Exemption Guide

Do I Need a Permit for a Ground-Level Deck?

The 30-inch rule, the 200 sq ft rule, and the cases where ground-level still needs a permit.

By Brian WilliamsPublished April 20, 2026Updated April 22, 2026

Quick Answer: A ground-level deck is usually permit-exempt if it is under 30 inches above grade, under 200 square feet, freestanding, and not in a flood or coastal zone. Attached decks, sloped-yard decks with a corner over 30 inches, and decks in strict cities always need a permit.

What “Ground-Level” Actually Means

Code doesn't use the phrase "ground-level deck" — that's homeowner shorthand. The actual code threshold is 30 inches above grade, measured from the deck walking surface down to the ground below at the deepest point within 36 inches horizontally of the deck edge.

Counts as “ground-level” for code

Deck 8 inches above flat grade
Deck 24 inches above flat grade
Deck on gentle slope where every corner is under 30 inches from the adjacent grade

Does NOT count as “ground-level”

Deck 32 inches above grade (over the 30″ threshold)
Deck on sloped lot where one corner is 36 inches above grade
Deck with a walkout-basement wall on one side (grade drops several feet)

The 8-Point Exemption Checklist

In most cities, your ground-level deck is permit-exempt only if every single one of these is true. Miss one and you probably need a permit.

1Deck surface no more than 30 inches above grade at every point
2Total area no more than 200 square feet
3Freestanding (no ledger board attachment to the house)
4Does not serve a required exit door
5Not in a flood hazard area, coastal zone, or historic district
6No electrical outlets, lighting, gas lines, or plumbing
7No hot tub or heavy load (over 50 PSF) placed on top
8HOA restrictions do not require pre-approval (HOA rules are separate from city rules)

When Ground-Level is NOT Exempt

Common situations where the ground-level exemption doesn't apply:

Attached to the house

The ledger board attachment creates a structural load path into the house. Cities want this reviewed and inspected even on low decks.

Any corner exceeds 30 inches above grade

One high corner puts the entire deck in the "guard required" category under IRC R312.1.1. Watch sloped yards carefully.

Over 200 square feet

The 200 sq ft threshold is about structural review. A 16x14 deck (224 sq ft) sitting ground-level still usually needs a permit.

Serves a required exit

If the deck is the path from a bedroom egress window or the primary exit from a finished basement, it is a means of egress. Egress is always regulated.

In a flood or coastal zone

FEMA flood-zone properties require elevation and drainage review for any structure, regardless of size.

Supports a hot tub, grill island, or outdoor kitchen

Concentrated loads over 100 PSF trigger structural review. Hot tubs also trigger electrical and plumbing permits.

In Chicago, NYC, San Francisco, Boston, and similar jurisdictions

These cities require permits for all decks, period. The ground-level exemption does not apply.

Code Still Applies Even When Exempt

Permit-exempt is not code-exempt

Even when you don't need to pull a permit, your deck still has to meet building code. That means joist spans from IRC R507.5 tables, beam sizing, proper fasteners, decking attachment, and material selection. If a guest is injured or the deck fails, you are liable regardless of whether a permit was required.

The exemption only removes the city's plan review and inspection. It does not remove your obligation to build safely.

Footings for a Ground-Level Deck

Ground-level decks can often use simpler footings than elevated decks, even when a permit is required. Common options:

Concrete deck blocks

Pre-cast pier blocks that sit on compacted gravel. Fine for low freestanding decks in areas without frost heave. Not code-accepted for ledger-attached decks or above 30 inches.

Concrete pier footings

Poured concrete in a Sonotube or similar form, extending below frost line in cold regions. The code default. Works for any deck, though overkill for a truly ground-level freestanding deck.

Helical piles / ground screws

Steel screws driven into the soil with a torque motor. Fast, no excavation, code-accepted in most jurisdictions. More expensive than concrete but practical on difficult soils or tight sites.

Frequently Asked Questions

What counts as a ground-level deck?

The working definition under IRC R312.1.1 is a deck surface no more than 30 inches above the grade below at any point within 36 inches horizontally of the deck edge. In practice, this means a deck whose walking surface sits close enough to the ground that a fall off the edge would not cause serious injury. "Ground-level" does not mean "touching the ground."

Is a ground-level deck always permit-exempt?

No. Exemption depends on your city. Most jurisdictions exempt ground-level decks that are also under 200 square feet, freestanding, and not serving a required exit. Some cities (Chicago, NYC, San Francisco) require permits for all decks regardless of height. Always verify locally.

Does a ground-level deck still need footings?

It depends. A deck under 30 inches with no attachment to the house can often sit on blocks, concrete pads, or helical piles rather than full frost-depth footings. However, if your region has deep frost or expansive soils, even a low deck may heave without proper footings. IRC R507.3 does not exempt ground-level decks from frost depth, though many jurisdictions do.

Can I build a ground-level deck attached to my house without a permit?

Usually no. The attachment to the house (ledger board) almost always triggers a permit requirement, even when the deck itself is under 30 inches tall. Cities care about the ledger because improper attachment causes more deck failures than any other issue. Most "exempt ground-level deck" provisions require the deck to be freestanding.

What if my yard slopes so one corner is higher than 30 inches?

IRC measures the 30-inch rule from the deck surface to the grade below at the deepest point within 36 inches of the edge. If any corner exceeds 30 inches, the entire deck needs a guard and a permit. Many homeowners on sloped lots think their "ground-level" deck is exempt, then find out one corner disqualifies the whole structure.

Do I still need to follow building code for a permit-exempt ground-level deck?

Yes. Permit-exempt does not mean code-exempt. Joist spans, beam sizes, fasteners, decking attachment, and material selection all still have to meet the IRC. The exemption just means no plan review and no inspection. You are still legally obligated to build to code and liable if you do not.

What is the difference between a ground-level deck and a patio?

A patio is a ground-level hardscape surface (concrete, pavers, stone) installed directly on grade or on a prepared base. A ground-level deck is an elevated wood or composite structure, typically 4 to 30 inches above grade, supported by footings, posts, or blocks. Patios have different permit rules, usually based on impervious surface limits and drainage.