D.C. Mun. Regs. tit. 11, § 3312
3312.1 Rooftop penthouses not intended for human occupation, such as penthouses over mechanical equipment, a stairway, or an elevator shaft shall be erected or enlarged pursuant to § 411 of this title.
SOURCE: Final Rulemaking published at 60 DCR 4834 (March 29, 2013).