James Cumming Wynnes was born in Airdrie, Lanarkshire, Scotland on 29 August 1875. In 1881 he moved with his family to New Monkland, Lanarkshire. He was articled to Burnet Son & Campbell in Glasgow from 1892 to 1897. He then worked as an assistant to John Burnet & Son in Glasgow until 1899; and in the offices in Edinburgh and London of H.M. Office of Works from 1899 to 1911. During these years he appears to have also been in private practice and to have been in partnership with Gordon Lorimer Wright. From 1928 to 1938 Wynnes was employed by H. M. Ministry of Works in Japan and China.
Wynnes was elected a Licentiate of the Royal Institute of British Architects (LRIBA) in 1911 and a Fellow of the Royal Institute of British Architects (FRIBA) in 1914. He retired in 1939. He died on 20 November 1944. His address at the time of his death was given as 26 Ormond Avenue, Hampton, Middlesex
For a list of Wynnes's architectural projects see: Dictionary of Scottish Architects 1660-1980 [link below]
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
‘Obituary’. The Builder vol.167, 1 December 1944 p. 426