Harold Percy Williams [also known as H. Percy Williams] was born in Halifax, Yorkshire, England on 2 July 1878. He was articled to his father, William Clement Williams (1845–1913), in Halifax in 1896 and remained with him as his assistant. He also attended Bradford Technical College. He commenced independent practice as an architect in Halifax in 1909 and from 1909 to 1913 was in partnership with his father and brother, Ralph Eustace Williams (1887–1918), in Halifax. From c.1914 he was in partnership with his sons as Clement Williams & Sons
He was elected a Licentiate of the Royal Institute of British Architects (LRIBA) in 1912 and was admitted a Fellow of the Royal Institute of British Architects (FRIBA) in 1947. His address was given as 15 Akeds Road, Halifax in 1901 and 1912; Post Office Buildings, Commercial Street, Halifax in 1912 and 1914; Althorpe, Halifax in 1912 and 1939; Permanent Chambers, Commercial Street, Halifax in 1923 and 1939; and Greenroyd, Green Walk, Seaford, Sussex in 1950 He died on 15 August 1950
Clement Williams & Sons: — Victoria Concert Hall; St. Luke's Hospital; York Buildings; Victoria Buildings; Post Office Buildings; Workhouse Administration Offices; Arcade Royale; Café Royale; head offices for the Halifax Permanent Building Society; shops and office block. Fountain Street; extensions, Co-operative Stores; Sunnyside Schools; extensions to Christ Church, Pellon; extensions to St. Marie's Church; all at Halifax. Orient Cafe, Port Erin, Isle of Man; Orient Cart aad Greensills Corner Cafe, Douglas, Isle of Man; new P.M. Church, Port Erin, Isle of Man; Baptist Schools, Rishworth, near Halifax; Liberal Club, Ripponden; Hole In Wall Hotel. Hobden Bridge; Penny Bank, Sowerby Bridge; Barkisland Mills, near Halifax; Messrs. Pollitts and Wigzells engine works and offices; Cooper House Hills, Luddenden Foot; warehouses and dyehouse, Clark Bridge Milk; Wellington Mills: West Croft Mills; Royal Mills; all at Halifax; many other mills in that city and elsewhere. Women's Hostel, Triangle; Housing for Ripponden Commercial Co.; extensive works, Tasmania; also at Leeds, Buxton, Blackpool, Preston, Huddersfield, etc. Laying out several estates, and erecting blocks of dwelling houses, etc., Shaw Lodge, Halifax; a considerable number of residences in Halifax and district, also at Harrogate, Silverdale, Port Erin, Pontefract, Oxford, and Settle
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