ADUs are allowed in Unincorporated CharlestonTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Unincorporated Charleston, SC
Is your property eligible for an ADU?
# of Properties
32,103
Owner-occupied
78%
Zoning districts
77
Median Lot Size
0.60 acres
Avg Income
$104,015
Residential Types:
32,103 housing units
Single Family
66%
Apts (4+ units)
1%
Other
33%
Zoning Districts:
36,586 parcels · 77 districts
R-4
31%(11,457)
AGR
27%(10,012)
PD
8%(2,772)
RR
6%(2,016)
Other
28%(10,329)
ADU Rules
What can you build in Unincorporated Charleston, SC?
Unincorporated Charleston, SC follows state and local rules for Accessory Dwelling Units. Here is a concise overview of the local rules.
Eligibility
- –Internal / Attached ADU: By Right
- –Detached ADU: By Right
Interior / Attached ADU Size Limits
- –Maximum heated gross floor area for an internal or attached ADU: generally 800 sq ft in residential districts, 1,500 sq ft in agricultural districts; S-3 allows up to 1,200 sq ft; PF-O overlay up to 1,500 sq ft; FBZD T2 allows 1,500 sq ft and T3–T5 allow 800 sq ft.
Detached ADU Size Limits
- –Maximum heated floor area for detached ADUs: 800 sq ft in Residential districts; 1,500 sq ft in Agricultural districts; 1,200 sq ft in S-3; 1,500 sq ft in PF-O; within FBZD, 1,500 sq ft in T2 or 800 sq ft in T3–T5.
Owner Occupancy
- –No owner-occupancy requirement.
Parking
- –No ADU-specific minimum/maximum; ADU parking follows per-dwelling rates (FBZD: T2 2.0, T4 1.5, T5 1.0) with no separate ADU rate; off-site parking generally not allowed for residential (guest parking only) unless mixed-use.
Rental Restrictions
- –Short-term rentals allowed for ADUs with minimum 2-day bookings; annual cap 36 days (RHR) or 72 days (VHR). Accessory Structures shall not be used as STRPs.
What's allowed on your lot?
These are the municipality-wide rules. What's allowed on a specific property also depends on state laws, setbacks, floor area ratio, lot coverage, environmental constraints, topography, and other property-specific factors. Search your address on FutureLot to see what's allowed on your property.
Check my propertyHow can we help you?
Get matched with trusted local builders
Understand what's allowed on your property
Learn the key rules and size limits for ADUs
Is your property eligible for an ADU?
ADU rules in other South Carolina municipalities
Rules change at the town line. Check the municipality your property is actually in.
Charleston County
Browse addresses by ZIP in Unincorporated Charleston
294558,827 addresses294143,616 addresses294123,202 addresses294072,428 addresses294382,277 addresses294871,887 addresses294581,755 addresses294661,557 addresses294491,207 addresses294561,191 addresses29426988 addresses29429985 addresses29470683 addresses29485625 addresses29464588 addresses29406417 addresses29451316 addresses29420254 addresses29405183 addresses29418172 addresses