ADU rules in Myrtle Beach

Myrtle Beach's Zoning Ordinance (Appendix A of the city code) has no accessory dwelling unit, guest house, garage apartment or similar use; a full-text search of the code finds none of those terms. The single-family districts R5, R7, R8, R10 and R15 allow only a single-family dwelling, whose definition caps it at one kitchen, and Section 1603.D gives those districts a minimum lot area for a first unit only. The uses accessory to a single-family home in Section 1502.B (garage, shed, playhouse, pool and cabana, storm shelter, garden) include no dwelling, and a pool cabana may not have a kitchen or overnight lodging. A backyard cottage on a single-family lot is therefore not allowed.

There is no attached ADU or accessory apartment either, but a second unit inside or attached to a house is possible as a two-family dwelling (duplex) in the districts that allow one: permitted by right in RMM, RMH, RMH-MH, RMV, MU-M, MU-H, C7, C8, A, E, HC2, MP and IN, and as a conditional use in C6 and HC1. In RMM, RMH and RMH-MH the second unit needs 2,000 square feet of lot area beyond the 4,500 for the first. The ordinary single-family districts (R5 through R15), which cover most neighborhoods, allow no second unit at all.

Because the code has no accessory dwelling use, it has no ADU size limit. Where a second unit is allowed as part of a two-family dwelling, the ordinary dimensional standards in Section 1603 apply. In RMM, RMH and RMH-MH that means a 5,000 square foot minimum lot, 50 foot width, 35 foot height and 42 percent building coverage. Section 1603.D requires 4,500 square feet of lot area for the first unit and 2,000 for the second. In RMV the height limit is 55 feet with 50 percent coverage and no per-unit lot area.

The zoning code imposes no owner-occupancy requirement on two-family dwellings, the only route to a second unit on a lot, and it has no ADU provision that could carry one. The term 'family' (no more than five unrelated persons) limits each unit's household, not who owns it.

Section 1006.D sets the minimum off-street parking. Single-family homes need 2 spaces per dwelling unit. Two-family and multifamily dwellings need 1 space per 600 square feet of gross floor area, excluding yards, up to 3 spaces per unit. One- and two-family dwellings are exempt from the parking surface rules in Section 1003, and their spaces may open directly onto a street.

No ADU permit exists. Where a two-family dwelling is a 'P' use in Section 1407.C, it is built by right with a zoning and building permit. In C6 and HC1 it is a 'C' conditional use, which Section 1407.B.2 treats as allowed once the Article 15 standards are met (1501.JJ: attached to or above nonresidential uses), with no board hearing. An 'S' use goes to the Board of Zoning Appeals, but no two-family entry is marked 'S'. Putting a second unit on an R5 to R15 lot would require City Council to rezone the lot, which is a legislative act and not a permit.

Section 203 defines a visitor accommodation ('aka "short term rental"') as any unit rented for less than 90 continuous days and makes it a commercial use. Section 1407.C allows visitor accommodations only in RMV, MU-H, C6, A, E, HC1 and HC2, and in IR by special exception. A duplex unit in RMM, RMH or the R districts can be rented only for 90 days or more. The city's Planning and Zoning page says only 24 houses in traditional residential zones are grandfathered, a business license is required where short-term rental is allowed, and violations are misdemeanors (up to $500 and/or 30 days). Section 1808, the Short-Term Rental Conversion overlay (Ord. 2024-69, December 2024), is the reverse rule: in commercial districts east of Kings Highway it bars converting buildings of more than two visitor-accommodation units to rentals of 90 days or more.