Worcester County, MD Accessory Structures: ADU Rules (2026)

Section ZS 1-338 of the Worcester County Code sets the accessory apartment standards for unincorporated Worcester County, Maryland. Ocean City, Berlin, Snow Hill and Pocomoke City regulate apartments under their own codes. The stated purpose is to allow no more than one accessory apartment per lot of record, through conversion of existing residential structures or construction of new residential facilities, to meet the housing needs of persons of low and moderate income and of relatives of families already living in the County.

Size is the tightest limit. Inside the principal building the apartment must be at least five hundred square feet, and it cannot exceed thirty-five percent of the dwelling's gross floor area, exclusive of any garage, or nine hundred square feet, whichever is less. An apartment in an accessory building has the same five hundred square foot minimum and the same nine hundred square foot cap, measured against thirty-five percent of the principal dwelling's gross floor area. No accessory apartment can contain more than two bedrooms, and a manufactured or mobile home cannot serve as one.

Location rules follow. An apartment in an accessory building must sit so that its entire perimeter is within one hundred feet of the principal building. A greater separation can be approved under § ZS 1-117(e)(5), but only where the property is not in the Chesapeake or Atlantic Coastal Bays Critical Area. If the apartment is inside the principal dwelling, its entry must be designed so the building still looks like a single-family dwelling, although nothing requires the entry to be confined to the side or rear.

Infrastructure and parking come next. The Environmental Programs Division must determine that adequate wastewater disposal capacity is available. As an accessory residential use the apartment does not count against permitted density under the Article, although other regulations can require it to be counted. Off-street parking follows § ZS 1-320 and is in addition to the parking required for other uses on the site. The code's editor's note records that the former rule requiring the owner to occupy one of the units was repealed 11-17-2020 by Bill No. 20-8.