Harford County, MD Accessory Structures: Shed & Carport Rules (2026)

Harford County's zoning code treats a shed or detached garage as an accessory structure under § 267-4, defined as a structure customarily incidental and subordinate to the principal use on the same lot. Before building one, the owner must get a zoning certificate under § 267-27B, which applies to every accessory structure whether or not the specific type is separately listed. Size is capped by district: § 267-27C(1) limits an accessory structure in the AG, RR, R1, R2, R3, R4 and VR Districts to 50% of the principal house's total square footage or 1,000 square feet, whichever is greater, and its height cannot exceed the principal structure's height.

On AG parcels larger than 5 acres, the cap rises to 2,500 square feet or 50%, whichever is greater, and height can reach 115% of the principal structure's height. Setbacks depend on lot type: § 267-27C(6)(b) requires residential detached accessory structures to sit at least 3 feet from side or rear lot lines, shrinking to zero feet for townhouse and zero-lot-line lots under § 267-27C(6)(c), while agricultural lots need a 10-foot setback under § 267-27C(6)(a). A shed cannot go up before the main house is substantially complete (§ 267-27C(3)), cannot be used as living quarters or for running a business (§ 267-27C(2)), and cannot push the lot's impervious surface past the maximum allowed (§ 267-27C(4)).

15 per square foot plus a $100 non-refundable application fee at 200 square feet and larger, or a flat $20 with no certificate of occupancy or inspection required under 200 square feet, per § 157-16A.