I concur with Joe, more or less.
I've heard of double glazing being done but don't think I have ever
seen any (except in Mr Boeing and Mr Airbus's fine products.
But home insulation is the norm, is well enough promoted and, as joe
says, and is government subsidised. It's mandatory in new homes.
Winter in Auckland usually gets as cold as frost plus ice on garden
ponds in some areas sometime.
It snowed lightly here in a few places in the urban areas last Winter
- something I have not seen in person in my lifetime, including this
In the South Island Winter can be substantially more severe with
occasional ones so bad that sheep and cattle die in substantial
numbers when snowed in.