 Savile Row was extended to Conduit Street in 1937 – 38 , and by 1939 , the Metropolitan Police Station was constructed on the corner of Boyle Street . This police station was damaged in another German bombing raid in September 1940 , during which the building opposite , No. 21a , was destroyed , as was No. 7 earlier that month . Fortress House , an eight @-@ storey block of offices faced with Portland stone , was constructed at 23 Savile Row in 1949 @-@ 50 and occupied by a series of government ministries , ending with a long period of occupation by English Heritage until 2006 . It was demolished in 2009 and replaced by a new mixed @-@ use development designed by Eric Parry , Architects . 
