Pursuant to 11 DCMR § 3104.1, for a special exception for a rear addition to an existing one-family row dwelling under section 223, not meeting the lot occupancy (section 403), side yard (section 405), and nonconforming structure (subsection 2001.3) requirements in the R-4 District at premises 712 A Street, S.E. (Square 898, Lot 50).