Notice Corelogic has a report out today which states how much energy efficient new homes are!
If you are in a principally constantly cool or constantly hot climate, I would say, yeah.
But my experience with insulation ( though is bit limited) is that it works well for a short period of time, say 3 to 5 hours. But if it's constantly hot it will succumb then you have to use cooling to bring it down.
The thing is, if you don't use cooling, and a place is heated from the sun, it takes an awful lot to cool it down...if it was uninsulated, it responds to the ambient cooling of a night much, much quicker!
Conversely, if you havent artificially heated the place, it takes a long time to warm up, say overnight and into the morning...uninsulated places will be warm by 10.00 a.m say in Southern Qld winter, but insulated won't warm up till about 1.
