Application of Robert Thorsen, pursuant to 11 DCMR Subtitle X, Chapter 9, for special exceptions under Subtitle E § 5108 from the height requirements of Subtitle E § 5102.1, the alley centerline setback requirements of Subtitle E § 5106.1, and the minimum pervious surface provisions set forth under E § 5107.1, and under Subtitle E §§ 5108 and 5204 from the rear yard requirements of Subtitle E § 5104.1, and the side yard requirements of Subtitle E § 5105.1, to construct a second-story addition to an existing alley lot structure and convert it to a detached principal dwelling unit in the RF-1 Zone at premises 775 Fairmont Street, N.W. (Square 2885, Lot 862).