Best accessory dwelling unit — Baltimore, MD

Last updated: September 24, 2026

What affects the price

Building an ADU involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.

About this service

Frequently asked in Baltimore

Also serving nearby: Washington · Alexandria · Reading · Philadelphia · Allentown

All cities in Maryland →

More on this: HUD ADU resources — ADU policy and financing research.

Service area details

Serving all of Baltimore — population 565,239; about 6,982 residents per square mile across 80.9 sq mi. ZIP codes covered include 21201, 21202, 21203, 21205, 21206, 21209, 21210, 21211.

Neighborhoods served in Baltimore: Federal Hill, Canton, Fells Point, Hampden, Inner Harbor, Mount Vernon — and every surrounding area.