Onslow County, NC Accessory Structures: Shed & Carport Rules (2026)

Table 8-3's Note 1 sets the core size cap: "The total square footage of enclosed accessory structures shall not exceed 50 percent of the total square footage of the principal structure and will not apply to pools and decks. This limitation does not apply in the RA (Rural Agriculture) Zoning District. If the accessory structure is to be over 50 percent, then it shall require a Special Use Permit." A homeowner with a 2,000-square-foot house can build up to 1,000 square feet of enclosed sheds and outbuildings by right; going bigger means a Special Use Permit hearing, unless the lot sits in RA where the cap does not apply at all.

Placement in the front yard is limited by Table 8-2: open structures like carports can go in front, but enclosed sheds cannot on lots under 2 acres. Lots of 2 acres or more, flag lots, and RA-zoned lots are eligible for front placement, while waterfront lots need a Special Use Permit for it. Note 3 to that table adds that no part of an enclosed accessory structure can sit forward of the principal structure except under those listed allowances.

Setbacks follow Table 8-3 by lot type and shed size. On an interior lot, a shed under 400 square feet needs only 5 feet from the side and rear property lines; at 400 square feet or larger, that jumps to 8 feet on both. Corner lots and double-frontage lots carry heavier rear setbacks of 10 to 15 feet. Manufactured homes can qualify as an accessory storage structure in RA only with an engineered setup plan, and RVs, campers, trailers, boats, and buses can never be used or counted as accessory structures under the notes to Table 8-3. Sheds also cannot sit inside any recorded easement or right-of-way.