Contractors were working seven days a week to complete the build by Christmas, Ministry of Education acting head of education infrastructure services
Rob Giller said.
He said about 220 workers were on site on week days, and up to 100 at weekends.
Interior, exterior and site works, including landscaping, were proceeding simultaneously.
The project must be completed in time for the school to move from its Gorge Rd site for term 1 next year. It has an expected roll of more than 900 pupils.
Work on the 7ha site in Remarkables Park began two years ago.