Chris Hipkins announced the projects during a visit to Waimea College in Nelson today.
It's part of the $164 million package announced yesterday.
"More and more families are choosing to move to Rolleston post the earthquakes. It's one of the fastest growing areas in the country.
"Five million will also be used to fund short-term classrooms at schools in the South Island facing severe pressure from rapid roll growth," Hipkins said.
The funding will go towards a total of 28 classrooms in schools in Canterbury, Otago, Nelson and Tasman, with a total of 616 student places.
The other $7m will deliver permanent roll growth classrooms at Waimea College, St Martins School in Christchurch, Prebbleton School, and Grants Braes School in Dunedin.
"Families rightly expect their children to be able to learn in warm, dry and comfortable classrooms, and we are working hard to make that happen as a major contributor to New Zealand being the best country in the world to bring up a child," Hipkins said.
He added that the spending would also provide a pipeline of work for the construction industry and other businesses.