Lionel Gordon Detmar was born in Epsom, Surrey, England on 1 July 1879. He was articled to his uncle, Walter Hilton Nash (1850-1927) from 1896 to 1899 and was an improver with John Belcher (1841-1913) in 1899-1900. He then worked as an assistant to Leonard Aloysius Scott Stokes (1858-1925) and to James Glen Sivewright Gibson (1861-1951). He also attended the Royal Academy Schools in London.
Detmar qualified as an architect in 1901 and was elected an Associate of the Royal Institute of British Architects (ARIBA) later that year. He subsequently practised as an architect in London and was in partnership with his uncle until 1905. He then formed Gregg & Detmar, a partnership with Theodore Gregg (1876-?). Their office was located at 1a St. Helen's Place, London.
Detmar was awarded the RIBA Gold Medal in 1901 and was one of the three architects chosen to design the British Section at the Franco-British Exhibition in London in 1908.
His address was given as Arthur House, Arthur Road, Margate, Kent in 1891; and Hazeldean, Benhilton, Epsom, Surrey in 1901 and 1910. He died in the Cottage Hospital in Epsom, Surrey, as a result of a horse riding accident, on 9 April 1910.
With Gregg: Maida Vale American Skating Palace [later BBC Maida Vale Studios,] Delaware Road, London in 1909-10.
'Maida Vale Rink Opened'. The Era, 26 February 1910, p. 27
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
Gray, A. Stuart. Edwardian architecture: a biographical dictionary. London: Gerald Duckworth & Co., Ltd., 1985
‘Obituary’. The Builder vol. 98, 16 April 1910 p. 444
‘Obituary’. RIBA Journal vol. 17, 23 April 1910, p. 492