Rock Hill, SC Accessory Structures: ADU Rules (2026)

2(A) of the Zoning Ordinance of the City of Rock Hill sets the baseline standards for accessory dwelling units on single-family detached lots. Mobile homes, manufactured homes, recreational vehicles, and travel trailers are flatly barred from serving as an ADU; the unit has to be a permanent structure that meets at least 480 square feet. A lot gets no more than one ADU in addition to the principal single-family home, and it must carry at least one off-street parking space for every bedroom the ADU contains, on top of whatever parking the main house already needs.

ADUs do not count toward any maximum residential density limit that would otherwise apply to the lot. An ADU also cannot be sold apart from the principal dwelling; the two stay under one deed. 2(A)(10) folds in every other standard that applies to principal dwelling units in whatever zoning district the lot sits in, covering things like height and setbacks through the base district rules rather than a separate ADU table. Two further conditions, who has to live on the property and how the unit can be rented out, are set out in their own subsections and carry real restrictions of their own. Because the Zoning Ordinance was last updated in June 2026, these are current standards, not the superseded pre-2026 baseline.