[1] Fr Becheras envisaged the school as a bilingual institution from the start, emphasising instruction in both English and Chinese, a policy that continues today.

An increased enrolment saw the need for a new wing to be added to the high school compound, on the adjacent site of 51 Waterloo Street.

In 1950, the Marist Brothers took over responsibility for the administration of Catholic High; a primary section was opened in 1951, with a new school building at 8 Queen Street.

In the same year, pre-primary classes were started to prepare students for primary school Chinese study.

With continued increase in enrolment, the Queen Street buildings could not house all the students from all levels, even with double-sessions arrangements.

In March 1987, discovery of structural cracks at the Queen Street premises of the primary section caused the campus to be declared unsafe.

[7] Despite clarification later as a misjudgment, the incident prompted a decision by the Ministry of Education to relocate Catholic High School, for safety concerns in wake of the Hotel New World collapse.