We have been living in wellington, and it is third world with respect to heating. We rent a house for 500+ a week and we were told that there is good insulation and house is warm. It is winter now and the interior temperature is much less than 10 degrees in early mornings and the nights. We have clearly noticed that the interior temperature is only 3 or 4 degrees greater than outdoor temperature. Our power bills are enormous and it is becoming unsustainable. My advice would be to rent for a couple of years and then buy a house which is warm or does not cost you a lot to warm it. Never sign up fixed term contracts for a year, if you are not sure about the house, unless you take an expert with you for those 10 minute lousy house viewings. Everything looks splendid in the summer, and once winter comes you know what you signed up for.