Accessory Structures in Columbia, SC (2026)
8 verified accessory structures rules for Columbia, South Carolina, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Columbia's UDO addresses accessory dwelling units. ADUs may be permitted in certain residential zones subject to size and design standards.
Columbia SC ADU Rules
Some RestrictionsADU Permits
Columbia permits accessory dwelling units (ADUs) under the Unified Development Ordinance (UDO), Chapter 17 Sec. 17-4.3(c) of the Columbia Code of Ordinances. An ADU requires a zoning permit and a building permit, with construction subject to the 2021 International Residential Code as adopted by the South Carolina Building Codes Council. ADUs may be attached, internal (basement or upstairs), or detached, and floor area is capped at the lesser of 1,000 square feet or 50% of the principal dwelling's floor area.
Columbia ADU Permit Process
Some RestrictionsADU Impact Fees
Columbia does not impose general municipal impact fees on residential ADUs. New connections to Columbia Water trigger water and sewer tap fees and capacity charges. Any local impact fee in South Carolina must comply with the strict procedural rules of the SC Development Impact Fee Act (SC Code §6-1-910 to §6-1-2010), which requires a capital improvements plan, public hearings, and a rational nexus between the fee and the service. Standard zoning and building permit fees from Columbia's fee schedule apply.
Columbia ADU Impact Fees
Some RestrictionsADU Owner Occupancy
Columbia's Unified Development Ordinance Sec. 17-4.3(c) requires that either the principal dwelling or the accessory dwelling unit be the permanent, full-time residence of the owner of the lot. This owner-occupancy condition applies to every ADU citywide, regardless of whether it is rented long-term or owner-used. Only one ADU is allowed per lot, and the ADU and principal dwelling remain a single legal parcel that cannot be sold separately.
Columbia ADU Owner Occupancy
Heavy RestrictionsADU Rental Restrictions
Columbia allows long-term rental of an ADU subject to the UDO Sec. 17-4.3(c) owner-occupancy condition: either the principal dwelling or the ADU must be the owner's permanent residence. Short-term rental (30 days or less) of an ADU is regulated by Columbia Ord. 2023-037, which requires a Short-Term Rental Permit, a city Business License, and a local representative within 45 miles of city limits. Long-term tenancy is otherwise governed by the SC Residential Landlord and Tenant Act, SC Code §27-40, and University of South Carolina student rentals are common in nearby neighborhoods.
Columbia ADU Rental Restrictions
Some RestrictionsShed Rules
Columbia allows sheds subject to size and setback requirements. Small sheds may not require building permits.
Columbia SC Shed Rules
Some RestrictionsGarage Conversions
Columbia requires building permits for garage conversions. The space must meet building code standards for habitable rooms.
Columbia SC Garage Conversion Rules
Some RestrictionsCarport Rules
Columbia regulates carports as accessory structures under Sec. 17-4.3 of the Unified Development Ordinance. Detached carports must meet accessory-structure setbacks and zoning standards, with a building permit generally required if the structure exceeds 200 sq ft.