5480.1 The maximum permitted building height, not including the penthouse or rooftop structure, in the D-5-R zone shall be as follows:

Street Right-of-Way Width	Maximum Permitted Building Height, Not Including Penthouse or Rooftop Structure
Greater than or equal to 110 ft.	130 feet
Less than 110 ft. but greater than or equal to 100 ft.	120 feet
Less than 100 ft. but greater than or equal to 90 ft.	110 feet
Less than 90 ft.	No taller than the width of the street right of way, plus 20 feet

5480.2 A building on a lot in the D-5-R zone with frontage on one (1) or more of the following designated street segments shall also be subject to the exterior height regulations governing the sub-area in which the segment is located:

1. (a) The Massachusetts Avenue Corridor and Mt. Vernon Square Sub-Area regulations in Subtitle I § 610 apply to properties fronting Massachusetts Avenue, or Mount Vernon Place N.W., between 6th and 10th Streets, N.W.; and
2. (b) The Mount Vernon Triangle Principal Intersection Area Sub-Area regulations in Subtitle I § 612, governing exterior and interior heights, apply to properties fronting portions of the intersection of 5th and K Streets, N.W.

548.3 The maximum permitted building height, not including the penthouse or rooftop structure, in the D-5-R zone shall be limited to ninety feet (90 ft.) on the portion of the site occupied by a historic landmark or a contributing building within a historic district.

548.4 The maximum permitted height of a penthouse or rooftop structure shall be twenty feet (20 ft.). The maximum permitted number of stories for penthouse habitable space shall be one (1) plus a mezzanine, except a second story shall be permitted for penthouse mechanical space.

SOURCE: Final Rulemaking published at 63 DCR 2447, 3041 (March 4, 2016 – Part 2); as amended by Final Rulemaking published at 63 DCR 10932 (August 26, 2016); as amended by Final Rulemaking published at 68 DCR 013834 (December 24, 2021).