Revealed: Green homeowners could save up to $98,000 on their mortgage bill

- Investing 0.5% to 1% more in a Homestar home can save homeowners tens of thousands long-term.

- Homeowners can save up to $98,000 over a 30-year loan through discounted mortgages and energy savings.

- Only 13% of new homes were Homestar certified in 2020, but awareness of benefits is growing.

Buying a "green" home could save Kiwis tens of thousands of dollars in the long run, new research suggests.

A report released today by Infometrics found that Homestar-rated properties outperformed others in the market, despite costing 0.5% to 1% more to build.

Economist Brad Olsen, Infometric's CEO, told OneRoof that the research should give Kiwis pause when weighing up what kind of property to buy, even in the current economic climate.

“There’s a financial advantage, there’s an environmental advantage - a bit of a housing match made in heaven," he said.

Infometrics CEO Brad Olsen said green homes were "good for people’s wallets and good for the planet”. Photo / Mark Mitchell

Homestar-rated properties, which are certified by the New Zealand Green Building Council, are designed to be healthier, warmer and drier, as well as more energy efficient.

The Infometrics analysis found that buyers opting for a Homestar-rated home could access discounted mortgage rates such as ANZ’s Healthy Home Loan package. These are typically 0.25% lower than the special rate and could save holders $40,000 over a typical 30-year loan.

The savings to the electricity bill weren’t quite as big and could add up to an average of $435 a year for a standalone home, but were still worth having, Olsen said. However, the rising cost of electricity meant that these savings could be between $580 and $900 a year by 2050.

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The total savings in both interest and power ranged from $62,800 for a terraced house in Auckland to $98,000 for a standalone house in Wellington over the life of a loan.

“It’s not often that we do this analysis, and it becomes very clear very quickly that this is definitely worth doing,” Olsen told OneRoof.

“Although a Homestar house costs you more up front, you repay that [difference] within a couple of years, and you actually make money compared to another house over the lifetime of your ownership and paying down your mortgage,” he said.

Only 13% or 5000 new dwellings consented in 2020 were Homestar certified. Olsen said this might be because not many people realised there were cheaper loans available for greener homes.

NZGBC chief Andrew Eagles said the research torpedoed assumptions that building healthier homes was more expensive. Photo / Supplied

Olsen said ANZ was the only bank offering mortgage discounts for green homes, but he felt other banks would get on board because it was “good for people’s wallets and good for the planet”.

“The banks will look at it and go, 'Look, we keep wanting to walk a stronger walk on sustainability and this is how we can do it.”

New Zealand Green Building Council chief executive Andrew Eagles said there was a common misconception that building healthier, more sustainable homes was more expensive.

“This report confirms what we’ve long known; building better homes is a win for healthier New Zealanders, the planet, and are clearly more affordable in the long run,” he said.

“The research shows you can be $60,000 better off through your mortgage - effectively giving you two years less on your mortgage. And you get a healthier place, and you get lower bills.”

Eagles said there were also significant benefits to builders and developers building to Homestar certification because a lot of the major banks had started offering lower interest development finance on greener buildings.

“That can save them huge amounts.”

Eagles said people had finally started to lean into the benefits of electric vehicles, and he believed that over time the same would happen when it came to housing. “People will just say, 'I’m not going back to a building code house, I want quality for my family.'”

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* OneRoof is a sponsor of the NZGBC Housing Summit 2025