There are fresh warnings the wet climate is creating the perfect conditions for outbreaks of mould.
One Auckland removal business has recorded a 30 percent increase in customers since the city's floods earlier this year.
Scraping thick coats of mould off ceilings is keeping mould removal business Restoration Specialists busier than ever.
"We've seen some real horrible ones where we wonder how people can be living in that environment," said Restoration Specialists director Tom Law.
Law said the aftermath of Auckland's floods has seen the number of desperate families skyrocket.
"We stopped all digital marketing after the floods for about a period of two months - and during that period we still saw an increase of about 30 percent," he said.
And it's not just the frequency of call-outs increasing - each mould contamination is noticeably worse.
"The coverage seems to be a lot more dense - we are seeing it in places we haven't seen it before, underneath properties," he said.
"Our nurses are going into homes now and they can literally write their names with their fingers on walls, the wall is that thick," Asthma NZ CEO Katheren Leitner said.
And with wetter weather countrywide, Leitner said the impact on people's health is catastrophic.
"We're seeing an increase in the number of people being diagnosed with an onset of asthma... they're waking up with a rattle on their chest," she said.
"A lot of the parents are beside themselves trying to get rid of it."
Otago University senior research fellow Caroline Halley said with climate change well and truly here, improving construction methods has never been more important.
"The climate has certainly thrown a lot of weather events at us, with rivers in the sky bringing a lot more moisture in our homes," she said.
"We really need to get better and smarter at building warmer dryer homes, and that's an improvement on our building code."
And with all eyes on the building codes there's mounting pressure to clean up the way our homes are built in the first place.
"While the building conditions are getting better, we are still seeing mould conditions even in newer homes as well," Law said.
