It is not only first home-buyers who are casting a nervous eye at rapidly climbing property prices.

Sites in Auckland and possibly Queenstown could be land-banked for up to 30 years for schools.

The Ministry of Education must find space for 107,000 more school children in Auckland alone by 2040 and planned housing intensification means pressure will be felt within existing city limits.

Population growth areas in Auckland include Warkworth, Wainui, Silverdale, Albany, Long Bay, Kumeu, Whenuapai, Scott Point, Massey, Flatbush, Takanini, Clevedon, Drury, Pukekohe and Pokeno.


And in Auckland's inner-city, apartment-dwellers are predicted to increase to 78,000 in 2040.

"Short term lead-in for land acquisition means in areas of growth and land scarcity, the ministry can have great difficulty locating suitable sites for new schools," a ministry document notes.

"New school-site acquisitions normally have a lead-in of three to five years."

Associate Education Minister Nikki Kaye told the Herald on Sunday that in some areas it made sense to look at buying land that wouldn't be needed for 20-30 years.

Land could be leased out until required for schooling, or sold if plans changed.

Labour's education spokesman Chris Hipkins agreed with a longer-term approach, but he said the Government had so far done the opposite.

"Governments in the past have thought much further into the future and purchased land on the basis that it may be needed for future growth, and Nikki Kaye and the current National Government sold a whole lot of it over the last couple years.

"Some of it was purchased as far back as the 1980s."

When considering buying land, another change will be to consider Year 1-13 campuses and "communities of schools", in which groups of schools are given extra funding to work together.

The Public Works Act allows land to be compulsorily acquired for education purposes.

Asked if that power could be used in the future, Kaye said it was possible but would be a last resort.

Other measures to cope with roll growth include shifting enrolment zones, adding primary children to intermediate schools and using multi-storey classroom blocks.

New schools are not always welcomed. The ministry paid $7.5 million to the Auckland Trotting Club for more than 3ha of Epsom land in 1999 for a 1500-student school.

The school never eventuated after fierce opposition by residents who wanted to stay in-zone for existing schools.

An analysis of roll information shows between 2003 and 2014, Auckland's Westmere School grew by 52 per cent, and nearby Western Springs College almost doubled in size.

However, at many schools, particularly low-decile schools, numbers have fallen.

Because a certain amount of funding is pegged to student numbers, schools can be in competition with each other, and try to attract some students from out of the local area.