Deck permits

What the model code says

Most U.S. cities and counties base their residential rules on the International Residential Code (IRC), published by the International Code Council. The current edition is the 2024 IRC. Many places still enforce the 2021 or an earlier edition, and almost all of them amend it, so treat the following as the starting point rather than the final word.

When a deck is exempt

Section R105.2 lists work that does not need a permit. For decks, the 2024 text reads:

Decks not exceeding 200 square feet (18.58 m2) in area, that are not more than 30 inches (762 mm) above grade at any point, are not attached to a dwelling or townhouse and do not serve the exit door required by Section R318.4.

All four conditions have to be true:

• Size: 200 square feet or less.
• Height: the walking surface is no more than 30 inches above grade at any point. On a sloping yard, measure at the lowest grade, not the average.
• Freestanding: not attached to the house or a townhouse. A deck bolted to the rim joist or ledger fails this test.
• Not the required exit: the deck is not the landing for the home’s required egress door. If the door it serves is the house’s one required exit, the deck is part of the exit path and needs review.

The 2021 IRC used nearly the same wording but said “not attached to a dwelling” and cited Section R311.4. The 2024 edition added townhouses and renumbered the egress section.

R105.2 also says that being exempt from a permit “shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances.” An exempt deck still has to be built to code and still has to meet zoning rules.

Key construction rules inspectors check

The IRC’s prescriptive deck rules are in Section R507:

• Footings (R507.3). Decks must sit on concrete footings or another approved system. Footings must be at least 12 inches below undisturbed ground (R507.3.2). Where the deck is attached to a frost-protected house, footings must extend below the local frost line or be otherwise frost-protected (R507.3.3). Your jurisdiction’s frost depth is in its local design criteria (IRC Table R301.2).
• Attachment (R507.8 and R507.9). An attached deck must be “positively anchored to the primary structure,” and the attachment “shall not be accomplished by the use of toenails or nails subject to withdrawal.” If the inspector cannot verify a positive connection, the deck must be self-supporting. Ledgers must be at least 2×8 nominal, cannot be hung on stone or masonry veneer, and need flashing that extends at least 2 inches above the ledger. Lateral-load hold-downs (R507.9.2) are required in specific configurations.
• Materials and fasteners (R507.2). Treated lumber, composite boards, and connectors must meet the listed standards. Corrosion-resistant fasteners matter because treated wood is corrosive to plain steel.
• Guards (R321). Required on open sides more than 30 inches above grade within 36 inches of the edge. The minimum height is 36 inches, and openings must not pass a 4-inch sphere.
• Stairs (R318.7). Stairs need a clear width of at least 36 inches, risers of no more than 7¾ inches, treads of at least 10 inches, and a handrail on at least one side where there are four or more risers.

Zoning, HOA rules, and setbacks

A building permit answers “is it safe?” Zoning answers “is it allowed here?” Even an exempt deck usually has to respect:

• Setbacks. Minimum distances from property lines. Many zoning codes treat a raised deck as part of the house for setback purposes, while a grade-level patio may be allowed closer to the line.
• Lot coverage or impervious-surface limits. Some codes count decks, others do not.
• Easements. Utility and drainage easements often prohibit permanent footings.
• Historic districts and HOAs. Design review and private covenants are separate from the building permit. An HOA approval does not replace a permit, and a permit does not override HOA rules.

Ask the zoning or planning desk for the setback that applies to your lot before you draw the deck. A survey or plat showing property lines makes that conversation faster.

Permits and inspections you can expect

For a deck that needs a permit, a typical sequence is:

1. Plan review. The office reviews a site plan and construction drawings. Some offices accept a completed prescriptive deck worksheet in place of drawings.
2. Footing inspection. This happens after holes are dug and before concrete is poured, so the inspector can check depth and bearing.
3. Framing inspection. This happens before decking covers the structure, so the inspector can see the ledger attachment, flashing, joist hangers, beams, posts, and lateral connections.
4. Final inspection. Guards, stairs, handrails, and overall completion are checked.

Some jurisdictions combine steps, and electrical work for deck lighting or receptacles is often a separate permit. Ask the office how to schedule inspections and how much notice it needs.

What to prepare

• Site plan showing the house, the deck footprint, distances to each property line, and any easements.
• Framing plan with joist size, spacing, and span; beam size; post size and height; footing size and depth; and the ledger attachment method.
• Elevation or section showing deck height above grade, guard height, and the stair layout.
• Materials list, including lumber treatment and fastener and connector types.
• Contractor information if someone else is building it, or confirmation that you are permitted to pull an owner-builder permit.
• HOA approval letter if your community requires one. Some permit offices ask to see it.

How permit fees are calculated

We don’t publish a single “deck permit cost” because fees are set locally and change often. Most offices use one of three methods:

• Valuation-based. The application asks for the value of the work (IRC R105.3 requires the applicant to “state the valuation of the proposed work”). The fee is a percentage or a stepped table based on that value. Many jurisdictions check stated values against the International Code Council’s Building Valuation Data, which the ICC describes as “a resource that jurisdictions across the U.S. use as a benchmark to determine building permit fees.” For example, the City of San Diego’s Information Bulletin 101 (January 2024) lists a valuation of $45 per square foot for wood decks. That is a valuation used to compute the fee, not the fee itself.
• Per square foot. A fixed rate times the deck area.
• Flat fee. A single fee for a residential deck, sometimes with separate plan-review and reinspection charges.

To estimate your cost, open your county’s fee schedule from our directory and ask the office which method applies to decks.

Common mistakes

• Measuring height at the wrong spot. The 30-inch test applies “at any point,” so a deck that is 18 inches high at the house can be 36 inches high at the far corner.
• Assuming “freestanding” means exempt. A freestanding deck larger than 200 square feet, or one serving the required exit door, still needs a permit.
• Lagging into veneer or skipping flashing. These are among the most common reasons a framing inspection fails.
• Pouring footings before the inspection. Once concrete is in, the inspector cannot verify the depth.
• Forgetting zoning. A deck that passes structurally can still violate a setback.
• Relying on the model code alone. Local codes often change the exemption thresholds or still enforce an older edition. Always read your jurisdiction’s version.