Contact For more information about the Zoning Handbook please contact the District of Columbia Office of Zoning. Office Hours Monday to Friday, 8:30 am to 5:00 pm Office of Zoning Government of the District of Columbia 441 4th Street NW Suite 200S Washington, DC 20001 Phone: (202)727-6311 Fax:(202)727-6072 Email: zr16@dc.gov