This necessitated new accommodation wings, and a flanking pair to east and west were added and connected to the house by colonnades from 1807 (designed by London Docks architect Daniel Asher Alexander), with further surviving extensions up to 1876. In 1933 the school moved to Holbrook, Suffolk. Its Greenwich buildings, including the house, were converted and restored to become the new National Maritime Museum (NMM), created by Act of Parliament in 1934 and opened in 1937.