Rockville, MD Accessory Structures: Carport Rules (2026)

Carports are classified as accessory structures under Chapter 25 of the Rockville City Code and are subject to the same regulations as sheds and detached garages. A building permit is required from the Inspection Services Division at 240-314-8247. Carports must be located in the rear yard in most residential zones and are generally not permitted in front or side yards. The minimum setback from any lot line is 3 feet, with additional setbacks required for structures taller than 12 feet. The maximum height at the minimum setback is 12 feet, and no accessory building may exceed 20 feet or the height of the main dwelling. Carport footprint counts toward the maximum rear yard building coverage of 15 percent in R-150, R-200, and R-400 zones and 25 percent in all other residential zones. The structure must meet wind load and structural requirements under the International Residential Code. Attached carports may be subject to different setback requirements than detached structures. Properties in historic districts or neighborhood conservation districts may face additional design review requirements. Contact the Zoning Division at 240-314-8211 for zone-specific requirements.