Sydney Ernest Castle was born in Battersea, London on 9 July 1883. He trained with H. W. Edwards, a surveyor and worked as chief assistant to Arthur Jessop Hardwick (1867-1948) before establishing his own practice in London in 1908. From 1908 to 1918 he was in partnership with Gerald Warren (1881-1936) as Castle & Warren. He worked on St. George's Hill Estate in Weybridge, Surrey with Walter George Tarrant (1875-1942).
Castle was elected a Fellow of the Royal Institute of British Architects (FRIBA) in 1925. His address was given as The Studio, Louvaine Road, New Wandsworth, London in 1903 and 1905; 259 Burntwood Road, Wandsworth Common, London in 1915 and 1930; 40, Albemarle Street, Piccadilly in 1926; and 269 Burntwood Lane, Wandsworth, London; and 169 Regent Street, London in 1939. He died in Wandsworth, London on 24 March 1955
In partnership prior to 1914: Deptford Library; new factory and works, Pitsea, Essex; newspaper buildings, Fleet Street, E.C.; and various domestic buildings. In personal practice since 1918: Premises, Christian Association, Clapham; E.C. Schools, Balham, S.W.; 6, Curzon Street, W.1; motor works, 20, Clarges Street, W.1, and 18, Down Street, W.1; motor offices, 1, Brick Street, W.1; 14, South Audley Street, W.1; 94, George Street, W.1; new private hotel, Old Brompton Road; aerodrome buildings, S.E. Area Camps; residences at Mitcham, Addiscombe, Richmond, Pulborough. Chigwell, Wallington, Leatherhead, Purley, Coulsdon, Sutton, Croydon, Grange Hill, East Sheen, Deal, Shirley and Worplesdon; and business premises, Harrow. [Source: Who's Who in Architecture 1926]
Castle, Bruce. ‘Sydney Ernest Castle (1883-1955) Architect, Author & Illustrator’. The Thirties Society Journal no.4, 1984 pp.16-25
Castle, Sydney Ernest. Domestic Gothic of the Tudor Period.Jamestown, N.Y.: International Casement Company, Inc., 1927
‘Obituary’. The Builder vol. 188, 29 April 1955 p. 712
‘Obituary’. RIBA Journal vol. 62, August 1955 p. 430
Directory of British Architects 1834-1914. Compiled by Antonia Brodie, et al. Volume 1: A-K. London; New York: British Architectural Library, Royal Institute of British Architects/Continuum, 2001
Who's Who in Architecture 1926. Edited by Frederick Chatterton. London: Architectural Press, 1926