In 1964, tuition fees for Grade 9 and 10 classes were removed through a five year agreement between the school board and Collège Notre Dame, Collège du Sacré-Coeur, Marymount College, and St. Charles College.
By 1967, over 10,000 students were enrolled in schools governed by the Roman Catholic Separate School Board. The board was mandated by the Ontario government to hire its own school inspectors, now referred to as superintendents. The superintendents were appointed by the board and the former St. Thomas School was renovated to serve as their administrative headquarters.
In 1968, Collège Sacré-Coeur was closed by the Jesuit priests and they agreed to sell the building to the school board. This building was leased to Cambrian College for about ten years before being transformed into a Grade 9 and 10 school for boys.