Harold Albert Thomerson was born in Shoreditch, London, England on 31 August 1889 and was articled to H. W. French. He also attended the Architectural Association Schools in London. He subsequently practised as an architect in London. He was in partnership with Walter George Whincop (1888-1961) in Stoke Newington in c.1912, with Herbert Shepherd (1873-1944) from 1928 to 1935, and with B. Cowser from 1946 to 1948.
Drawings and plans of a house designed by Whincop and Thomerson are illustrated in Designs for One Hundred Ideal £1,000 Houses. Being copies of the hundred best designs entered in the 1912 Daily Mail Architects' Competition (1912 p.116).
Thomerson was elected an Associate of the Royal Institute of British Architects (ARIBA) in 1919. His address was given as 74, Filey Avenue, Stoke Newington, London in 1912; 36, Formosa Street, Warwick Avenue, Maida Hill,. London in 1923; "Redcot", Yiewsley, Middlesex in 1926 and 1928; 11 Lawn Avenue, Hillingdon, Uxbridge in 1933; Ruffetts", 8 The Meads, Church Road, Cowley, Middlesex, and 42 Queen's Road, Bayswater, London in 1939. He died in Uxbridge in 1948
Directory of British Architects 1834-1914. Compiled by Antonia Brodie, et al. Volume 2: L-Z. London; New York: British Architectural Library, Royal Institute of British Architects/Continuum, 2001