Had one of the longest established offices in Johannesburg and was particularly dedicated to education. He was born in Romford, Essex, England, the son of Dugald Sinclair of Port Elizabeth and Johannesburg. The family arrived in Port Elizabeth in 1880. According to the South African Who's Who (1908) he returned to England in 1887 'to study for his profession', being educated at Margate in England before being articled to Langham & Cole, architects & Surveyors in Ramsgate and Broadstairs, Kent, England. He returned to Johannesburg in 1896. In Johannesburg he became assistant first to PHILIP & LESLIE, then to CARTER & McINTOSH and then to JB NICHOLSON. During the Anglo-Boer War he served with the 1st Battalion Railway Pioneer Regiment for twenty-seven months and was decorated. He returned to practice in Johannesburg and married in 1903. For several years (c1902 to c1908) he was in partnership with WM PHILIP (cf PHILIP & SINCLAIR). He was Honorary Secretary to the Railway Pioneer Regiment in 1912. Sinclair was an early member of the Transvaal Institute of Architects, serving on its council for a number of years in various capacities. He was also a member of the Association of Transvaal Architects and was President of the ATA in 1920, and an enthusiastic supporter of the campaign for the registration of architects, working on the drafting of the Private Bill of the Architects' Act of 1927 and organising the sponsorship of the bill. He served on the Federal Council on Architectural Education and was a member of the Town Planning Association (Transvaal) in about 1925. Sinclair practised in Johannesburg for his whole career and was responsible for a number of well-known buildings, among which was the much admired Southern Life Building. His office was in much demand for office experience by architectural students of the University of the Witwatersrand, where his son and daughter-in-law both studied architecture and joined him in partnership until he retired in 1961. In 1959 he was practicing as DM SINCLAIR & PARTNERS.
His son CM SINCLAIR became an architect.
MSA; FRIBA 1925; Pres TPIA 1954-55. (Afr Archt Jun 1912:12 photo; Aron et al 1972; Building Sep 1929:293; Building Sep 1920:380; SAAR Mar 1925:17-22; SAAR May 1953 suppl:13 port; SAAR Jul 1963:15; SAAR Feb 1965:17ff; SAWW 1908, 1910, 1916, 1931-1932)
Publ: Standard system of measurement, Afr Archt Dec 1914:11; Johannesburg building bye-laws, Jnl ATA Jun 1916:13
Extract from SA Who's Who 1923-24. "SINCLAIR, Duncan Macdonald, F.S.A. (London), Architect and Quantity Surveyor; b. April 18th 1877, at Romford, Essex, England; s.o.l. Dugald Sinclair, of Port Elizabeth and Johannesburg. Came to South Africa 1880, returned to England 1887. Educ. at Margate, Articled to Langham & Cole, Architects, Ramsgate and Broadstairs, Kent, returned to Johannesburg 1896. Vice-President Association of Scientific and Technical Society of South Africa; Past President and Member of Council of Association of Transvaal Architects; Past President and Hony. Treasurer of Society of Architects (South. African Branch); Hony. Treasurer of Transvaal Institute of Architects; Council Member of Town Planning Association of S.A.; Hony. Secretary Trust Committee Berea Wesleyan Church. Served in 1st Battalion Railway Pioneer Regt. Anglo-Boer War, Staff Sergeant King's, and Queen's Medals, 5 bars. Add., P.O. Box 4492., 7, Saner's Buildings, Loveday and Market Streets, Johannesburg." Submitted by William MARTINSON.
All truncated references not fully cited in 'References' are those of Joanna Walker's original text and cited in full in the 'Bibliography' entry of the Lexicon.