Can I Build ADU in Charleston, SC? (2026)

What is the Board of Architectural Review (BAR) and do I need its approval?

The Board of Architectural Review (BAR) is Charleston's historic preservation review body, established in 1931 — one of the oldest in the US. It reviews all exterior alterations, new construction, and demolitions in the Old and Historic Charleston District (the entire downtown peninsula). If your property is in the Historic District, you must obtain a Certificate of Appropriateness (COA) from the BAR before doing any exterior work, in addition to standard building permits. The BAR reviews materials, window styles, additions, colors, and landscape elements. The BAR meets monthly — submit your application at least two weeks in advance.

Can I convert a carriage house or dependency structure to an ADU in Charleston?

Yes — and it's actually encouraged. Converting a historic carriage house, kitchen house, or outbuilding (dependency structure) to an ADU is historically appropriate and consistent with Charleston's traditional residential pattern. These conversions are viewed favorably by the Board of Architectural Review when materials and design are contextually appropriate. You need a building permit from Charleston Building Inspections and a Certificate of Appropriateness from the BAR for Historic District properties. No replacement parking required when the original structure had no off-street parking.

What are the short-term rental restrictions in Charleston?

Charleston has a strict STR ordinance requiring a license ($200/year) from the Revenue Division. In most residential zones on the historic peninsula, only owner-occupied (primary residence) short-term rentals are allowed — the owner must live on-site. Non-owner-occupied Commercial STR licenses are restricted to specific commercial and mixed-use zones, and no new Commercial STR licenses have been issued in most historic residential areas since 2022. Properties must pass a life safety inspection. Occupancy limits apply (2 guests per bedroom, 4 maximum in most residential areas). Enforcement is active in Charleston.

How serious is flooding risk in Charleston?

Very serious. Charleston's historic peninsula sits at an average of 7 feet above sea level and faces rising sea levels, increasing King Tide flooding, and major hurricane storm surge risk. Hurricane Hugo (1989) flooded much of Charleston's peninsula. Today, even routine high tides flood parts of downtown during full moon events. Most peninsula properties are in FEMA Special Flood Hazard Areas requiring flood insurance with federally-backed mortgages. New construction requires elevated first floors above Base Flood Elevation. Check FEMA flood maps and consult with Charleston's floodplain management staff before any construction in low-lying areas.

Does South Carolina have a statewide ADU law?

No. South Carolina has no statewide ADU preemption law. Each municipality sets its own ADU rules under South Carolina Code Section 6-29-720. Charleston, Greenville, Columbia, and other SC cities have different ADU regulations. Unlike North Carolina (which passed HB 488 in 2023) or California, South Carolina cities retain full local control over ADU policy. Always check with the specific city's planning department.

What solar considerations apply to Charleston Historic District properties?

Solar installations in Charleston's Historic District require Board of Architectural Review (BAR) approval. BAR guidelines generally permit solar panels on rear-facing roof slopes not visible from public streets. Front-facing panels on contributing historic structures typically face strong scrutiny and may be denied. Consult BAR staff before purchasing equipment. Outside the Historic District, South Carolina's solar incentives are attractive: 1:1 retail net metering (Dominion Energy SC), Federal ITC (30%), and South Carolina's 25% state solar tax credit (max $3,500).