502.1 The maximum permitted height of a penthouse or rooftop structure, except as limited in Subtitle C § 1501 on the roof of a single household dwelling or flat, shall be twelve feet (12 ft.); except fifteen feet (15 ft.) shall be permitted for penthouse mechanical space, and the maximum number of stories shall be one (1).

502.2 A penthouse or rooftop structure permitted by this section shall contain no form of habitable space, other than ancillary space associated with a rooftop deck.

SOURCE: Final Rulemaking published at 63 DCR 2447, 2944 (March 4, 2016 – Part 2); as amended by Final Rulemaking published at 66 DCR 13705 (October 18, 2019); as amended by Final Rulemaking published at 68 DCR 013904 (December 24, 2021); as amended by Final Rulemaking published at 70 DCR 011297 (August 25, 2023).