Twentieth Century
During this period the house goes through a significant period of change, moving away from private ownership and towards a range of other important uses.
World War One
During the First World War South Hill Park was used as a war work collection centre. People from surrounding villages brought woollen garments which were then sent to France.
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Sir Arthur died in 1917 and his widow continued to live in the house until she died in 1929. The estate then passed to her nephew, Major Rickman. He was the last private owner of the house and unfortunately shot himself in the gun cupboard in 1940.
World War Two
In 1940 the royal sea Bathing Hospital evacuated from Margate to South Hill Park, moving back in 1945. Dr John Coakley founded the hospital 1791. He also founded the Medical society of London in 1773.
As a Quaker he had a strong social conscience and the welfare of the poor concerned him.
Using funds supplied by the Prince Regent, he set up the hospital in Margate using sea water to cure the poor of tuberculosis. When the hospital returned to Margate it remained open until the mid-1990s and is now a development of luxury flats.
Post War: 1946
In 1946 Hunton and son of Bracknell sold the mansion and 800 acres to a New Zealander, Joseph Horn. His plans were to convert the mansion into high class residential flats. He had already converted an estate in Ascot before the second World War and wanted to repeat the process.
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Without altering the exterior, he converted the interior into different sized, self-contained flats. Some of the larger original rooms remained as communal spaces with the original hall a reception room. There was also a spacious lounge, a library and a restaurant. Horn made the conversion plans in close co-operation with the Berkshire town Planning association. An article in Ideal Home of 1948 was full of praise for the conversion work.
1952
The conversion venture wasn’t entirely successful. On 23 October 1951 an auction was held, selling off the contents of the house (see pictures). This included furniture and ornamental items. The BBC purchased South Hill Park in 1952 from South Hill Park estates. This was the company run by Horn.
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1960's

South Hill Park became part of a group of properties to provide services in the event of a national emergency. Its function was to operate as the European services section of the BBC. For this reason the BBC made plans for a control room, four studios and recording areas in the house. There were also plans for new buildings in the grounds close to the main building. These were to provide extra offices and accommodation for the 1000 staff who would be working on the site. The buildings were built to minimum austerity standards.
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By August 1958 the house was empty of all BBC property. The Bracknell Development Corporation purchased South Hill Park on 19 December 1962. South Hill Park was included in the extension of the designated new town area.
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Ferranti leased the site in 1965 and used it as offices and laboratories until early 1972. Sebastian Ziani de Ferranti (1864–1930) set up Ferranti in 1882 to manufacture the alternator. The company specialised in the application of new technology to solve problems. From 1948 they were leaders in the computer industry. Ferranti had opened a research facility in Bracknell in 1963. They developed the first European microprocessor (F-100L) in the town. They went into receivership in 1993.
