D.C. Mun. Regs. tit. 11-K, § 304
304
304.1 For the purposes of the USN zone, each platform and all improvements constructed thereon are deemed to comprise a single building.
304.2 Any part of a single building that is not connected to any other part of the same single building, other than through the structure of the platform, will be hereinafter referred to as a building unit.
SOURCE: Final Rulemaking published at 63 DCR 2447, 3176 (March 4, 2016 – Part 2).