The Courtaulds moved into their new house in 1933 and stayed there until May 1944 when they finally decided to move away from London because of the bombing. The house was leased to the Royal Army Educational Corps as a base from which it ran army schools overseas and administered examinations. The RAEC remained at Eltham until 1992.
The house passed to the Ministry of Works. A programme of repairs was carried out and it was opened to the public with the focus on the medieval remains on the site. English Heritage acquired responsibility for the Great Hall in 1984 and for the whole site in 1995 and set about a major refurbishment plan for the 20th century part of the property, the first stage of which took 5 years. A further set of rooms were opened to the public in 2013 following refurbishment.