19/10/2026
"You can't touch the door - it burns your hand."
That’s the reality for Jared Laidlaw in this RNZ article, and in plenty of other NZ homes, on a normal summer day. Not a fault, not a failure, just a normal house doing what NZ homes increasingly do: overheat. And the real problem is that we’ve started treating it as normal.
Overheating has climbed the list of homeowner complaints over the last few summers and with spring temperatures rising, it’s now back on the public radar.
You feel it most at night with bedrooms that don’t cool down, kids who won’t settle, older family members who struggle in the heat. It’s not a comfort nitpick. Poor sleep and sustained heat load are a genuine health issue, and infants and the elderly carry the most risk.
So, you’d expect this to be a priority. It isn’t. MBIE has announced overheating won’t be part of a Building Code review until 2031.
Here at Ambiance, we agree with Andrew Eagles of the New Zealand Green Building Council that a five-year wait is too long.
That’s 5 more years of homes being built that don’t account for heat. Over the last 5 years 99,561 residential building consents have been issued in New Zealand, so we’re talking about thousands more house designs being locked in before any new requirements are even considered, let alone implemented.
The annoying bit is we already have the building science to prevent homes getting too hot. Overheating is a whole-building problem with insulation, ventilation, airtightness, thermal bridging and windows working together, and we already know how to get each one right.
Windows are where it bites hardest, and it’s where New Zealand has quietly been going backwards. Aluminium has dominated this market here since the 1970s. It has its strengths, but aluminium conducts heat readily, so the frames allow the heat outside to come straight into the room.
uPVC works the opposite way. It has naturally low thermal conductivity, so the frame resists heat transfer instead. In practice that means a home that stays comfortable without the aircon working overtime. It’s the same reason uPVC has been the default across hot European climates for decades.
As an industry, we don’t have to wait until 2031 to start making smarter choices that prevent overheating. If you’re designing or building and want to get ahead of the heat problem rather than inherit it, talk to us.
Find the full RNZ article here: https://ap1.hubs.ly/H01r_B30
