Plans to reduce insulation standards for new buildings could make new houses more affordable and mean more houses are built, the building minister says.
But the Green Building Council said the move would take New Zealand back to standards that were decades out of date compared with most of the OECD. And in consultation with experts, 90 percent of those who responded wanted to keep the existing standards.
A new standard to keep homes warm and dry was introduced just last year, but Building and Construction Minister Chris Penk has confirmed he is looking at rolling it back.
Penk told Checkpoint new houses could include costs of $40,000 to $50,000 extra depending on the insulation standard they were held to. And after listening to what people wanted, he believed there should be more choice because of the need for affordable houses.
"The evidence is that construction costs have increased by 41 percent since 2019. Housing affordability is the second-worst in the OECD as I understand it. ...When people are saying - the ones who build the homes - are that there are $40,000 or even $50,000 additional costs to new builds, simply that makes housing unaffordable for many Kiwis," Penk said.
"We've heard for years and years now, that people want homes that they can actually afford to live in, and I'm going to do something about that.
"Certainly I would be an advocate for people choosing to have as much insulation as they want, but that's entirely different from saying that the government must mandate something that makes housing totally unaffordable for many young Kiwi families."
The cheaper electricity bills that came with good insulation were not as beneficial to owners' wallets as they sounded, when compared to the costs of paying off higher build costs over the lifetime of a mortgage, he said. He estimated an extra $20,000 in insulation costs would add $50,000 over the lifetime of a mortgage.
"I don't know how quickly you think you can repay a energy bill with $50,000 additional that needs to be spent, but I can tell you it's actually a hypothetical question for people who can't afford a home in the first place, because the construction costs in this country have risen so dramatically in the last few years and these are the trade-offs that are currently being made."
Cold damp houses contributing to significant health problems for New Zealand was undeniable, he said, but increasing the amount of housing stock available and getting more people housed was crucial and was about trade-offs.
"The problem with New Zealand housing stock - and the reason that there are respiratory problems and other health problems and lots of issues in fact associated with housing that isn't energy efficient - is that 50 percent of New Zealand's homes were built more than half a century ago, that's the problem," Penk said.
"It's not the ones that were build last year that need to be to a higher standard."
Penk confirmed to Checkpoint that he would be recommending some form of changes to the building standards for insulation, and while he had not decided, he was considering the standards being set back to 2022 levels: "Not the distant past".
In May, a building industry housing symposium was told that even the even with last year's upgrades, New Zealand's existing building code was already being left behind when compared to other Western countries.
Reactions to the move unpopular
On the streets of Waikato on Wednesday, people RNZ spoke to were overwhelmingly against reducing the standards, with several people describing the idea as "silly" or "stupid".
One woman said: "It is stupid. ... The last house, we had double glazing - never used to need heating, it was good. Bought a 20-year-old house ... it's freezing!"
A man said he was puzzled that resources would be spent going back on work so recently revised: "I think that would be a bad idea.
"I think the amount of years I spent renting and living in damp and mouldy homes, yeah, a lot of houses need to be improved - so I think that would be a backwards step for sure," he said.
"And undoing a lot of work that's already been done, there's other issues they can focus on, that's already been worked out - go and sort something else out, you know."
Another man said the move did not make economic sense: "New Zealand houses have been under-insulated, we're only just catching up ... [with more insulation] you save in the long run, in heating costs and in health costs."
But Penk said people may not be seeing the big picture: "The people in the vox pops perhaps are misunderstanding that we're going back to last year's standards, not the 1970s".
New Zealand's insulation standards for new builds
The effectiveness of insulation - and the standards - are measured with R-values, representing how easily heat can be lost through a material, or how energy efficient it is.
The higher the R-value, the less heat is lost, and the more insulated the building or material is; they typically fall between 0 and 7.
New houses are checked to see they meet the insulation standards when they are assessed for the building consent, and their R-value should be noted on the plans.
New Zealand's Building Code is set out in the Building Regulations 1992, and the codes for insulation are called the H1 Energy efficiency provisions.
As well as heat loss, New Zealand's insulation standards also measure the material's durability, how much protection from fire it offers, moisture transfer and accumulation, and its electrical safety.
Government agency Building Performance New Zealand said on its website that when it comes to insulation it was a case of "the more the better," and it recommend: "It's well worth spending a little extra and exceeding the minimum Building Code requirements".
New houses may need very little heating or cooling if they were designed, insulated and ventilated well, it said.
New Zealand also has separate insulation standards for rental houses.
