Clue: It parallels Number Ten — as its occupants do in today's solutions (5,5)
Answer: WHITE HOUSE
Explanation: Definition: It parallels Number Ten
*Some of its (previous) occupants are running parallel to "Number 10" (ie 10 across), ie. HOOVER (15ac) and WILSON (17dn)m although most of the predientsin the puzzle run down rather than across.