Accessory Structures in Beaufort County, SC (2026)

ADU Rules

Unincorporated Beaufort County (mainland areas outside Hilton Head Island, Bluffton, the City of Beaufort, and Port Royal) regulates accessory dwelling units through the form-based Beaufort County Community Development Code (CDC). The CDC treats ADUs as a 'Carriage House' building type under Article 5, Division 5.1 (Building Type Standards), allowed in most form-based transect zones (T3, T4, T5) subject to size, design and parking standards. Daufuskie Island has its own appendix (Appendix B) capping auxiliary dwelling units at 800 square feet. A zoning permit is required before placement, plus a building permit for any structure 200 square feet or larger, and an accessory dwelling cannot be placed on a lot without a principal structure.