D.C. Mun. Regs. tit. 11, r. 11-H409
The street wall of each new building fronting on Blair Road, N.W., Cedar Street, N.W., and Carroll Street, N.W., or any addition to an existing building frontage on any of these streets, shall setback for its entire height and frontage not less than thirteen feet (13 ft.), measured from the adjacent curb line.
Except as provided in Subtitle H § 409.4, the ground floor level of each new building or building addition shall have a minimum clear floor-to-ceiling height of fourteen feet (14 ft.).
Those portions of buildings with a minimum clear floor-to-ceiling height of fourteen feet (14 ft.) on the ground floor level shall be permitted a total building height of fifty-five feet (55 ft.).
Buildings occupying or constructed on lots along the Blair Road frontage of Square 3187 and Cedar Street frontage of Squares 3352 and 3353 within the NC-2 zone do not have to provide the designated retail and service establishments on the ground floor level required by Subtitle H § 1101.1, nor comply with the ground floor level floor-to-ceiling height requirement of Subtitle H § 409.2, if the ground floor level is devoted exclusively to residential uses.
If ground floor residential uses are established pursuant to Subtitle H § 409.4, no certificate of occupancy for a permitted non-residential use on the ground floor level may be issued, unless the ground floor level of the subject building complies with the floor-to-ceiling height requirement of Subtitle H § 409.2.
D.C. Mun. Regs. tit. 11, r. 11-H409