Maryland adopts its building codes statewide and leaves zoning to Baltimore City, the 23 counties and the incorporated towns. The container's size, its use and the address decide which office answers and what it asks for.
The Maryland Building Performance Standards adopt the 2021 International Building Code, the 2021 International Residential Code and the 2021 International Energy Conservation Code, effective May 29, 2023 (COMAR 09.12.51). A county or city may amend the standards for local conditions, and the regulation puts enforcement locally:
"Enforcement of the Standards shall be the responsibility of the local jurisdiction in which the building or structure is located."
The state's Building Codes Administration has proposed moving to the 2024 editions, with the proposal published in the Maryland Register on June 26, 2026 (Building Codes Administration news). The office that takes your application will tell you which edition it applies.
Whether a container may sit on a lot, where it may sit and for how long are answered by Baltimore City, by the county, or by an incorporated town that runs its own zoning.
The 2021 International Building Code has its own section for containers that become buildings. Section 3115.1 reads:
"The provisions of Section 3115 and other applicable sections of this code shall apply to intermodal shipping containers that are repurposed for use as buildings or structures, or as a part of buildings or structures."
The residential code points to the same place. Section R301.1.4 of the 2021 International Residential Code says repurposed containers "shall be designed in accordance with the structural provisions in Section 3115 of the International Building Code" (2021 IRC, Chapter 3). Baltimore City's building code adopts Section 3115 as written in the model code (Building, Fire, and Related Codes, Section 3115).
A container used as an office, a workshop or a home falls under these sections. A container that only holds tools, stock or household goods raises the local questions below: the zoning rules for accessory structures and the size at which a building permit applies.
A container's footprint. A 20ft container covers 160 square feet, 8 feet by 20 feet. A 40ft container covers 320 square feet.
Four local offices publish these rules for storage sheds:
| Office | Published rule for storage sheds |
|---|---|
| Baltimore City | One-story detached tool and storage sheds are exempt from a building permit only up to 120 square feet (Work Exempt From Permit) |
| City of Annapolis | On residential property, a shed under 200 square feet needs a zoning certificate, and a shed over 200 square feet needs a building permit (Shed Building Requirements) |
| Anne Arundel County | Sheds no taller than 10 feet with 150 square feet or less of floor area need no building permit, except in the Critical Area, where every shed needs one (Do I need a Permit?) |
| Frederick County, outside the City of Frederick and Mount Airy | Residential accessory structures under 150 square feet need no building permit (Residential Building Permit Information) |
A 20ft container is larger than the Baltimore City, Anne Arundel County and Frederick County limits, and a 40ft container is larger than all four. Each office decides whether its shed rule covers a container, so describe the container and its use when you ask.
Baltimore's zoning code treats the drop-off and pickup kind of storage unit as a temporary use. Section 14-415 defines a temporary storage container as one "delivered to a residential or commercial use for the resident or business owner to store belongings, which are then picked up and returned to a warehouse until called for." Those units are allowed in any zoning district for loading or unloading, may not be used for permanent storage, and are "limited on site to a period of not more than 72 hours" (Article 32, Section 14-415).
A container you buy stays on the lot, so ask the Office of the Zoning Administrator how the city will review it. The office issues zoning authorizations and use permits from Room 147 of the Benton Building, 417 E Fayette Street (Office of the Zoning Administrator). Under the accessory structure rules, an accessory structure must be on the same lot as the main building, all accessory structures together may cover no more than 50% of a required rear yard, and an accessory structure is generally limited to 15 feet in height (Article 32, Section 15-501).
Building permits run through the Department of Housing and Community Development's E-Permits system, and the Permits Office answers at 443-984-1809 (DHCD Building Permits).
A container set on a street, sidewalk or alley needs a different permit. The Department of Transportation's Right of Way Permit Section issues temporary use of right of way permits for storage containers, dumpsters and moving trucks, and it gives 15 days as the standard processing time (Right of Way Permits).
Baltimore has 38 local historic districts (Commission for Historical and Architectural Preservation). Inside one, "the construction or erection of any exterior building, fence, wall, or other structure of any kind" needs a permit from the Building Official (Article 6, Section 8-2), and that permit cannot issue until the commission's director grants an Authorization to Proceed (Article 6, Section 8-4). The commission's office number is (410) 396-7526.
An Annapolis mailing address can be inside the city or out in Anne Arundel County, and the two have separate offices. Inside the city, the Department of Planning and Zoning handles permits, zoning, Critical Area compliance and historic preservation from 145 Gorman Street, 3rd floor, at 410-260-2200 (Planning, Zoning and Building).
In the Annapolis Historic District, the city's Historic Preservation Division reviews exterior changes and asks owners to "submit applications for review and approval before signing a contract or starting the work" (Historic Preservation Division).
Outside the city, Anne Arundel County Inspections and Permits is at 2664 Riva Road, at (410) 222-7730, and Zoning Administration answers at 410-222-7437 (Permits; Zoning Administration).
Inside the City of Frederick, the Land Management Code defines a portable storage container as "a standardized, reusable vessel" originally or formerly designed for or used in shipping freight, which covers shipping containers (Section 1002). Section 803(f) then sets these limits:
Read the full section on the city's code site (Land Management Code, Section 803). The Planning Department answers at 301-600-1499 and Building Permits at 301-600-3808 (Planning; Building Permits). In a Historic Preservation Overlay, the Historic Preservation Commission must approve all exterior work except minor rehabilitation (Historic Preservation).
Outside the city, Frederick County's Department of Permits and Inspections issues zoning certificates and building permits everywhere except the City of Frederick and Mount Airy, at 301-600-2313 (Permits and Inspections). Its residential permit sheet says accessory structures may not go in the required front yard, and on residentially zoned land outside the incorporated towns an accessory structure may be 600 square feet of footprint or less, or half the footprint of the house. The county's zoning reviewer, at 301-600-1143, confirms which limit applies to a lot. Incorporated towns may require their own zoning certificate (Residential Building Permit Information).
Maryland law draws the Critical Area around the Chesapeake Bay and its tidal tributaries, including "all land and water areas within 1,000 feet beyond the landward boundaries of State or private wetlands and the heads of tides" (Natural Resources Article, Section 8-1807). Inside it, a minimum 100-foot buffer runs landward from tidal waters, tributary stream banks and tidal wetlands, and Anne Arundel County says disturbance in that buffer generally needs an approved variance (Anne Arundel County, Critical Area).
Ask about it early if the property is on a creek, a river or the Bay itself.
Container One requires 110 feet of straight, unobstructed space for a 20ft container and 130 feet for a 40ft, at least 15 feet of height to drive, at least 22 feet of height along the entire unloading path and at least 10 feet of width (Container One FAQ). Measure these clearances along the truck's route onto your property and the entire unloading path.
This guide is general information about how Maryland offices handle containers, and codes change. Confirm the requirements for your address with the office that governs it before you order.