ADU rules in Goose Creek

Goose Creek's Unified Development Ordinance lists 'Dwelling, Accessory' as a C use (allowed subject to conditions) in the Residential Single-Family (RSF) and Residential Mixed (RM) districts, and the code defines C uses as 'permitted by right' once the use standards are met. A detached ADU (for example an apartment above a detached garage or a guesthouse) must sit at least 10 feet from the house, be in the same base zoning district as the house, and meet the principal side and rear setbacks; it may not be in the front or corner yard. One ADU per lot, and only on a lot with a single-family detached house. The Conservation, Village Node and nonresidential districts do not list the use.

The same 'Dwelling, Accessory' use covers a unit within or attached to the house (for example a downstairs or upstairs apartment), allowed by right with standards in RSF and RM. An attached unit must be attached to the principal structure and have an operative interconnecting door with it. The unit must keep the same street address, mailbox and water, sewer, gas and electric utilities as the house, and only one kitchen is allowed per ADU.

The floor area of an ADU is capped at 1,200 square feet or half the floor area of the house, whichever is smaller, so a 1,800 square foot house allows at most 900 square feet. ADUs do not count toward the district density limits or toward the size limits for accessory structures, but they must keep the general design, style, appearance, height and character of the house.

The 2026 UDO has no owner-occupancy rule for ADUs. The February 2024 zoning chapter (as restated by Ord. 2025-007) required that 'Either the principal dwelling unit or the accessory dwelling unit must be the permanent, full-time residence of the owner of the lot'; the June 2026 rewrite deleted that standard (the standards list now jumps from 5 to 7 where it was removed). The ADU still may not be subdivided or separately owned.

The UDO parking table lists 'Dwelling, Accessory' as N/A, so no additional off-street space is required beyond the house's 2 spaces per dwelling unit. The ADU must use the same driveway as the house unless it is reached from a right-of-way the house does not use (a rear alley, or a second street on a corner or through lot).

A C use in Goose Creek is 'permitted by right' subject to its listed standards, unlike S uses, which need a Board of Zoning Appeals special exception. An ADU therefore needs a zoning permit (with a site development plan showing compliance) and a building permit, then a certificate of occupancy, all staff-level.

The UDO does not restrict renting an ADU long term, but the unit may not be 'subdivided or otherwise segregated in ownership' from the house. Code of Ordinances Chapter 113 (Ord. 2023-024) defines a short-term rental unit as 'a dwelling unit, principal or accessory,' rented in its entirety for less than 30 consecutive days, allows them in residential districts subject to HOA and covenant verification, and requires an annual city STR permit, a business license, adjacent-owner notice and payment of fees and taxes. The city's STR guidance page is stricter than the codified text: it reads 'principal or primary' and says the rented unit 'cannot be an accessory structure,' with one STR per lot and one parking space per bedroom, so confirm with the Business License office before planning to rent an ADU nightly.