The new Scott Pt school was due to open in 2021, Hipkins said.
Potential upgrades for existing schools would be announced in the next few months.
Hipkins said both new builds and upgrades of schools were equally important, but it was dependent on funding and capacity within the building industry. Schools in the worst conditions would be focused on first.
"I want to make this as easy as possible so schools are there to actually do what they need to do."
Hipkins made the announcement today at Waterview School, situated in the central Auckland suburb of Waterview. The school caters for children in Years 1 to 6, and has a roll of 305 children.
The new purpose-built school opened in February 2017.
Now a further $6.3m has been earmarked for expansion to take an extra 240 children.
"We know that Waterview Primary School is already struggling with its current facilities in terms of the demand for places here and we want to get ahead of that and are setting aside funding," Hipkins said.
Paerata and Waterview schools had been targeted for expansion based on where the population pressure was, or where demand was likely to grow.
"Here at Waterview we know that there is a lot of subdivision development going on and there is going to be more of that, particularly with things like the Unitec development," Hipkins said.
"We are trying to get ahead of the demand so that the capacity is there, rather than schools becoming overcrowded as the population continues to grow."
Hipkins acknowledged that schools outside Auckland would also require extra space.
Today's announcement comes after the Government announced earlier this year that it would build 4000 new homes in the area under the KiwiBuild programme.
The development will take place on 29ha of Unitec land in the suburb of Mt Albert and hold a mix of affordable KiwiBuild homes for first-home buyers and open housing.
At the time current schools in the area spoke of the possibility of the addition of a new school to cater for the population growth.
Avondale Intermediate principal Jo Hardwidge said it could be difficult for construction to happen as quickly as it needs to.
According to projection plans put to Avondale Intermediate by the ministry the roll could shoot up from its current 315 to about 900 in the next six or seven years.
Prime Minister Jacinda Ardern earlier said she wasn't sure if there was capacity for a "mega-school" in the area.