In most cases you do not need a permit for a floating deck, provided it stays no larger than 200 square feet, no higher than 30 inches above the ground, is not attached to the house, and does not sit in front of a door your building code treats as a required exit. Miss any one of those four conditions and the exemption falls away for the entire project. And even when the building department gives you a pass, zoning setbacks, utility line laws, homeowners association rules, and electrical code can still apply.
The Four Conditions for a Permit Exemption
Section R105.2 of the International Residential Code, which most local building departments use as the backbone of their own codes, exempts a deck from permit requirements when all four of these are true at once:
- The deck is no more than 200 square feet in area.
- The walking surface is no more than 30 inches above the ground at any point.
- It is not attached to the house.
- It does not serve a door the code designates as a required means of egress.
A floating deck sits on concrete pier blocks or helical piers rather than bolting to the house with a ledger board, so the attachment condition is met by design. That leaves area, height, and the exit-door question as the three things you actually need to verify.1International Code Council. Deck Construction Based on the 2021 IRC – Section R105.2
The exit-door condition catches more homeowners than you might expect. If the deck sits outside a door your code treats as a required secondary exit — often a back or side door — the exemption does not apply no matter how small or low the deck is. A modest platform outside a kitchen slider can trigger a permit for that reason alone.
Watch the 30-Inch Line Carefully
The 30-inch height limit does double duty. It decides whether you need a permit, and it decides whether you need a guardrail. Any walking surface more than 30 inches above the ground at any point requires a guard, with a minimum height of 36 inches measured from the deck surface to the top of the rail.2UpCodes. Section R321 Guards and Window Fall Protection
The code measures from the highest point of the deck surface to the ground directly below. On sloped or uneven terrain, one corner can push above 30 inches even when the rest of the deck sits comfortably below it. Measure at the low side of the yard before you assume you’re clear.
What a Permit Exemption Does Not Excuse
Being exempt from a building permit is narrower than it sounds. Several other rules apply to floating decks regardless of size.
Zoning Setbacks
Setback requirements — the minimum distance any structure must sit from your property lines — apply even when the deck falls under the 200-square-foot exemption. Setback distances vary by jurisdiction and often by zoning district within a jurisdiction, so there is no single national number. Zoning violations are enforced separately from building code violations, and the local government can order a deck moved or removed regardless of how well it was built. Check your property survey before you break ground; if you don’t have one, your assessor’s office or local GIS mapping tool usually shows approximate boundaries, though only a professional survey is definitive.
Calling 811 Before You Dig
Even a ground-level floating deck involves leveling the site or setting piers. Federal law requires anyone planning to dig to first contact the national one-call notification system by dialing 811. The system routes your request to local utilities, who mark underground gas, electric, water, and communication lines in your work area at no cost.3Office of the Law Revision Counsel. 49 USC 60114 – One-Call Notification Systems
Every state has adopted a one-call system, and most require the call at least two to three business days before you dig. Penalties for skipping the call range from fines to full liability for repairing a damaged line. The U.S. Department of Transportation reports that calling 811 first results in a 99 percent chance of avoiding a utility strike.
Electrical Work
If you plan to wire the deck for lighting, outlets, or a fan, the electrical work almost always requires its own permit, even when the deck structure does not. The National Electrical Code requires GFCI protection on all outdoor receptacles and weather-rated covers on any outlet or junction box exposed to the elements. A deck accessible from inside the home through a door generally needs at least one receptacle installed no more than about six and a half feet above the deck surface. Wet-location fixtures are required in exposed areas; damp-location fixtures are acceptable under a roof overhang. Running new wiring to a freestanding structure typically calls for a licensed electrician and a final inspection.
HOA Architectural Review
If you live under a homeowners association, the CC&Rs likely require approval from an architectural review committee before you build anything visible from outside the home. This runs on a separate track from the building permit process. You can be fully exempt from a permit and still face fines or a removal order for skipping HOA review. Expect to submit a written application with design plans, dimensions, placement, materials, and in some cases written acknowledgment from adjacent neighbors. HOAs often impose limits on materials, colors, and dimensions that go beyond the building code.
Confirm the Rule for Your Address
The IRC is a model code, not a federal law. Each city, county, or township adopts and modifies it, so local rules can be stricter or more lenient than the baseline. Some communities set the permit-exempt threshold at 100 square feet instead of 200. Others require a permit for any structure at all.
Search your municipality’s website for “deck permit,” “building permit exemptions,” or “accessory structures.” Many building departments publish a decision flowchart or checklist for decks. If the site isn’t clear, call the building or planning department with your property address ready. A five-minute call up front is cheaper than a code enforcement visit later.
If Your Deck Does Need a Permit
When a floating deck exceeds 200 square feet, sits higher than 30 inches, or your jurisdiction simply doesn’t follow the standard IRC exemption, the process is straightforward but takes preparation.
Documents
You’ll need a site plan: a scaled drawing showing property lines, the house footprint, and the proposed deck location with measurements to each property line. This is what the department uses to confirm setback compliance. You’ll also need construction drawings with dimensions, joist and beam sizes, spacing, footing type, and materials. For a floating deck, footings are typically precast concrete pier blocks or helical piers rather than poured concrete, and your plans should say which. The application asks for an estimated project cost covering materials and labor, which determines the permit fee.
Fees, Review, and Inspections
Residential deck permit fees generally run from around $75 to several hundred dollars, depending on project size and the local fee schedule. Many jurisdictions accept online applications with electronic plan uploads and payment. A plans examiner reviews the application; the review can take from a few days to several weeks. Missing or non-compliant items come back as a correction notice. Once approved, the permit must be posted visibly at the job site. The department will schedule at least one inspection during construction and a final inspection before signing off.
What Happens If You Skip a Required Permit
Building without a permit when one is required creates problems that compound, and they are always more expensive than the permit would have been.
Stop-Work Orders and Fines
When a building inspector or code enforcement officer discovers unpermitted work — through a neighbor complaint, a routine survey, or aerial and satellite imagery — the first step is usually a stop-work order. Work cannot resume until you apply for and receive the proper permit, and most jurisdictions charge penalty fees on top of the standard permit cost. Some double or triple the original fee; others impose daily fines that accumulate until the violation is resolved. Where the structure violates setbacks or poses a safety hazard, you can be ordered to tear it down at your own expense.
Problems When You Sell
Unpermitted structures create lasting complications. You are generally required to disclose known unpermitted work to potential buyers, which can lower the sale price and narrow the buyer pool. Lenders may refuse to approve a mortgage on a property with known code violations. Sellers sometimes end up demolishing or retrofitting the unpermitted structure just to close the deal.
Insurance
Homeowners insurance adds another layer of exposure. If damage tied to unpermitted work occurs — a collapse, a fire traced to improperly run wiring, a guest injury on an uninspected structure — an insurer may deny the claim on the grounds that the work was never inspected or brought up to code. Discovery of unpermitted construction during a claim investigation can also lead to policy cancellation or non-renewal.