What’s causing New Builds to overheat?
Here are five key reasons some New Builds are getting too hot:
#1 - We have an airtight building code
The building code has got tighter. It means you need more insulation and properties are more airtight.
That’s good in winter, but in summer it can backfire.
Older homes often have gaps and drafts that let air flow through, but modern builds are sealed tight and all that heat gets stuck inside.
If a home doesn’t have proper ventilation, airflow, or cooling systems, it can become uncomfortably hot. Fast.
#2 - Our properties are north-facing with large windows
Kiwis often like north-facing homes. That’s typically a selling point. It means more sun and light.
But if you also have floor-to-ceiling windows with no shade, it can trap heat like a greenhouse.
#3 - Windows don’t always fully open
These days builders often add security catches on windows. They’re a great idea – until you realise you can’t open them far enough to let cool air in.
This is common in tall, three-storey townhouses or apartments.
Sometimes it’s about safety (especially for children) but it also means you can’t get enough fresh air into the room to cool it down.
#4 - There aren’t enough mature trees to provide shade
Older properties tend to have mature trees that shade houses. New developments? Not so much.
Developers often clear the site, then replant baby trees, and those baby trees don’t offer much shade for the first few years.
#5 - Newer houses don’t have eaves
Eaves (those overhanging bits of the roof) shade your house. They keep direct sunlight off your windows. Some modern townhouses skip them to save space or cut costs.
No eaves = more sun on windows = more heat inside.
