In his speech, Mr Ryall said he was "delighted" to open the building marking the final stage of the "long-awaited" event.
"This building ... which you have described as the heart of the school cost about $5.5million and it has been an excellent example of how a school and the Ministry of Education can work together.
"It really is is an amazing set of buildings," he said.
The new classroom building, measuring more than 60m long and 20m wide, had two levels and featured 18 classrooms.
In front of the building was a play area, sandpit and astroturf court.
The classrooms were designed as individual rooms but when doors were opened could become an open learning space.
At the opening, Mr Leckie paid tribute to the construction group Naylor Love, architect Frank Cleary of Babbage Consultants, the Ministry of Education, the school's board of trustees, school staff and students.
The celebration ended with a performance from the school's kapa haka group, followed by a morning tea.
The building was blessed on January 9 by Charles Rahiri, from the Ratana Church.