I think that most of us would agree that the standard of heating and insulation isn't what we are used to from other parts of the world, and no Diny I wouldnt 'snap at anybodies ankles' for saying that. All I said last time was that you were lucky that you didn't have to put up with it. Its obviously quite an issue with you.
Its not that the houses are timber/tin thats the problem as any one who has lived in a timber house in North America, Canada or any of the alpine areas will agree, its just the lack of insulation in the walls etc. It does puzzle me to an extent that with the climate being warmer than the UK why the houses are so much colder, in Chch we have tended to put it down to the fact that its all built on a swamp, but if its that cold in other parts of the country it puts the khybosh on that theory. Timber wall cavities can be foam filled, insulation can be put under the floorboards, and the loft is the easiest one. High ceilings make a place difficult to heat and my own feeling is that a two storey house is warmer than a single storey.
The new builds in Christchurch area often have double glazing and the current building regs have reasonable insulation standards, they are more expensive than the older houses though, so to a large extent you pays your money and takes your choice.