Six buildings at Alfriston College in south Auckland, including five classroom blocks and an administration block, have been deemed quake-prone. Photo: Supplied
More than a third of the country's 27 quake-prone school buildings were built in the past 20 years and include almost an entire Auckland secondary school.
The Education Ministry told RNZ six of the 10 recently constructed buildings were at Alfriston College, which opened in 2004.
The remaining four were at Burnside High School's J Block, Taihape Area School's Block A, a gym at Wellington's Taita College, and the Pipitea Block at Wellington Girls' College.
A third of NZ's quake prone school buildings built in past 20 years
The poor ratings were "due to design and construction issues, as well as an improved understanding of their method of construction over the last decade", the ministry said.
The six buildings at Alfriston included five classroom blocks and a block containing its administration, technology rooms, and library.
They were assessed at 21-25 percent of the New Building Standards.
Buildings below 34 percent are considered quake-prone.
- Read more: The Detail: Quake rules in for a shake-up
"The building rating is a result of a combination of both design and construction issues, as well as an improved understanding over the last decade of mesh reinforcing commonly used in this era of construction," the ministry said.
The Alfriston College buildings would be strengthened, but the cost of the work was yet to be decided.
A design had been completed for one of the buildings and design work had begun for the remaining five, the ministry said.
The list also included Taihape Area School's main block, which had problems with weather-tightness after opening in 2009.
It was assessed as meeting just 15 percent of the NBS and would be demolished and replaced.
The ministry said the list might grow further as initial assessments showed a further 10 buildings were quake-prone, but the assessments were under review.
Two classroom blocks at Christchurch's Burnside High School were closed in March after they were deemed at risk in a quake. Photo: Google Maps
The list of 27 confirmed quake-prone school buildings included a tower block at Whanganui City College rated at 25 percent of the NBS, and two large classroom blocks at Burnside High School in Christchurch, which were closed in March after they were assessed at 15 percent.
Burnside principal Scott Haines told RNZ the the Education Ministry was considering whether to remediate or demolish and replace the two buildings.
The school's preference was for the latter, he said.
"The rebuild option is marginally more expensive, but that would generate new buildings with a new 50-year lifespan, rather than remediating buildings that are already 24 years old, essentially half-way through their useful life."
Burnside High had commissioned seismic assessments of two other buildings built around the same time and designed by the same firm as the quake-prone classroom blocks.
The school would have major problems if those buildings were also found to be quake-prone and it was already considering how it would cope.
"It would be a significant logistical challenge for us," he said.