Do You Need a Site Plan for a Patio Permit?

Published 2026-07-12 · Reviewed by Todd Hartman

Here is the short answer: if your patio needs a permit, the application needs a site plan, and even the patios that skip the permit face a zoning check most homeowners have never heard of. For a project people describe as "just a slab," an awful lot of the review happens on the drawing.

The patio paradox

Ground-level, uncovered patios are the friendliest project in permitting, often exempt from building permits entirely, and the patio permit guide covers where that line sits state by state. So why do patio applications still ask for a drawing? Because what a patio changes is not structural, it is hydrological. Every square foot you pave changes how much of your lot sheds rainwater instead of soaking it up, and cities regulate exactly that.

Impervious coverage: the check nobody expects

Many cities cap the percentage of a lot that can be covered by impervious surfaces: roofs, driveways, walkways, pool decks, and most patios. When your application lands, the reviewer takes your lot's square footage, adds up everything already paved or roofed, adds your proposed patio, and checks the total against the cap.

All of those numbers come from your site plan. This is the detail that separates a patio site plan from other projects: the drawing has to show your existing hardscape, not just the new slab, because the math is cumulative. Leave the driveway and walkways off the plan and the reviewer either sends a correction notice or, worse, approves against numbers that a later inspection contradicts.

What the patio site plan has to show

The patio footprint, to scale, with dimensions and total area labeled, since fees and review paths often key off the square footage
Setbacks from the patio edge to your property lines, which apply even where the building permit does not
The relationship to the house, drawn clearly, because uncovered flatwork and an attached covered patio are reviewed under different rules
Existing paved and roofed surfaces, so the impervious-coverage math works
Easements and drainage: the patio must stay out of recorded easements, and the grading should not aim runoff at your neighbor's lot
The basics block: north arrow, scale, parcel number or address

If your patio has a roof

One word changes the whole review: cover. A roofed or enclosed patio is a structure, and it needs a permit almost everywhere, including cities that exempt every slab. The site plan stays the anchor document, now showing the cover's footprint and whether it is attached or freestanding, with the structural details on accompanying building plans. If that is your project, start from the patio permit guide so the permit side does not surprise you, and expect the site plan to be non-negotiable.

Getting the drawing

The drafted route: patio site plans run $89 to $259, delivered in 24 to 48 hours, drawn to scale from county GIS records and satellite imagery with the footprint dimensioned, setbacks labeled, existing hardscape shown for the coverage math, and free revisions until your city accepts it.

The DIY route suits a simple lot and a city that accepts hand-drawn plans: the six-step walkthrough shows the method and the Pre-Submission Checklist is the final gate. The patio-specific discipline is measuring and drawing the surfaces you already have, because that is the part reviewers actually recalculate.

Before you pour

Concrete is the least movable mistake in the yard, so settle the placement on paper against your real property lines, not the fence line. Then spend two minutes on your city's checklist: some departments add grading or drainage notes for larger patios, and coastal and floodplain areas add their own. For everything about the drawing itself, the complete guide to site plans for permits goes deeper on each element above.

Frequently asked questions

Do I need a site plan if my patio does not need a permit?

Often it is still the smart move, and sometimes it is still required. Zoning setbacks and lot coverage caps apply to exempt patios too, and some cities run a zoning review with a simple site plan even when no building permit applies. Since concrete is the least movable mistake in the yard, checking the placement on paper before the pour costs five minutes and saves demolition.

What is impervious coverage and why does it matter for my patio?

Impervious coverage is the share of your lot covered by surfaces that shed water instead of absorbing it, like roofs, driveways, walkways, and most patios. Many cities cap that percentage to manage stormwater, so the reviewer adds your new patio to everything already paved and checks the total. It is the patio check homeowners least expect, and your site plan supplies the numbers for it.

What does a patio site plan need to show?

Property lines with lot dimensions, the house and other structures, the patio drawn to scale with its dimensions and total square footage labeled, setback distances from the patio edge to the property lines, existing paved surfaces so coverage can be calculated, any easements, and the basics block of north arrow, scale, and parcel number.

Does a covered patio need a different site plan?

The base drawing is the same, but the cover raises the stakes, because a roofed patio is a structure that needs a permit almost everywhere. The plan must show the cover's footprint and make clear whether it is attached to the house or freestanding, and the posts and attachment details go on the building plans that accompany it.