This Karl Langer collection contains architectural drawings, financial records, correspondence, biographical and personal notes, articles, speeches, job photos, subject files, diaries, journal and newspaper cuttings relating to the works, life and interests of Karl Langer. Buildings where Karl Langer was the architect are represented in this collection. Drawings and files include those realting to: St. Peters Lutheran College, Brisbane; Ipswich Girls Grammar School; Ipswich Boys Grammar School; Lennons Hotel, Brisbane and Lennons Hotel, Broadbeach. Karl Langer taught at the University of Queensland and Queensland University of Technology and there are related documents to this time. Plans and photographs of the Langer House, designed by Karl Langer are included in the collection. The Langer House was added to the Queensland Heritage Register on 21 October 1992.

This collection is comprised three series. There is material associated with or acquired during the finalising of the estate of Gertrude Langer, which John Riedel assisted with. It includes a 1939 diary from Gertrude Langer, correspondence relating to the Langer's, eulogies and notes about Gertrude Langer, a copy of her will, newspaper cuttings, and photographs.

The second series contains papers and correspondence associated with John Riedel and the Langer Memorial Committee.

The final series is comprised of three photographs of Kathleen Campbell Brown, and some newspaper cuttings relating to her.

Correspondence and documents relating to UQ School of Architecture curriculum, research on Karl Langer and architectural conservation.

Architectural plans and drawings.