The number of hospital buildings that are earthquake-prone is rising as new assessments come in, reversing a downward trend.
Newly released information shows there are 77 such buildings that have staff or patients in them, up from 64 a year ago.
Once unoccupied buildings are included, the total hits 110, up from 103 a year ago.
Tougher earthquake risk assessment rules since 2017 along with stricter health and safety laws that increase employer liability for injury or death to workers, are forcing district health boards to do new seismic checks on buildings.
Even so, some DHBs have not looked at all their seismically suspect buildings.
Counties Manukau DHB, for instance, has fully assessed one, but has at least six assessments still to go on seismically-suspect buildings, including major ward blocks.
A letter Counties Manukau DHB wrote to the ministry about a new risk assessment shows it will lose its entire main x-ray department and 90 patient beds if it has to evacuate its one proven earthquake-prone site, the Galbraith building.
"While we appreciate that Galbraith may not be regarded as the most urgent case given the low seismic risk of the Auckland region ... the life safety risk consequences are extreme," acting chief executive Gloria Johnson said.
South Auckland is in the lowest of the three quake-risk zones; but Canterbury and the West Coast are in the medium-risk zone and have the two largest numbers of quake-prone buildings, 36 and 17 respectively; Wellington, in the shakiest zone, has the fourth highest number (nine); Waikato is third, with 13, down two since 2017.
Hutt Valley DHB reports having no quake-prone buildings. However, engineers recently found it has poor non-structural restraints in some older buildings and dangerously heavy ceiling tiles, which it has been replacing.
This points to the many gaps of what's known about quake risks at some of the other 20 DHBs.
"We asked DHBs to provide additional information on non-structural seismic restraints. Five DHBs did not provide a response in time," a ministry report from January 2018 released to RNZ under the Official Information Act said.
"Two DHBs planned to review non-structural restraints during refurbishment programmes only."
The 13 other DHBs were checking or fixing deficient restraints, it said.
Non-structural restraints are not even covered by the usual seismic structural assessments done by engineers, even though it was just such failures that crippled hospital services in the 2011 Christchurch quake.
The Health Ministry did not start properly counting hospital quake-prone buildings until 2013, two years after that disaster.
Since then, numbers had dropped by about a third - or 50 - hitting 104 occupied and unoccupied buildings early this year, before creeping back up to at least 110 after the Canterbury DHB got its new assessments back.
It faces the biggest job, with 22 of its 36 quake-prone buildings still occupied.
"It is our approach that we don't wait for a building to be formally placed on a register before we start to implement necessary plans and controls, as evidenced with our work on Parkside [medical blocks] to date," the DHB said in a statement.
New construction in Christchurch and at the West Coast DHB is expected eventually to bring quake-prone numbers down, although the work is facing long delays and cost rises.
The Health Ministry said the DHBs were prioritising work on any buildings that would be needed in an emergency; and prioritising fixing buildings "based on funding pressures".
At Counties Manukau, that means it is grappling with the choice of spending $75 million at least on bringing the quake-prone Galbraith building up to just the minimum 35 percent of standard, while at the same time putting extra patient beds into Galbraith this winter and, as recently as last year, debating whether to reopen operating theatres in it.
While the true number of quake-prone hospital buildings in New Zealand is unclear, it's also not known what it would cost to fix or replace them all.
"All DHB CEOs are asked to provide an assurance that they are taking all reasonable and appropriate steps to identify and manage the seismic risk," the ministry said in its briefing to the Health Minister in January.
"All CEOs apart from ... Tairawhiti DHB has provided this assurance."
Tairawhiti has two quake-prone buildings, one of them occupied. Its chief executive, Jim Green, said he had now provided the assurance the ministry wanted, after having talks with it following the revelations in March about Middlemore Hospital's building problems.