James Birrell commenced his own practice in 1966 after resigning from his position as Architect with the University of Queensland. At this time he also acquired the firm of Scorer and Scorer, which formed the basis of his first jobs. One of those jobs was the Agrictulture and Entomology Buidling at University of Queensland a Scorer and Scorer commission from the Co-ordinator General of the Queensland Government's Department of Works. James Birrell & Partners had offices at various times in Brisbane, Townsville, Port Moresby, and Maroochydore with various partners (including Lorant Kulley, Philip Conn, Richard Stringer and Lindsay Mack). Birrell wound the business up in 1997.

James Peter Birrell was born in Melbourne on the 24 October 1928. He was educated at the Melbourne Technical College (1945-1949) while working for the Victorian State Works Department (1947), for R.G. Warren (1948) and the Commonwealth Works Department (1948-1950). He transferred into a fourth year course in the School of Architecture at the University of Melbourne. Following his graduation in 1950, he returned to the Commonwealth Works Department and worked for them in Melbourne, Canberra and Darwin. He was appointed Architect in charge of the Architectural Branch in the Brisbane City Council (1955-1961). He resigned to become Staff Architect to the University of Queensland (1961-1966). He commenced his own practice in 1966, with offices at various times in Brisbane, Townsville, Port Moresby, and Maroochydore with various partners (including Lorant Kulley, Philip Conn, Richard Stringer and Lindsay Mack). He died on 20 September 2019, aged 90.