During its 2025 session, the Maryland General Assembly passed HB 1466 (“Accessory Dwelling Units – Requirements and Prohibitions”), which codifies state policy supporting development of Accessory Dwelling Units (ADUs), effective October 1, 2025. It also requires that counties and municipalities with planning and zoning authority adopt a local law authorizing ADU development on land with a single-family detached dwelling unit by October 1, 2026. ADU Bill (HB 1466) FAQ
Common ADU Types ADUs are smaller, independent dwelling units, attached or detached, located on the same lot as a stand-alone single-family home. ADUs can be converted rooms in existing homes (interior ADUs), additions (attached ADUs), or new/converted stand-alone accessory structures (detached ADUs). With the bill’s passage, it is the policy of the state of Maryland to promote and encourage ADU development on land with a primary single-family detached dwelling unit to help meet the state’s housing needs. ADUs also advance the state’s Sustainable Growth Policy and Planning Principles, which endorse a mix of quality housing types and affordability options to accommodate all who want to live in the state.
MDP has developed several resources supporting local governments in implementation of HB 1466, including a model ordinance. For information, suggestions, or requests, please contact Carter Reitman, Lead Housing Planner for the Maryland Department of Planning, at [email protected].
