Gaston County, NC Accessory Structures: ADU Rules (2026)

Unified Development Ordinance Sec. 17 allows a private residential quarters (PRQ) as an accessory use to any single-family detached dwelling, excluding manufactured homes. The PRQ may be attached to or physically separate from the main house. If detached, it must sit in the rear or side yard, observe a 15-foot rear and side setback, and cannot exceed the height of the principal dwelling; an attached unit instead follows the principal structure's own setbacks. The ground floor of the PRQ is capped at 50 percent of the principal dwelling's ground floor area or 1,000 square feet, whichever is smaller, and the county allows only one PRQ per lot.

Each PRQ must have at least one off-street parking space, and a manufactured home cannot be used as a PRQ. Sec. 6(A) separately confirms a PRQ does not count as a second principal residential building on the lot, and Sec. 9(A)(5) exempts private residential quarters from the county's numeric cap on accessory structures per lot. A narrower, second option exists only inside a Traditional Neighborhood Development: under Sec. 13(B)(3)(a), a detached single-family residence's garage in a TND may carry one accessory dwelling unit above it, and that garage-apartment unit is exempt from any additional off-street parking requirement, but that provision applies only within a platted TND, not countywide.

Outside a TND, the PRQ rules in Sec. 17 are the general accessory-dwelling standard for unincorporated Gaston County; Gastonia, Belmont, Mount Holly, Cherryville, Dallas, Stanley and Bessemer City set their own separate ADU rules inside their corporate limits.