A container home in Maryland follows the path of any new house: the statewide residential code, the local zoning for the lot, a foundation designed for the ground under it and a delivery route the truck can use.
Maryland's Building Performance Standards adopt the 2021 International Residential Code for one- and two-family homes, effective May 29, 2023, and local building departments enforce them (COMAR 09.12.51). The residential code addresses containers directly in Section R301.1.4:
"Intermodal shipping containers that are repurposed for use as buildings or structures shall be designed in accordance with the structural provisions in Section 3115 of the International Building Code."
Section 3115 of the 2021 International Building Code asks for construction documents that establish the properties of the container's steel and its wood floor. Each container needs its existing data plate, with details such as the manufacturer, the date of manufacture and the allowable stacking load, verified by an approved agency, and the agency's report goes to the owner. A container used as a permanent building sits on a foundation designed under the code's structural chapters (2021 IBC, Section 3115).
Maryland's standards also adopt the residential code's appendix for tiny houses, Appendix AQ (COMAR 09.12.51.04). If the plan is a small home built from one container, ask the building department whether it reviews the project under that appendix.
The energy code applies too. Most of the state is in Climate Zone 4A, and Allegany and Garrett counties are in Zone 5A (2021 IECC, Table R301.1). A steel wall needs more insulation than a wood wall to reach the same energy code rating. Our guide to insulating a container in Maryland gives the code's insulation values and its vapor retarder rules. A 40ft high cube has about a foot more interior height than a standard container, which leaves room for insulation and a finished ceiling.
Some container homes are finished in a factory and delivered as modules. Maryland calls a building made that way an industrialized building, one "manufactured in its entirety, or in substantial part, off site and transported to a site for installation or erection." The state's standards for modular homes pre-empt local building codes. An approved modular home carries green state certification labels, generally inside the cabinets under the kitchen sink (Maryland Department of Labor, What is a Modular Home?).
Local offices still inspect the installation and the on-site work, including the foundation and anchorage, and zoning and site preparation stay under local authority (Industrialized/Modular Buildings General Description).
Under Section 4-104(d) of Maryland's Land Use Article, a local legislative body may not prohibit placement of a new manufactured home or modular dwelling in a zone allowing single-family homes if it meets one of the following three conditions (Land Use Article, Section 4-104). The first is that it qualifies as a modular dwelling: it must be designed for habitation, include the necessary electrical, plumbing, heating, ventilation and other service systems, and be made or assembled by a manufacturer on or off the building site for installation there. It must be installed and set up according to the manufacturer's instructions on an approved foundation and support system. The second is that it qualifies as a manufactured home and is, or becomes after purchase, real property. Under Section 9-102(a) of the Commercial Law Article, a manufactured home must be transportable in one or more sections and built on a permanent chassis. Its body must be at least 8 feet wide or 40 feet long during transport, or the structure must cover at least 320 square feet when erected on site. It must be designed for use as a dwelling when connected to the required utilities, with or without a permanent foundation. Under Title 8B, Subtitle 2 of the Real Property Article, the home becomes real property when it is attached to a permanent foundation, the home and land have the same owners with identical ownership shares, and a sworn statement of attachment (an affidavit of affixation) has been recorded with the clerk of the court in the county where the land is located. The third condition is that the home or dwelling is on land larger than 80 acres that is currently or previously federally owned and was a former U.S. military reservation. Section 1-401 also applies this protection to Maryland's charter counties: Anne Arundel, Baltimore, Cecil, Dorchester, Frederick, Harford, Howard, Montgomery, Prince George's, Talbot and Wicomico (Land Use Article, Section 1-401). For a Baltimore City address, call the Office of the Zoning Administrator at 410-396-4126 to ask whether your proposed container home qualifies. Elsewhere in Maryland, ask your county's zoning office, or your incorporated town's zoning office if the town has its own zoning, whether your proposed container home qualifies.
Zoning decides whether a home can go on the lot, where it can sit and how large it can be. In Maryland that answer comes from Baltimore City, the county, or an incorporated town that runs its own zoning. Historic districts add a design review: Baltimore has 38 local historic districts (Commission for Historical and Architectural Preservation), the Historic Preservation Division in Annapolis asks you to apply for approval of exterior changes in the Historic District before signing a contract or starting work (Historic Preservation Division), and Frederick's Historic Preservation Commission must approve exterior work in its historic overlays (City of Frederick, Historic Preservation).
Covenants recorded for a neighborhood are separate from zoning and can include architectural rules on materials and appearance. Read them before the design starts.
A permanent home needs a foundation below the local frost line, and each jurisdiction sets that depth in its design table. Baltimore City and Anne Arundel County both list 30 inches (Baltimore City Table 301.2(1); Anne Arundel County). The table posted for Garrett County lists 36 inches (Garrett County design table).
Ask the county or city early about two ground conditions. The Maryland Geological Survey lists karst, the limestone and dolomite terrain where sinkholes form, in Baltimore, Carroll, Washington and Frederick counties, and names the Hagerstown, Frederick and Wakefield valleys as the areas most associated with collapse sinkholes (MGS, Sinkholes). In the Coastal Plain, the Marlboro Clay is one of the formations highly susceptible to slope failure, and the survey reports such failures as particularly numerous in southwestern and east-central Prince George's County (MGS, Marlboro Clay).
Near the water, the Chesapeake Bay Critical Area covers land within 1,000 feet of tidal waters and tidal wetlands (Natural Resources Article, Section 8-1807). Its minimum 100-foot buffer limits building close to the shoreline, and Anne Arundel County says disturbance in the buffer generally needs an approved variance (Anne Arundel County, Critical Area).
On a lot with a well and a septic system, the health department's rules shape where the home and any outbuilding can go. Frederick County's permit sheet, for example, says accessory structures may not be located within designated septic areas and that a foundation within 30 feet of a well is not permitted unless a variance is granted (Frederick County, Residential Building Permit Information). Ask the county about the septic area and the well setback before you pick the spot.
Container One's most common delivery method is the tilt bed, which slides the container off the back of the trailer onto the ground. Setting a container onto raised piers or a foundation wall takes lifting equipment, and on a flatbed delivery Container One says the customer provides the crane, forklift or other heavy equipment that lifts it off the trailer (Container One FAQ).
Either way the route has to fit the truck: 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.
This guide is general information, and codes change. Confirm the requirements for your lot with the local zoning and building offices and a design professional before you order.