D.C. Mun. Regs. tit. 11-I, § 204
204.1 A front setback shall be measured from each property line adjacent to a public street on which the building has frontage, unless the setback measuring line is otherwise specified for a designated street segment within the Mount Vernon Triangle Principal Intersection, Pennsylvania Avenue, South Capitol Street, or Independence Avenue, sub-areas in Subtitle I, Chapter 6.
SOURCE: Final Rulemaking published at 63 DCR 2447, 3041 (March 4, 2016 – Part 2).