New homes overheating: What has happened two years after problems flagged?

Last January, the Herald reported how some Auckland terraced and apartment homes were overheating, causing distress and potential health issues for inhabitants.

In Christchurch in his new home, Rood told the Herald this week he’s glad to be in another place where the bedroom doesn’t get to the 57.1C he once measured.

Danny Rood of Christchurch complained about living in a hot house in 2024. He has since moved twice and now lives in a cooler place. Photo / Danny Rood

But home owner and landlord Jenny Stewart said there was nothing wrong with the home he rented if it was managed correctly.

She lives in Queenstown, and other tenants now rent the place without problems, she said.

No one had asked her opinion at the time Rood raised issues, Stewart said.

Overheating in apartments and townhouses is a big problem. Minister Chris Penk has vowed to solve it. Photo / Brett Phibbs

Rood told the Herald this month that back in 2024, he had used a Briscoes-bought room-temperature thermometer; he measured a high of 57.1C in his upstairs bedroom.

The two-level home’s north-facing front was covered in double-glazing. There was no shade.

His bedroom was upstairs beneath a skillion roof, meaning it had little air gap and was not a pitched roof.

Overheating in new homes – a problem raised by the Green Building Council. Photo / 123rf

The roof was black, he said, attracting and retaining heat. Going to bed was “hell” at the Seddon St house.

He is now renting a single-level home built around 2018 or 2019 with a pitched roof and shade from other homes nearby. It does not have a north-facing wall of double-glazing either, he said.

Stewart denied overheating problems at her house and said it met healthy homes regulations. If blackout blinds were used upstairs in bedrooms, along with windows opened, and a fan run, bedrooms could be kept cool, she said.

Auckland apartments: north-facing windows are cited as one of the reasons for overheating. Photo / Brett Phibbs

Rood said he had tried all he could but only a heat pump installed in the bedroom would have resolved matters. Downstairs, the tenants could turn the air conditioning on, he said.

But that cool air did not travel upstairs.

He was supplied with a fan with an ice pack while in the hot house but that just moved the hot air around, he said.

“It’s like putting a glass of cold water into an oven,” Rood said.

Andrew Eagles of the Green Building Council. Photo / Andrew Eagles

Eagles said another summer was passing with no action from the Government to reform regulations which would stop hot houses from being designed and built.

Every month of inaction sees more and more homes being built – at least half of them terraced or apartments, he said.

“That’s many thousands of families suffering from overheating.”

In November the Green Building Council and Auckland Council called for Penk to take steps to address the problem.

Building and Construction Minister Chris Penk. Photo / Mark Mitchell

Eagles said many recently built homes had unacceptably high indoor temperatures during summer.

The absence of a check at the design stage was a key contributing factor, he complained.

International building codes, including those in Australia and the UK, require checking at the design stage and a limit on internal heat gain.

Unfortunately, the New Zealand Building Code had no such requirement, Eagles said.

Large windows, a lack of eaves or other shade, no consideration of a property’s direction towards the sun and poor ventilation were causing overheating in old and new builds, he said.

An Auckland Council study of medium-density homes found highly glazed upstairs bedrooms with tight window safety latches in new terraces and apartments are sweltering, resulting in uncomfortable sleeping conditions.

Chris Penk is vowing action. Photo / RNZ, Nick Monro

“Upper levels of terraced houses and duplexes are too hot in summer,” the report, Life in Medium Density Housing in Tāmaki Makaurau/Auckland, by Kathryn Ovenden and Melanie McKelvie who work in policy, planning and governance, says.

Penk said: “It is surprising and disappointing in equal measure that the Building Code that I inherited was so deficient in matters of ventilation.

“Insulation is hugely important, as is ventilation. It is a shame that one of these has been neglected until now.

“I’m determined that we rectify this situation. An upcoming review of the Building Code will include a strong focus on preventing the overheating of multi-storey dwellings such as townhouses.”

The Ministry of Business, Innovation and Employment was looking at the ventilation issue.

Anne Gibson has been the Herald‘s property editor for 25 years, written books and covered property extensively here and overseas.

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