Do I Need a Permit to Build a Shed?

Nothing in this guide is legal advice. Permit rules are set locally, change on multi-year code cycles, and depend on the specifics of your project and address. This guide explains how the decision generally works and where the primary sources live — always confirm with your own Authority Having Jurisdiction (AHJ) before you build.

The 90-second version

• Most U.S. jurisdictions exempt small accessory structures from a building permit, based on a size threshold. The International Residential Code sets a common baseline of 200 sq ft for one-story detached accessory structures (IRC R105.2), but states and local jurisdictions amend this — some tighter, some looser.
• The threshold is set locally, not nationally. A shed exempt in one county can require a permit one town over. There is no single number that applies everywhere.
• Size isn't the only trigger. Wall height limits, electrical or plumbing work, proximity to property lines (setbacks), and whether the structure sits on a permanent foundation can all require a permit even under the size exemption.
• HOA rules are separate from permits and just as binding. A permit-exempt shed can still violate a homeowners' association's architectural rules. Check both.
• A plan set can help even when no permit is required — it documents what you built, which matters for resale, insurance, and any future addition.
• The only authoritative answer is your local building department. This guide tells you what to ask; it doesn't replace the answer.

Does the shed's size decide whether I need a permit?

Size is the most common trigger, but it's a local number, not a universal one. The International Residential Code — the model code most U.S. states adopt with local amendments — has historically exempted one-story detached accessory structures up to 200 square feet from requiring a building permit (IRC Section R105.2, "Work exempt from permit"). Many states and counties adopt that number directly. Others set it differently: California's state-adopted California Residential Code uses a 120 sq ft baseline, and some counties tighten further from there. The only way to know your actual number is to check your jurisdiction's current adopted code — not this guide, and not a generic "shed permit size" search result, since both can be out of date the moment a jurisdiction updates its amendments.

What is the IRC baseline, and does my state use it?

The IRC is a model code — a template that states adopt and then amend. Adoption isn't automatic or uniform: a state can adopt an IRC edition years after its release, and can change specific sections (like the accessory-structure exemption) on the way in. That means "the IRC says 200 sq ft" is a useful starting point, not a guarantee for your address. The ICC's code adoption tracker shows which edition each state currently has adopted, which is a better starting point than assuming the national baseline applies where you live.

Which factors trigger a permit even under the size threshold?

Size is one axis; several others operate independently of it, and any one of them can require a permit on a structure that's otherwise under the square-footage exemption:

• Wall height. Some jurisdictions cap exempt structures by height rather than (or in addition to) footprint — a tall shed can trigger a permit even at a small footprint.
• Electrical, plumbing, or mechanical work. Running power or water to a shed almost always needs its own separate permit, regardless of the structure's size exemption.
• Setbacks. Even a fully exempt structure typically still has to sit a minimum distance from property lines, easements, and sometimes septic fields — a zoning rule, not a building-permit rule, but enforced separately and just as binding.
• Foundation type. A shed on skids or blocks is treated differently in some jurisdictions than one on a permanent poured foundation.
• Flood zones and coastal wind-load requirements. Jurisdictions in FEMA flood zones or hurricane-prone coastal counties frequently apply engineering and elevation requirements regardless of size.

Each of these is set locally. The way to find out which apply to you is the same for all of them: ask your AHJ before you design around an assumption.

What about HOA rules — are those separate from permits?

Yes, and they're enforced independently. A homeowners' association's covenants can restrict shed size, placement, materials, and color regardless of what the local building code exempts — an HOA can require its own approval process for a structure the city doesn't require a permit for at all. Violating HOA rules doesn't carry criminal or code-enforcement penalties the way an unpermitted structure sometimes can, but it can mean fines, a forced teardown, or complications at resale. If you're in an HOA, check its architectural review process as its own separate step, not as part of the permit question.

Do plans and drawings help even if I don't need a permit?

Yes, for reasons unrelated to the permit question itself. A documented plan set — framing drawings, a materials list, dimensions — gives you a record of what you actually built, which matters at resale (a buyer's inspector or appraiser may ask), for homeowners' insurance (some policies want to know what's on the property and its value), and for any future addition or modification, since you'll want to know your existing framing before you build against it. Design documents like the ones ShedBuilder.ai generates support a permit submission where one's required — cover sheet, floor plan, elevations, framing plans, and (for supported jurisdictions) county-specific forms — but they are design aids, not PE-stamped engineering documents, and they don't replace your own confirmation with your AHJ. See pricing for what's included at each plan level.

What if I build without checking first?

The risk isn't uniform, which is exactly why it's worth checking rather than guessing. Unpermitted structures that turn out to require a permit can face a stop-work order, a retroactive permit and inspection process (sometimes at a penalty fee), or in rarer cases removal — and can complicate a home sale, since many jurisdictions require permit disclosure or an as-built survey at closing. None of that is likely for a genuinely exempt small shed, but "genuinely exempt" is exactly the fact worth confirming before you build, not after.

How often do permit thresholds change?

Often enough that "I checked a few years ago" isn't a safe basis for a build today. Building codes are typically revised on a multi-year cycle (the IRC itself is updated roughly every three years), and individual states and counties can amend their local thresholds independently of that cycle, in either direction — a county can tighten its accessory-structure exemption after a code review, or loosen it, as happened when Laramie County, Wyoming moved its threshold from 200 to 400 square feet in late 2025. That's exactly why this guide cites primary sources rather than a fixed number: the sources (the ICC's code text and your AHJ) stay current; a number frozen in an article doesn't. It's also why this specific guide carries a visible "last reviewed" date and a scheduled re-verification — check the footer for both.

How do I find my AHJ and ask the right question?

Your AHJ is usually your city or county building/permitting department — a web search for "[your city or county] building permit shed" or "[your county] planning and zoning" will typically get you to the right office, and most publish their accessory-structure thresholds online. When you call or email, ask the specific version of the question: "What's the maximum square footage for an accessory structure without a building permit at my address, and are there separate height, setback, or foundation rules that apply regardless of size?" That question gets you a usable answer; "do I need a permit for a shed" often doesn't, because the honest answer depends on details only your local office can confirm.

Where to go next

Once you know your local threshold, browse shed plans to find a starting layout, or see what's actually in a shed plan set if you're deciding whether you need one.

Last reviewed August 19, 2026. Found something that's changed or looks wrong? Email support@shedbuilder.ai and we'll take a look.