(Area Variance) Pursuant to 11 DCMR § 3103.2, for a variance from the building height requirements under section 400, a variance from the lot occupancy requirements under section 403, a variance from the side yard requirements under section 405, and a variance from the nonconforming structure provisions under subsection 2001.3, for an addition to an existing one-family dwelling in the R-1-B District at premises 1830 24th Street, N.W. (Square 2506, Lot 44).