One Hawke's Bay school has rot and leaks in more than half its classrooms. At least four local schools are named on a national list of leaky buildings with a repair bill expected to reach up to $1.5 billion.
The Ministry of Education is yet to finish analysing data identifying all schools, but so far 273 primary, intermediate and secondary schools nationally have been found to have a "defective" or leaking building.
In Hawke's Bay, those schools are Fairhaven School, Flaxmere College, Henry Hill School, and Kimi Ora Community School.
At Flaxmere College, 14 classrooms were found with "water ingress" - leaving just 12 unaffected, a ministry spokesman said.
Rot had been found in the damp rooms.
Principal of the school, Louise Anaru, said staff were looking on the positive side, and anticipating a better campus when repair work was completed.
"I think it is a great opportunity to provide a quality 21st century learning environment," she said. "So we are really excited about the future."
Last June, a national defective-building survey resulted in 1647 schools having to be checked for leaks, with an estimated repair bill of $1.1 billion for the 245 schools found to have a leaky building. The latest report says this number has now risen by 28 schools.
March estimates put the price closer to $1.5 billion, a ministry document entitled "Rejuvenation of Schools' Infrastructure Proposal" reported.
"It is estimated likely to cost between $1 billion and $1.5 billion to repair or replace defective buildings modified between 1995 and 2005 which have weather-tightness issues."
The rest of the report - a 16-page document - is blacked out.
The bill for Hawke's Bay schools had not been tallied yet, the ministry spokesman said.
"All affected blocks at the above schools are in the very early stages of the remediation process," he said. "Cost estimates have not been provided as yet."
Due to the early stages, the cause of problems and extent of local repair work was also unknown, but could include re-roofing and repairs to the cladding.
"In general, weather-tightness defects can be attributed to a number of different causes, such as design defects, poor construction, maintenance and sometimes minimal ground clearances."
The general manager of the schools property infrastructure group, Kim Shannon, said the ministry was representing 24 of the schools with leaky buildings nationally in legal action against construction and architecture firms in a bid to win compensation for the repair work.