In August 2005 the fifty years old Jubilee Halls in Calgary and Edmonton were reopened after a major renovation project. In 1955 the two almost identical halls were built in commemoration of the first fifty years of the province Alberta, Canada. Although the halls were built according to the best acoustical knowledge of that time, it had become clear that the halls suffered by several acoustical problems, and thus the government of Alberta wanted the halls to be brought up-to-date for the 100 years jubilee of the state. The Canadian architect Fred Valentine together with other North American consultants and the Danish acoustical company JORDAN AKUSTIK were chosen for the renovation project. In this remodelling project the ODEON room acoustic modelling program turned out to be a very efficient tool. The various proposals for changes in the auditorium were analysed and compared to each other and to the original conditions in grid calculations covering all seats in the auditorium. The final design was also presented at auralization sessions. The paper presents the major steps in the design process, starting by the identification of the acoustical problems, and the final results that have been achieved in the new halls.