William Henderson Duncan was born in Dundee, Forfarshire, Scotland on 4 January 1854 and was articled to Alexander Johnston in Dundee from 1870 to 1874. From 1874 to c.18881 he worked as an assistant to John Carver (1834-1896) and Robert Keith (1848-1914) in Dundee and to James Cheetham in Rochdale, Lancashire. In 1881 or 1882 - sources differ] Duncan established his own independent practice in Rochdale, Lancashire. In 1891 he formed an architectural partnership with Edward Simpson Butterworth (1841-1923).
Duncan was elected a Fellow of the Royal Institute of British Architects (FRIBA) in 1904. He was also a Fellow of the Manchester Society of Architects. He died in Rochdale, Lancashire on 17 February 1928.
"Denehurst", Rochdale; Infirmary, Rochdale ; cottage homes, Rochdale; Grand Hotel. Morecambe; Rochdale Reform Club; Rochdale Infirmary extensions; Liberal Clubs at Norden and Whitworth; Central Schools, Rochdale; King George V. Hotel, Bacup; Crown Hotel, Rawtenstall; Empire and Palace Theatres, Rochdale; Hippodromes at Bolton and Altrlngham; Pavilion Picture Palace, Rochdale; extensive works for Turner Bros., Ltd., Rochdale; Asbestos Works, Trafford Park; Jam works, Ely, Cambs; Spotland United Methodist Church; Milnrow Free Library; Central Premises, Rochdale Provident Soc, Ltd.; General Offices Rochdale Equitable Pioneers Soc, Ltd.
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