In 1993, Trinity and nearby sister school Ruyton Girls' School introduced the Coordinate Program, whereby co-educational classes for Years 11 and 12 are conducted across the two schools. In 1996, the school purchased the Kew Municipal Offices, after the City of Kew was amalgamated into the City of Boroondara, in order to further expand its facilities. Two years later, it opened as the Peter Crawley Centre for the Arts. Peter Crawley then resigned in the same year as he accepted the position as headmaster of Knox Grammar School in Sydney. In 1999, Richard Tudor (former deputy headmaster of Melbourne Grammar School) was appointed as headmaster and the co-educational Early Learning Centre was opened.