The Ministry of Education is advising schools that cannot afford sprinklers to install security systems instead after two school arson attacks over the holiday weekend.
All new schools are required to have sprinkler systems installed, but the cost of retrofitting sprinklers in existing schools far exceeded cleanup costs after a fire, ministry communications advisor Steve Jones said.
"The extrapolated estimated cost for retrofitting all schools currently not sprinkled would be $500 million. This investment compares with annual fire losses averaging $3m," he said.
Kerikeri High School, in the Bay of Islands, and Mangere East School in south Auckland each lost several classrooms to deliberately lit fires over the weekend.
The schools did not have sprinkler systems, which could have significantly reduced damage, Northland Fire Service assistant national commander Trevor Andrews said.
Damage to Kerikeri High, including a spill of toxic chemicals will prevent the school's 1400 students being able to return until Thursday.
The fire highlighted the need for the Ministry of Education to rethink its policy on sprinkler systems in schools, Mr Andrews said.
It was important that all schools had them installed, he said.
Mr Jones said schools which add new buildings or put in extensions over 1000 square metres were also required to install sprinklers but ministry policy for smaller buildings was to install intruder or smoke detection systems.
About 80 percent of schools had partial or total alarm coverage, he said.
The ministry's Fire Safety and Design Requirements policy was scheduled for review later this year.
Mr Jones said while the ministry understood "the desirability" of sprinklers in schools, the cost was prohibitive.
"The ministry advises schools, where the cost of retrofitting is too expensive, to invest in security systems, such as intruder alarm systems."
