Following a limited competition, the Sydney architectural firm Bunning Madden (B) in association with Tom O'Mahony were chosen in 1961 to design the National Library of Australia building on the shores of Lake Burley Griffin. The principal architect, Walter Bunning, came up with a design for a large central building flanked by two smaller buildings to be constructed over a 40 year period. The first stage of the library, the central wing, was opened in 1968. During the next few years, the lower ground floors were completed. In 1979 the firm was contracted to carry out an extension of the podium on the lake side of the building. After a contracted dispute with trade unions in 1983, it was decided that the asbestos in the library's roof should be removed. Progress on the library podium extension was also troubled by a major fire in 1985. In 1988 B's formal association with the library ended.