Howard County, Maryland, states that an ADU may operate only after the Department of Planning and Zoning approves an ADU permit based on compliance with the County Zoning Regulations. The County application page says that when the owner rents the other unit, the owner must reside in either the primary dwelling or the ADU. It also requires a rental license to rent either the primary dwelling or ADU.
The County’s published sequence is zoning approval first, rental-license application second. Rental licenses are managed by the Department of Inspections, Licenses and Permits, with Planning and Zoning reviewing zoning compliance. The County says renewal applications may be submitted directly to the licensing department. Its page notes that the ADU regulations were amended effective April 8, 2026.
Check the property and intended use
Confirm that the property is in Howard County and identify its zoning and permit status. The ADU application requires a plot plan showing applicable size and setback compliance; for a newly constructed structure, the plan must also address water conveyance and effects on neighboring properties and existing subdivision stormwater facilities. Ask the County which current rules and application materials apply to the specific project.
The page does not establish whether a specific ADU has been approved or licensed, or whether a short-term rental is allowed. Check the unit’s permit and occupancy history, rental-license status, and separate short-term-rental, tenancy, tax, insurance, title, and private-document requirements. The County’s owner-residence statement is a Howard County rule summary and should not be generalized to Maryland as a whole.