D.C. Mun. Regs. tit. 11-H, § 706
706.1 In the NMU-7B/ES zone, 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 as permitted in Subtitle H § 706.2.
706.2 In the NMU-7B/ES zone, the maximum permitted height of a penthouse for mechanical space shall be fifteen feet (15 ft.).
706.3 The maximum number of stories for a penthouse or rooftop structure shall be one (1).
SOURCE: Final Rulemaking published at 63 DCR 2447, 2987 (March 4, 2016 – Part 2); as amended by Final Rulemaking published at 70 DCR 011297 (August 25, 2023).