Accessory Dwelling Units (ADU) are separate, self-contained dwellings that include living, sleeping, sanitary, and cooking facilities. An ADU can be located within the principal single-family residential building or in a detached, accessory building on the same lot where the principal single-family dwelling unit is located. Occupancy of an ADU is restricted to no more than two (2) adults and any number of children, with “adult” being any person eighteen years of age or older.
Requirements for City approval include, but are not limited to, the following:
ADUs may be approved in any base zoning district
The lot must not be encumbered by covenants that prohibit the construction or use of an ADU.
Not more than one ADU is permitted per lot and the total number of dwelling units on the lot, including the ADU, cannot exceed two units.
The ADU may be separately metered for electricity, gas, and water.
To be approved, the lot where the ADU will be located must provide one parking space, in addition to providing the required number of parking spaces for the existing single-family dwelling and any other uses (two spaces are required for a single-family dwelling). All required parking must be located on the lot where the ADU is proposed. Parking spaces may be situated in tandem. Minimum dimensions for a parking space are 9’ by 18.5’.
The total conditioned floor area of the ADU cannot exceed 850 sf.
Lots with an ADU are NOT eligible for a Short-Term Rental permit.
A Declaration of Covenants and Restrictions that includes specific restrictions on the property must be approved by the City, executed by the owner, and recorded prior to completion of construction of the ADU. See DCR Requirements tab for details.
STEP ONE: Submit ADU Application/Checklist, Site Plan, Statement, signed by the owner of the property, certifying that no covenants exist that prohibit the construction or use of an ADU on the lot, and Draft Declaration of Covenants and Restrictions, to the Zoning Desk in the Permit Center, 2 George Street.
STEP TWO: Submit a Building Permit application with all documents listed on the application to the Permit Center. Construction can begin upon issuance of a City of Charleston Building Permit.
STEP THREE: Prior to completing construction of the ADU, execute and record DCR in the appropriate County Register of Deeds Office. Provide a copy of the recorded DCR to the zoning desk. This step must be completed prior to the issuance of a Certificate of Construction Completion which permits the ADU to be occupied.
The draft DCR must be in a form sufficient for recording with the applicable County Register of Deeds Office and include the terms, conditions and provisions listed below:
1. Either the principal dwelling unit or the Accessory Dwelling Unit must be owner-occupied and serve as the primary dwelling unit for the owner of the lot. If neither dwelling unit is owner-occupied, the ADU may not be rented separately from the principal dwelling unit.
2. No subleases of the ADU shall be permitted.
3. Occupancy of an ADU shall be limited to no more than two (2) adults, with “adult” defined as any person eighteen years of age or older.
4. Under no circumstances shall the property be converted to a horizontal property regime.
5. Neither the principal dwelling unit nor the ADU shall be utilized for a short-term rental.
6. The covenants shall accord the City, or its assignee, rights to enforcement by any legal and/or equitable means, including the revocation of a certificate of occupancy.
If the applicant receives a financial subsidy from the City of Charleston and the ADU is rented for renumeration, the ADU must meet affordable housing income and rental thresholds, as defined in Sec. 54-120 , where the occupants have, in the aggregate, a household income of less than or equal to eighty percent (80%) of AMI and the owner shall provide proof of affordability to the City of Charleston Department of Housing and Community Development, or its successor, on an annual basis.
Click here for a template of an acceptable DCR if the applicant receives a financial subsidy from the City of Charleston.