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.