How to Upgrade Your Thermal Envelope Above the Building Code
Some good advice here – we agree you should invest as much as you can to upgrade the thermal envelope of your new-build. Put in as much insulation as you can, and invest in the best windows you can afford.
When you’re designing a new home, or getting one built, you should invest as much as you can to upgrade the thermal envelope. Put in as much insulation as you can, and invest in the best windows you can afford.
Here’s a walk through the minimum requirements of the New Zealand building code in relation to insulation, and recommend how to go beyond this bare minimum.
The Building Code is not a Target – The building code is not a target. It represents the worst house you’re legally allowed to build.
The New Zealand Building Code defines three climate zones, but for the sake of insulation, there are really only two distinctions as zones 1 and 2 get lumped together. For a standard timber or steel framed house, you need at least:
R 2.9 or 3.3 in the ceiling (North Island and South Island respectively)
R 1.0 or 2.0 in the walls (North Island South Island respectively)
R 1.3 in the floor (1.9 for a ‘heated’ floor)
R 0.26 windows
A solid construction house (for example solid timber walls or solid concrete), can get away with even less, according to the code.
Do it Once. Do it Right.
Insulation and windows are not something you’re going to want to have to replace or upgrade. I know they’re not the sexiest part of a new home, but they are the fundamentals of what will ensure a comfortable, healthy home. I always suggest to clients that they consider saving on other aspects of their home that can be easily upgraded later down the track and put as much of your budget as possible towards the best quality envelop you can possibly afford.