ADU rules in Maryland
Representative cities: Baltimore, Annapolis.
ADU permit rule
Permit requiredCase by casecity authority
Fee basis
Building permit fee set by the city; zoning/use approval also required.
Typical timeline
Varies
Setback
—
Area threshold
Not size-exempt
Exempt if
Not exempt
Go / no-go
case-by-case
ADUs require a building permit and local zoning approval. Maryland’s MBPS governs construction; local zoning controls whether an ADU is allowed. Verify with Baltimore DHCD or Annapolis Planning & Zoning.
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Frequently asked questions
Do I need a permit to build an ADU in Maryland?
Per Maryland rules, an ADU is "yes" for a permit and the authority is "city". ADUs require a building permit and local zoning approval. Maryland’s MBPS governs construction; local zoning controls whether an ADU is allowed. Verify with Baltimore DHCD or Annapolis Planning & Zoning. Always confirm with the issuing building department.
How big can an ADU be in Maryland?
Size limits for an ADU in Maryland are set by local zoning — verify with your city building department.
What are the ADU setbacks in Maryland?
Setback rules vary by city in Maryland; confirm with the local planning or building department.
How much does an ADU permit cost in Maryland?
Fee basis: Building permit fee set by the city; zoning/use approval also required.