Taxpayers have spent nearly $30 million targeting vandalism at schools in the past two years, while thieves have made off with items such as plastic guttering and wooden seats.
One Auckland school has spent close to $150,000 in emergency top-up money on repairs, while others have fenced buildings off from school grounds.
Principals say much of the vandalism - usually smashed windows, graffiti and break-ins - is difficult to prevent and wastes money that would otherwise be spent on education. Surveillance cameras, security patrols and ugly and intrusive fencing are becoming more common as schools try to reduce damage. However, such measures are costly.
Principals' Federation president Phil Harding said vandalism such as graffiti seemed to be rising, and the problem was particularly bad for low decile schools.
"It's just heartbreaking, mindless thuggery. Schools in some areas do different things, I know schools in South Auckland that lock their gate and have security on those gates in the weekend."
Figures released under the Official Information Act show schools have been allocated $22 million in vandalism grants to cover expected vandalism costs since 2012 to late last year.
Another $3 million was needed in top-up funding, when vandalism repair costs exceeded the amount budgeted.
Vandalism grant money is allocated to schools according to their risk category and roll numbers. Any grant money not spent on vandalism can be used elsewhere in the school.
South Auckland's Kia Aroha College received the most top-up funding at $148,256 since 2012, followed by Porirua College with $132,277 and Tolaga Bay Area School $95,107.
Ann Milne, principal of Kia Aroha College, a special character secondary school, said the school had an extensive network of security cameras and was fenced on three sides, with the other facing houses.
"Even with the fenced perimeter we often find the fence has been deliberately cut or damaged to provide access to the school grounds."
Ms Milne said the college's new buildings used a lot of glass, and replacing broken glass accounted for almost 70 per cent of its top-up payment in 2012.
Wesley Intermediate in Mt Roskill received $67,102 in top-up funding, much of which was spent on repairing broken windows and removing graffiti.
Principal Nigel Davis said the vandalism was frustrating and mindless, and not done by students or past students. Its extent had become hard to believe. "They used to take the copper downpipes, now they're taking the plastic downpipes. We even caught a guy unscrewing the wooden seats in the bays around the classrooms."
Mr Davis said there had been only three or four break-ins in the past two years.
"It's not people wanting to get into the school, it's more - 'I've got nothing to do, what should we do today?' It's just stupid stuff."
Wesley, which borders Lovelock Athletics Track and the May Rd War Memorial Park, was in discussions with the Ministry of Education about the installation of security cameras, or fencing.
It would cost close to $500,000 to fence the entire school perimeter.
Another option, which nearby schools had used with success, was to closely fence in the school buildings themselves. "Which means when the kids come out of the classrooms, they've got to go through a fence on to their netball courts.
"Do you put your school in lock-down and say to the community, 'You can't use it any more'? Or do you have a smaller fence, or do you try just security cameras?"
Arson frightening threat to pupils and their lessons
Arson remains a dangerous problem for schools, with one firebug causing nearly $1.4 million of damage to his former school.
As well as vandalism grants and top-up payments, the Ministry of Education has paid $2.7 million in additional funding to 37 schools that have suffered damage because of arson since 2012.
The biggest payment was $1.4 million to James Hargest College after a fire damaged six of the Invercargill school's classrooms.
A former student at the college was sentenced to three years and four months in jail on charges including arson, after the blaze engulfed classrooms in January last year.
Fires at other schools started when rubbish wheelie bins, curtains, carpet, a couch, grass and toilet paper dispensers were set on fire.
The figures were released to the Herald late last year and before another arson attack caused serious damage to classrooms at Ponsonby's Richmond Rd School.
Four classrooms were badly damaged in the fire, which started in a toilet block.
Much of the school's grass field is now occupied by relocatable classrooms.
And Pt Chevalier School has still not rebuilt an administration block that was badly burned in August, for which it received a $31,298 payment.
Two 14-year-old boys later admitted starting the fire. Principal Sandra Aitken said being targeted was upsetting, but they were ultimately lucky.
"We were fortunate that no one was hurt, and that no classrooms were affected.
"I think that's the soul-destroying thing for kids, when their work is gone, and for teachers."