Their model identified a "climate signal" based on the per cent change between projected and past damages.
Depending on various emissions scenarios, it rose from an increase of between 7 per cent and 8 per cent in 2020 to 2040, to an increase of between 9 per cent and 25 per cent in 2080 to 2100.
For a low-emissions scenario, the expected rise in damages began to drop off toward the end of the century.
By contrast, the high-emissions scenario saw the climate signal more than double between 2020 and 2040, and 2080 and 2100.
"The increase we have projected in the public insurer's liabilities can also inform private insurers and regulators," said study co-author Professor Ilan Noy, chair in the economics of disasters at Victoria University of Wellington.
"Whether this increase necessitates a change to the amount of premiums the EQC collects annually, or in the types of risks it insures, are questions for future research and policy decisions."
New Zealand's population, and its residential building stock value, had been steadily growing over the past few decades – something that suggested future liabilities may be higher even than what the researchers predict.
The study comes in the same week the Insurance Council of New Zealand reported private insurers had spent some $118.8m last year on more than 18,000 claims over severe weather damage.
The results made 2019 the sixth most expensive year since 2010, with insurers paying more than $1.2 billion for weather related loses during the decade.
The council's chief executive, Tim Grafton, said climate change would bring an increase in the frequency of extreme weather.
"Since 2014 we have seen a significant increase in events causing damage in the hundreds of millions. The need to adapt and take steps to reduce risk is supported by wider climate research."
He pointed to IPCC figures estimated global mean sea level rise of 0.43m to 0.84m by 2100, and recent Niwa research estimating how more than 125,000 New Zealand properties were vulnerable to a metre's rise.
"This is just one of the areas of risk that New Zealand faces," Grafton said.
Big rainfall events also pack the potential to damage homes and trigger landslides and flash floods.
Five decades of annual maximum one-day rainfall has shown no clear evidence that intense events had changed since 1960 - besides some drops and increases at certain places.
But when scientists recently used another measure – and assessed all of the rain that fell across an extreme event, rather than just a day of it – and different picture emerged.
They found that, between 1961 and 2010, annual extreme rainfall when measured by event had increased noticeably in the west and south of the South Island - and had fallen in the drier north and east of both islands.
This century's five biggest storms
• February 15-16, 2004, Lower North Island storms — $148.3m
• April 3-7 2017, Cyclone Debbie —$91.5m
• November 20, 2019, Timaru hailstorm - $83.3m
• September 11-12, 2013, Nationwide storms —$77.1m
• July 10-12, 2007, Far North/Auckland/Coromandel — $72.7m
