Accessory Dwelling Unit (ADU)

  1. General Information
  2. Requirements
  3. Application Materials

One Accessory Dwelling Unit (ADU) may be approved in any base zoning districts as an accessory use to a principal single-family dwelling unit if all  conditions listed in Sec. 54-214 of the City of Charleston Zoning Ordinance are met.

An ADU is defined as, "a dwelling unit providing complete, independent living facilities for no more than two (2) adults that is separate from, and subordinate to, the principal dwelling unit, and located in the same building as the principal dwelling unit or in an accessory building on the same lot. This definition includes garage apartments."

Conditions for approval include, but are not limited to, the following:

- Either the principal structure or the ADU must be owner-occupied.  If the ADU is to be rented for compensation, monetary or otherwise, the ADU must meet Affordable Housing income and rental thresholds as defined in Sec. 54-120 of the City of Charleston Zoning Ordinance (household income of no more than 80% of median area income). 

- Neither the principal dwelling unit nor ADU shall be utilized for Short Term Rental.

- The property shall not be converted into Horizontal Property Ownership Regime.

- Applicant shall provide a copy of a recorded covenant affidavit that certifies that no covenants exist that would prohibit the construction of an ADU.

- One parking space shall be provided in addition to parking required for existing uses on property.

- Each ADU is limited to 850 square feet of conditioned floor space.

- ADU occupancy is limited to no more than two (2) adults.

- A covenant shall be recorded that memorializes the ADU conditions.