is a Building Line on a Plat
A building line is a line on the plat beyond which the main structure may not extend.
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It can be stricter than a zoning setback. It is drawn parallel to a lot line or a right of way and labeled with a distance.
On the recorded sheet
Porches and eaves may or may not be allowed over it. The plat note is the first place to read that exception.
The mix-up to avoid
A zoning variance does not erase a building line that was recorded on the plat.
Find the county map
Start at Platbookmapper, search the county, and open the local GIS link. Write down the parcel number before you compare the screen to a paper plat.
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey.