The Department of Permitting Services (DPS) is located at 255 Rockville Pike, 2nd Floor, Rockville, MD 20850. Office hours of operation are 7:30 AM to 4:00 PM, Monday through Friday. The fax number is 240.777.6262. The office is closed weekends and holidays. On busy days, the walk-through permit process may be closed early to allow everyone to be served in a timely manner.