What Can You Build Without a Permit in Delaware? (2026)
The 30-second answer for Delaware
In Delaware, the projects you can usually build without a building permit are a small detached shed, a short freestanding deck, a fence under the height cap, a low retaining wall, and cosmetic interior work. The exact limits Delaware enforces are in the table below — and your city can be stricter than the state. The catch every homeowner needs to hear: even when no permit is required, the building code, zoning setbacks, and any HOA rules still apply. Permit-exempt means the paperwork is waived, not the rules.
How Delaware sets the rules
Delaware has NO statewide residential building code. The three counties (New Castle, Kent, Sussex) plus each incorporated city and town adopt and enforce their own codes and their own permit-exemption lists. New Castle County and Sussex County enforce the 2021 IRC (effective 1/1/2024 and 1/1/2023 respectively); Kent County enforces the 2018 IRC. There is no single answer statewide — the county (or town) your lot sits in controls.
Permit-exempt limits in Delaware
These are the thresholds we verified for Delaware. Treat each one as the most you can usually do without pulling a permit — a stricter city amendment always wins.
| Project | Delaware permit-exempt limit |
|---|---|
| Detached shed / accessory building | Set by county, not the state. New Castle County exempts one-story detached accessory structures (tool/storage sheds, playhouses, pergolas, free-standing gazebos) up to 200 SF with an eave height of 10 ft or less and overall height of 20 ft or less; garages/vehicle-capable structures are NOT exempt. Kent County reportedly uses a higher cutoff (~300 SF — confirm with Kent County). Sussex County requires a permit for an accessory building of ANY size. |
| Deck | New Castle County exempts decks not exceeding 200 SF that are not more than 30 in above grade AND are not adjacent to, or attached to, a one- or two-family dwelling — stricter than the plain IRC because a freestanding deck merely next to the house does not qualify. Sussex County requires a permit for a deck of any size; confirm Kent County and towns locally. |
| Fence | In New Castle County, fences of ANY height are exempt from a building permit — only swimming-pool barrier fences require one. This is more lenient than the IRC's 7-ft trigger on the permit side, but it is NOT permission to build any height: zoning still caps fence height and setbacks. Sussex County and incorporated towns set their own fence rules. |
| Retaining wall | New Castle County exempts retaining walls not over 4 ft in EXPOSED height, unless the wall supports a surcharge or impounds Class I, II, or III-A liquids. Two adjacent walls close together are treated as a single wall. Note the 4 ft is measured as exposed height, not the IRC's bottom-of-footing to top. Sussex County: confirm locally. |
| Patio (on grade) | New Castle County exempts non-structural concrete slabs, patios, and decorative hardscaping not more than 30 in above grade, and separately exempts sidewalks and driveways. A driveway apron in the public right-of-way may still need a DelDOT entrance permit. Sussex County requires a building permit for essentially all construction; confirm locally. |
Baseline: 2021 International Residential Code, Section R105.2. See the national project-by-project guide for how each threshold works.
Can you do the work yourself in Delaware?
Yes. Delaware lets a property owner pull the permit and do the work on their own home. In Sussex County this is set by statute — 9 Del. C. 6302(b) authorizes permits for any owner of property desiring to do their own work about their own building. New Castle County and municipalities likewise issue homeowner permits. Electrical is licensed and inspected at the STATE level, but owner-occupants of a single-family home can obtain a state Homeowner Electrical Permit.
What's different about Delaware
There is no statewide code — it is a three-county patchwork
Delaware has no statewide building code, so permit exemptions are set county-by-county (and town-by-town). New Castle County exempts detached sheds up to 200 SF, Kent County uses a higher cutoff (~300 SF, confirm locally), and Sussex County requires a permit for an accessory building of any size. The same shed can be permit-exempt on one side of a county line and require a permit on the other.
Sussex County has essentially no small-structure exemption
Sussex County states that all construction — new, remodeling or additions — requires a Sussex County building permit. There is no 200-SF free pass like New Castle County: even a small storage shed needs a county permit, and coastal/flood-zone lots add elevation requirements.
Delaware handles electrical at the state level, not the county
New Castle County does not permit or inspect electrical work; licensed electricians use a state-approved inspection agency, and a homeowner can get a Homeowner Electrical Permit from the state Board of Electrical Examiners. This is unusual — in most states electrical is permitted by the same local building department.
"Permit-exempt" does not mean rule-free
I spent 25 years as a firefighter before I built PermitDeck, so let me be blunt about the part that gets people hurt. "No permit" never means "no rules." When a project is exempt in Delaware, three things are still true — and now you are the one responsible for them, because no inspector is coming to check:
- Building code still applies. An exempt deck in Delaware still has to meet the structural rules of IRC R507 — real footings, a proper ledger, and guards. A shed still has to carry your local snow and wind load. The code does not care whether a permit was pulled.
- Zoning and setbacks still apply. Exempt does not mean you can put it anywhere. Setbacks from property lines, easements, lot-coverage caps, and corner-lot sight lines all still bind you — and a neighbor complaint can force you to move it.
- HOA rules are separate. Your HOA architectural review is a private contract, not a government permit. You can be fully permit-exempt with your city and still be forced by your HOA to tear something out.
The big Delaware cities
Permits are pulled locally, so your city's building department has the final word. Here are the two largest, with a link straight to their office.
New Castle County
Department of Land Use. Enforces the 2021 IRC. Its Work Exempt from Permit list (Rev. 1/1/2026) exempts detached sheds up to 200 SF, decks up to 200 SF and 30 in high (not attached/adjacent), fences of any height except pool barriers, and retaining walls up to 4 ft exposed height.
New Castle County building departmentWilmington
Wilmington issues its own permits through the Department of Licenses & Inspections; it does not simply defer to New Castle County. Even a permit-exempt small shed triggers a city zoning/setback review, so call before building.
Wilmington building departmentTurns out you do need a permit? We'll match you with pros who pull it
If your project crosses one of these Delawarethresholds, the cleanest path is to hire a licensed pro who pulls the permit in their own name and stands behind the inspection. Tell us the project once and we'll send it to up to three verified local pros. It's free, it's capped at three, and we never sell your information — the opposite of the lead-farm sites.
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What happens if you needed a permit and skipped it
Guessing wrong on the exemption is not a small risk. The common outcomes are a stop-work order, a fine (often double the normal permit fee), and being ordered to open finished work back up for inspection or tear it out. The expensive part usually lands later: unpermitted work routinely kills a home saleat the buyer's inspection, and an insurance claim can be denied if the damage traces back to unpermitted construction. Most jurisdictions do allow a retroactive (after-the-fact) permit — it costs more, but it clears the record.
Full detail: what happens if you build without a permit and how to get a building permit.
Delaware permit-exemption FAQs
Do I need a building permit for a shed in Delaware?
It depends entirely on the county, because Delaware has no statewide rule. New Castle County exempts a detached shed up to 200 square feet; Kent County uses a higher cutoff (confirm with Kent County); but Sussex County requires a permit for an accessory building of any size, even a small storage shed. Always check the county or town where your lot sits before building.
Does Delaware have a statewide building code?
No. Delaware has no statewide residential building code. New Castle, Kent, and Sussex counties, plus every incorporated city and town, each adopt and enforce their own codes and exemption lists. New Castle and Sussex counties use the 2021 IRC; Kent County uses the 2018 IRC. The same project can be permit-exempt in one jurisdiction and require a permit in the next one over.
Do I need a permit to build a fence in Delaware?
In New Castle County, a fence of any height is exempt from a building permit — only swimming-pool barrier fences need one. But that is not a license to build any height: zoning still caps fence height and setbacks. Sussex County and incorporated towns set their own fence rules, so verify locally before installing.
Can a homeowner pull their own permit in Delaware?
Yes. Delaware law lets a property owner obtain a permit and do the work on their own home — in Sussex County this is written into statute (9 Del. C. 6302(b)), and New Castle County and towns issue homeowner permits too. Electrical work is licensed and inspected at the state level, but an owner-occupant can get a state Homeowner Electrical Permit.
Sources we verified against
- New Castle County — Work Exempt from Permit (Dept. of Land Use, Rev. 1/1/2026)
- Sussex County — Building Permits and Licenses (all construction requires a permit)
- ICC-NTA — Sussex County adopts 2021 IBC/IRC, effective 1/1/2023
- Delaware Code Title 9, Chapter 63 (owner-builder 6302(b))
- City of Wilmington — Department of Licenses & Inspections
Every threshold on this page is anchored to Delaware's building code or the sources listed above. Where a number varies by city and we could not verify it, we say "verify locally" rather than guess — a permit page you cannot trust is worse than no page at all.
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