South Carolina ADU Laws

No statewide ADU law - entirely local control with unique incentive approach. HB 3469 (2025-2026) proposes property tax exemptions for ADUs rather than mandating local allowance - different strategy from other states. Incentive requires homeowner earning <250% AMI, renting to tenant earning <80% AMI, accepting Section 8, 10-year commitment. Charleston allows ADUs in any base zoning district with strict requirements: owner-occupancy, max 850 sqft, architectural consistency with primary dwelling, no short-term rentals, Declaration of Covenants required. Zoning districts that commonly allow ADUs: AGC, AGC-I, RUD, RUD-I, RSF-40, RSF-30, RMX-20, RMX-10, RMX-6, MU. South Carolina represents Southern conservative approach - financial incentives for affordable ADUs rather than regulatory mandates. Growing recognition of ADUs as housing solution but implementation through market mechanisms rather than government requirements.