D.C. Mun. Regs. tit. 11-B, § 322
322.1 The provisions of this chapter do not require a court, but regulate its minimum required dimensions where they exist.
322.2 Where a court is open to a yard or any lot line, the court width requirements apply only to the dimension that is parallel or nearly parallel to the opening.
322.3 Court width requirements are expressed as a ratio of required width to height of a court. The height of a court is measured from the base of the court, even where the base may be on an upper story of a building.
322.4 If the court is not rectangular, the width shall be the diameter of the largest circle that may be inscribed in a horizontal plane within the court.
SOURCE: Final Rulemaking published at 63 DCR 2447, 2650 (March 4, 2016 – Part 2).