24 January 2023
If you're hot inside when the summer sun is directly overhead - you probably need more insulation.
Home insulation not only keeps heat inside during winter - it keeps heat out in summer.
The temperatures in your roof space can escalate to over 40 degrees in summer. Ceiling insulation creates a thermal barrier to prevent that heat transferring through the ceiling into your home. Even when the summer sun is directly overhead, with sufficient insulation you should still be comfortable inside.
Many homes have only insulated to the minimum level required under the New Zealand Building Code and recently the code for ceilings in new homes increased substantially to R6.0.
6 ways to help keep your home cool in summer
- Increase your ceiling insulation to reduce heat transfer from the roof.
- Close curtains to prevent direct sunlight pouring into your home especially in mid-late afternoon.
- Open windows and doors to allow a fresh cross-breeze through your home.
- BBQ instead of oven roasting to avoid an extra heat source inside your home.
- Plant deciduous trees for summer shade without blocking the winter sun.
- Consider an energy efficient heat pump for those days/nights of extreme heat - it'll keep you warmed in winter too.
Summer Insulation Case Study
Rosie's home was built in 1999 when she didn't know much about ceiling insulation and had so many other choices to make with the new home that she was happy to leave the insulation selection to the builder. In the ceiling they used a loose-fill fibreglass product.
Years later, educated by EECA advertising she had a look and discovered that the loose fluff insulation had not only settled - there was also so little that it had blown to the corners in many sections and definitely wasn't up to much.
Rosie said "In deciding to upgrade my insulation I chose to install more than the minimum required under the building code. I'd learnt my lesson and wanted to be warm in winter." So for Rosie's Auckland home where a minimum of R 2.9 insulation was required, we installed R3.6 Mammoth ceiling blanket which is the amount we'd normally install in the South Island.
To Rosie's surprise, working from home over summer, she now discovers her home is also a comfortable temperature in the height of summer till mid-afternoon when the sun streams into her north-west facing windows. "Then I just pull the thermal curtains to keep the direct sun out. It's great to have a cool refuge inside especially while I'm working."