Accessory Structures in Carroll County, MD (2026)

2 rules for unincorporated Carroll County, Maryland.

Verified from official government sources

Note: These county rules apply to unincorporated areas of Carroll County. If you live within an incorporated city, that city's own rules apply: see the city list below.

ADU Rules

Carroll County zoning allows one accessory dwelling unit per lot in the Residential Districts, attached or detached, under § 158.075.02(A)(2) and (6). An attached ADU is capped at 800 square feet or one-third of the principal home's floor area, whichever is greater, plus two bedrooms; a detached ADU carries no size cap but needs a subdividable lot.

Carroll County Accessory Dwelling Unit Rules

Some Restrictions

Carroll County Code of Ordinances § 158.075.02(A)(2), (6)

(2) Attached accessory dwelling units, which are subject to the following: (a) An attached accessory dwelling must have direct access from the outside. (b) Only one attached accessory dwelling is permitted on any principal dwelling unit. (c) The property owner must occupy either the principal dwelling unit or the attached accessory dwelling unit on the property. (d) The maximum size of an attac...

Full ordinance details →Official source ↗

Shed & Carport Rules

Carroll County exempts small detached sheds from a building permit only if they meet strict limits: no more than 150 square feet, built on skids so they remain movable, and kept at least five feet from the side or rear property line. Anything bigger, fixed to a foundation, or built in an easement needs a full building permit from the Bureau of Permits and Inspections.

Carroll County Shed Size and Setback Rules

Some Restrictions

Carroll County Code of Ordinances § 170.15(4)(a)

One story detached accessory structures constructed on skids and movable, used as tool and storage sheds, playhouses and other similar uses, provided the floor area is not greater than 150 square feet. Sheds must not be in drainage or utility easements or within five feet of a side or rear property line and must meet all applicable zoning, health and building code regulations.

Full ordinance details →Official source ↗

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