However I would only put the heater or aircon on somewhere between 40-60 days a year and only for a couple hours. And often it's just to take the chill out of the house or cool the bedroom before bed. I have a modern well insulated house which is a rarity in Melbourne or Australia in general, houses/apartments are built like shit here.
Australia has some of the worst built houses in the western world, especially houses built in the 20th century. I think the average was 0.5 stars out of 10. Thankfully we have the most amount of solar of any country so we are offsetting the crappyness.