Charleston, SC Accessory Structures: Tiny Homes (2026)

Sec. 54-214 of the Zoning Ordinance lets the Zoning Administrator approve one accessory dwelling unit (ADU) as an accessory use to a principal single-family home in any base zoning district, effectively Charleston's version of a permitted backyard tiny home. Only one ADU is allowed per lot, and the total dwelling count on the lot, including the ADU, cannot exceed two units. The ADU can include no more than 850 square feet of conditioned floor area; if it sits in an accessory building that uses the setback exceptions of Sec.

f, its footprint shrinks to a 600-square-foot cap. At least one off-street parking space must be provided for the ADU, which can be arranged in tandem with parking for the existing house. Before permitting, the applicant submits a scaled site plan and a draft Declaration of Covenants and Restrictions (DCR) to the Department of Planning and Preservation and the Office of Corporation Counsel; the DCR must be recorded before a certificate of occupancy issues. The DCR requires that either the principal home or the ADU be owner-occupied, bars subleasing the ADU separately unless the owner lives in neither unit, and caps ADU occupancy at two adults.

Neither the principal home nor the ADU can be used as a short-term rental, and the property cannot be converted into a horizontal property regime. If the ADU receives a City financial subsidy and is rented for income, it must serve households at or below 80 percent of area median income for at least 30 years, verified annually by the Department of Housing and Community Development. Violating the covenant lets the City revoke the certificate of occupancy.