What you can build without a permit in Delaware

By Mario Bailey Last checked 3 Oct 2026 · 10 official sources

Quick answer

Across the 2 Delaware jurisdictions we have verified, 0 of 26 project rules need no permit at all, 12 turn on a size or scope condition the jurisdiction publishes, and 14 require a permit regardless. Bathroom remodel work is where the answer most often comes with a published condition rather than a flat yes: 2 of the 2 jurisdictions that answer publish one.

How to read this page

"No permit" means the jurisdiction publishes that the work needs no building permit. "Depends" means it publishes a size, height, depth, cost or scope condition that decides the answer, quoted in its own words in the last column; the number beside it is the figure that condition turns on, and which side of the number is exempt is stated by the condition, not by us. Exempt from a building permit is not exempt from zoning, setbacks, height limits, flood rules, an HOA, or a separate electrical, plumbing or mechanical permit, and several of the conditions below say exactly that.

Bathroom Remodel

All 2 make the bathroom remodel answer turn on a size or scope condition the jurisdiction publishes.

Jurisdiction	Permit	Published figure	What the rule says
New Castle County	Depends		Finish work (tiling, cabinets, counter tops) and in-place fixture reinstallation are exempt; new or moved plumbing, walls or circuits are not.
Sussex County	Depends		Cosmetic finishes and like-for-like fixture swaps versus renovation, relocated or added plumbing, or new electrical work.

Roof Replacement

All 2 make the roof replacement answer turn on a size or scope condition the jurisdiction publishes.

Jurisdiction	Permit	Published figure	What the rule says
New Castle County	Depends	25 percent	Share of the roof sheathing repaired or replaced during a re-roof.
Sussex County	Depends		Permit applies when the job includes structural sheathing or a change in roofing material.

Deck

1 of 2 makes the deck answer turn on a size or scope condition the jurisdiction publishes. Sussex County requires a permit for deck work regardless of size.

Jurisdiction	Permit	Published figure	What the rule says
New Castle County	Depends	200 sq ft	Floor area of a free-standing deck no more than 30 inches above grade and not adjacent to or attached to the dwelling.
Sussex County	Permit required		Sussex County lists wood decks, porches and sunrooms among additions that require a county permit, with no size or height exemption.

Fence

1 of 2 makes the fence answer turn on a size or scope condition the jurisdiction publishes. Sussex County requires a permit for fence work regardless of size.

Jurisdiction	Permit	Published figure	What the rule says
New Castle County	Depends		Only fences that serve as swimming pool barriers need a permit.
Sussex County	Permit required		Authority: Sussex County issues the building permit (Building Permit Office, Georgetown) for all construction in the county, including inside municipalities, but plan review and inspection by the county Building Code Office covers only unincorporated Sussex County plus 14 towns that contract for it (Bethel, Blades, Bridgeville, Dagsboro, Dewey Beach, Ellendale, Fenwick Island, Frankford, Georgetown, Greenwood, Henlopen Acres, Ocean View, Slaughter Beach, South Bethany).

HVAC

1 of 2 makes the HVAC answer turn on a size or scope condition the jurisdiction publishes. New Castle County requires a permit for HVAC work regardless of size.

Jurisdiction	Permit	Published figure	What the rule says
Sussex County	Depends		Replacement of existing equipment versus a new installation or additional unit.
New Castle County	Permit required		A County HVACR/gas (mechanical) permit is required to install, alter, repair, convert or replace any gas or mechanical system in unincorporated New Castle County.

Patio

1 of 2 makes the patio answer turn on a size or scope condition the jurisdiction publishes. Sussex County requires a permit for patio work regardless of size.

Jurisdiction	Permit	Published figure	What the rule says
New Castle County	Depends	30 inches	Height of a non-structural slab, patio or decorative hardscaping at any point.
Sussex County	Permit required		Sussex County's published list of projects requiring a county permit includes concrete, brick and paver patios, with no size or covered/uncovered distinction.

Pool

1 of 2 makes the pool answer turn on a size or scope condition the jurisdiction publishes. Sussex County requires a permit for pool work regardless of size.

Jurisdiction	Permit	Published figure	What the rule says
New Castle County	Depends	24 inches	Pool, spa or hot tub wall height; any pool designed to connect to a circulation system needs a permit regardless of height.
Sussex County	Permit required		Sussex County requires a county permit for in-ground and above-ground pools, with no depth or size exemption published.

Shed

1 of 2 makes the shed answer turn on a size or scope condition the jurisdiction publishes. Sussex County requires a permit for shed work regardless of size.

Jurisdiction	Permit	Published figure	What the rule says
New Castle County	Depends	200 sq ft	Floor area of a one-story detached accessory structure with an eave height of 10 feet or less and overall height of 20 feet or less; garages never qualify.
Sussex County	Permit required		Sussex County requires a county permit for all sheds, pre-built and site built, with no size exemption.

Solar

1 of 2 makes the solar answer turn on a size or scope condition the jurisdiction publishes. Sussex County requires a permit for solar work regardless of size.

Jurisdiction	Permit	Published figure	What the rule says
New Castle County	Depends		Rooftop panels on a one- or two-family dwelling are exempt from the County building permit; electrical work still goes through the State.
Sussex County	Permit required		Sussex County requires a county permit for solar panel installations, both ground mounted and structure mounted.

Water Heater

1 of 2 makes the water heater answer turn on a size or scope condition the jurisdiction publishes. New Castle County requires a permit for water heater work regardless of size.

Jurisdiction	Permit	Published figure	What the rule says
Sussex County	Depends		Replacement of an existing water heater versus a new or relocated one.
New Castle County	Permit required		Replacing or installing a water heater requires a County permit in unincorporated New Castle County: the plumbing exemption for in-place fixture work expressly does not apply to water heaters.

If the work is already built

Delaware sets no single statewide fine for building without a permit. Instead, Title 9 of the Delaware Code gives each of the three counties its own building permit chapter, and the penalty depends on where the work sits.

Delaware penalties, the after-the-fact path, and what the statute actually says

The 26 answered rules come from 10 official sources, each linked from the permit page behind every jurisdiction name. See the full picture for the state on the Delaware permit requirements page, or the national view of which projects need a permit at all on Do you need a building permit?

This page compiles what each Delaware jurisdiction publishes, with a last checked date. It is not legal advice, and a project that is exempt from a building permit can still need zoning approval or a trade permit. Confirm with the office linked from the jurisdiction's page before you build.