D.C. Mun. Regs. tit. 11, § 1724
1724.1 Except for buildings in Square 515, the portion of a building within an 'A' module shall be no higher than fifty (50) feet above grade.
1724.2 No more than fifty percent (50%) of the portions of a building within each of the 'B' and 'C' modules shall be more than fifty (50) feet above grade.
SOURCE: Final Rulemaking published at 53 DCR 7860 (September 29, 2006).