A teachers union says the Government isn't doing enough to address Auckland's rapidly growing student population.
The city's schools are highly congested - just like its roads - despite the Government promising to build 41 new classrooms at eight Auckland schools.
Education minister Nikki Kaye opened two new classrooms at Henderson Valley High School in May.
Eight other schools in Auckland are now in line for new rooms too, but the New Zealand Educational Institute (NZEI) is concerned it's not enough.
"I think this needs a massive injection of funding into it to actually ensure that the needs of children are met," NZEI president Lynda Stuart says.
Of the 41 classrooms, seven will replace existing rooms but 34 will be new.
The Government says that will make room for an additional 680 students, but with a projected growth of nearly 110,000 students by 2040, Ms Stuart is concerned that'll barely touch the sides.
"I don't think it's good enough," she says.
"I think the Government really needs to be quite genuine in their commitment around moving forward."
Education Minister Nikki Kaye told Three's The Nation the Government is on track.
"We've got a lot of work of work going on behind the scenes... I'm confident we are going to be able to get there," she said.
A Ministry of Education report says 40 schools are already over capacity and another 127 are at risk of overcrowding.
Some teachers are being forced to work out of libraries or staffrooms and one school, which didn't want to be named, says its students are even being taught in prefabs without running water.
Ms Kaye says it's not a lack of investment causing problems, but schools enrolling out-of-zone students.
"I don't have enough time to cut all the ribbons across New Zealand because we invest so much into buildings."
The Government admits it is about 300 teachers short, and while it's providing funding to try and fill the gap, it says that won't mean salary increases.