"The main fire is extinguished and [crew] are going through cleaning all the hotspots out," a spokesman said last night.
At the site early this morning, NewstalkZB reporter Joey Dwyer said tape had been put up around the burnt building and a couple of passersby were trying to look in.
Aucklanders from the North Shore and western suburbs could see smoke billowing across the city after the fire broke out on Tuesday afternoon.
The fire was in the school's tech dome, which is where art and textiles classes are held.