From late 1969 Hoyts and the trustees of the Mayne Estate began devising proposals to redevelop the Regent Theatre. The manager of Hoyts Queensland revealed these plans in The Courier-Mail in January 1973 which prompted the National Trust of Queensland to investigate the historic value of the theatre and include it on the organisation's heritage list from July 1974. In view of the looming date of 1977, when the lease granted to Hoyts over the Mayne estate land would expire, it was decided that the best option for the continued generation of income was to replace the existing theatre with a number of smaller cinemas. The local architectural firm commissioned by the trustees to complete the design for this proposal was Lange L Powell, Dods and Thorpe. The National Trust made an objection to a preliminary application lodged with the Brisbane City Council and succeeded in postponing the project. In the meantime the organisation presented alternative plans, which were eventually deemed economically unviable. A final application was approved by the Brisbane City Council in June 1978 for a scheme that retained the entrance hall and grand foyer, cafe and offices but replaced the auditorium with four cinemas and a shopping arcade. An active local "Save the Regent" campaign began the following month, just after the National Heritage Commission announced that the theatre would be included on its National Register.