What Is a Site Plan for a Deck Permit?

A site plan is a drawing of your property from above, showing the lot boundary, the house, the proposed deck, and how far the deck sits from each property line. It is the sheet the zoning side of the office reads, and it answers a different question from the rest of the set: not whether the deck is built correctly, but whether it is allowed to be where you want to put it.

What is usually on it

The property lines with their dimensions, the house footprint, the proposed deck with its dimensions, the distance from the deck to the front, side and rear property lines, the street, and a north arrow. Existing structures such as a garage, shed, driveway or pool are commonly shown too, because some jurisdictions limit how much of a lot may be covered.

Setbacks are the usual sticking point

A setback is the minimum distance a structure must sit from a property line. Setbacks come from your local zoning district, not from the building code, and they differ from town to town and sometimes between districts in one town. A deck that crosses one needs a variance, which is a slower and less certain process than a permit.

This is worth checking before you build anything on paper. Moving a deck two feet is free while it is a drawing.

Where the numbers come from

The reliable source is a property survey, which shows the boundary and its dimensions as measured. Failing that, county parcel records carry the lot shape, and your zoning department can tell you the setbacks for your district. What you should not do is estimate them: a site plan is a set of assertions about your property, and a wrong one is worse than a missing one because the reviewer has no way to know it was a guess.

When you run your own address on this site, the lot shape and the parcel record come from public records and the setbacks are yours to confirm, because those are the numbers we cannot look up for you with confidence.