Personal papers, correspondence, manuscripts, diaries, notes, photos, slides, taped lectures (C.L.F.), maps, plans, pamphlets, newspaper clippings and miscellaneous publications, as well as a stamp collection.

Architectural drawings of residential and commercial buildings, job files, incoming and outgoing correspondence, photographs and research material for his book on Walter Burley Griffin. Includes plans by Scorer and Scorer which Birrell obtained when he purchased the firm in 1966. The architectural drawings in this collection include those from his student days, his time with the Commonwealth Department of Works, the Brisbane City Council, the University of Queensland (as University Architect), and his private practices. Drawings for buildings not constructed are also in this collection.

The Geology Annex was submitted with the proposals for the Chemistry Annex and the Western Arts Building to the Australian Universities Commission (A.U.C.) in 1965, and rejected. It was to be situated behind the exiting Geology building, along Circular Drive (now named Staff House Road) between the Physics Annex and the bookshop. It was designed with basement, ground and first to fifth floors. It was resubmitted to the A.U.C. in 1966 and rejected again. This file comprises 16 plans for the proposed geology annex, including pilot plans, elevation, perspective views, floor plans for each level, as well a master planning conception drawing, massing considerations drawing and sketches of Geology annex view from Lake, the North East and from within the court (or intimate space as referred to on one of the concept drawings). One pilot plan dated March 1965.

The Western Arts Building was designed to be geometrically related to the existing surrounding buildings forming a visual relation across Mill Road. It was to sit back from the western end of Main Building (Forgan Smith), linked by a cloister. The pilot plan for the proposed Western Arts Building designed by Birrell was submitted to the Australian Universities Commission (A.U.C.) in 1965 and rejected. Birrell's design was a break from the original design by Hennessy and Hennessy who were eventually commissioned as architects for the Western Arts building (Mitchie Building) on 16 March 1967.

This file consists of 35 plans for proposed New Western Arts building on the St. Lucia campus. Includes: site plans and presentation sketches for floor plans and perspectives.