A Wellington primary is teaching children in a caravan, and other schools are using libraries as classrooms, as they try to cope with a student number's boom.
Education Ministry figures show schools in the Rongotai and Central Wellington electorates had classroom space for 14,730 children at the middle of last year and were 97 percent full - one of the highest figures in the country.
Houghton Valley School board of trustees chairperson Sarah Graydon said the school had 230 students and it was using its library as a classroom.
"We would rather have the library space as a library rather than a classroom and it's going to be exacerbated towards the middle of the year when we've got remedial work to two of the classrooms which will then have to be in the school hall."
Ms Graydon said the school was using a parent's caravan, named "Dotty", as a spill-over space for small group work, which wasn't essential, but was certainly helpful.
"The idea is to allow some space for teachers to do break-out things or have small groups with students," she said.
Berhampore School principal Mark Potter said his school was about 60 students over its 240 capacity.
He said the school was running out of places to teach children.
"We're taking out a wall here, a wall there, lose the resource room, move the library, but there's only so many rabbits we can pull out of that hat so we're running out of ideas for how to encompass this growth that we've got."
'Inward migration' boosting enrolments - principal
Wellington High School principal Nigel Hanton said the school was full, having reached a roll of 1260 students - about 350 more than it had five years ago
Mr Hanton said he was not sure where the growth had come from.
"It's probably a demographic blip in the population," he said.
"I guess we are seeing some inward migration as the city centre becomes more apartment living, families are moving from the suburbs to be close the centre of the city and I guess that's also impacting on some of our enrolments."
Mr Hanton said the school had asked the Education Ministry about its property allocation and old figures indicated it could be under-resourced by as much as four or five classrooms.
He said the growth put pressure on the school.
"Every classroom is used for every period of every day, that includes all the specialist spaces like workshops and laboratories, computer suites," he said.
"It also puts pressure on the infrastructure, there's a lot more traffic around the school and that's impacting just on the wellbeing aspect of students having enough space to relax and have their lunch."
Onslow College is outside the high-pressure areas of Rongotai and Central Wellington but its principal, Peter Leggatt, said it was also feeling the effects of enrolment growth.
"We're at absolute capacity at the moment. All our rooms are used every spell, including spaces such as our hall which are having to be used as teaching spaces given the large number we have on our roll currently," he said.
"We are as full as we can get without creating significant disruption to students' learning by inability to have them in classrooms."
Mr Leggatt said the school had 1250 students and he expected the roll would stay high for the next five years as nearby primary schools were also very full.
"This is something in central Wellington that looks as if it is going to continue for the next three, five years at least."
Rolls expected to drop - Education Ministry
Some school principals and board members told RNZ they had room for more students but Ministry of Education deputy secretary of sector enablement and support, Katrina Casey, acknowledged some schools in the Rongotai and Wellington Central electorates had reached peak rolls, which were expected to drop over the next two to three years.
However, she said some schools did need additional teaching space and the government had announced several building projects in Wellington since November 2015.
Ms Casey said some schools in the central Wellington area had a high number of out-of-zone students or no enrolment schemes at all.
"We are working with some school boards across Rongotai and Wellington Central to manage out-of-zone enrolments or to implement or amend enrolment schemes. We have also provided some roll growth classrooms and school redevelopments," she said.