Rockville, MD Accessory Structures: Garage Conversions (2026)

Converting a garage to habitable living space in Rockville requires a building permit from the Inspection Services Division at 240-314-8247. If the converted space will function as a separate dwelling unit, it must comply with the attached ADU regulations under zoning text amendment TXT2023-00263, including conditional use approval from the Board of Appeals. The conversion must meet the International Residential Code for habitable space including minimum ceiling height, egress windows, ventilation, insulation, and fire separation. Electrical and plumbing work requires separate trade permits. The property must maintain the minimum number of off-street parking spaces required by the zoning ordinance for the zone district. In most residential zones, two off-street parking spaces per dwelling unit are required, so eliminating a garage may trigger a need for alternative on-site parking. WSSC Water approval is required for any new plumbing connections. The structure must also meet current energy code requirements. Contact the Zoning Division at 240-314-8211 to confirm whether conditional use approval is needed for your specific project.