Yes i agree the standard is not the same all across europe .spain in praticular has a shocking standard of construction.
Regards the hot climate in Australia i think thats reason enough to invest in insulation. Look at Scandinavian countries with a temp range -20 +30 house is easy to heat and keep cool.
Paying money to Heat water in this country is crazy .
If you are looking at a new build have a look at ICF construction which is extremly efficient but comes at a price
