Records of the Cardiff Bay Opera House Trust (and its predecessor Opera House Steering Committee), mainly committee and publicity material, 1991-1997; papers relating to the architects competition, 1994-1996; proposed Opera House building design and surveyors' correspondence, 1994-1995; administrative correspondence, 1994-1996; funding applications, 1995-1996; financial papers, 1993-1995; and public relations (press cuttings), 1994-1996.

Papers of Richard Emrys Bonsall, mainly architectural papers relating to buildings in the Aberystwyth area, Cardiganshire, 1930-1964, including notebook with architectural notes, [c. 1930]-1935; diary of Hywel Owen Jones, 1930-1933; contract certificate counterfoils, 1938-1963; building specifications, 1946-1964; papers relating to alterations to the Wynnstay Arms Hotel, Oswestry and the Royal Hotel, Llangollen, 1955-1964; and copy letters from him, 1959-1961.