> What you describe is the rule in most Western countries.
Say what now? Is the UK the only western country you've visited? because what they describe for Australia is not the rule of mainland western europe, serious insulation and at least double paned windows was the standard in the 90s.
Double paned windows are hardly some kind of best practice. The Mediterranean countries are still poor. Of Western Europe, only Germany and to some extent Ireland appear serious. You also have smaller jurisdictions, e.g. Brussels where some good work is going on.
Mediterranean countries also get less harsh winters, especially in the last years people have preferred installing cheap stoves rather than doing all the work required to properly insulate buildings from the 60s (roof, external insulating coating, window frames, condensing boilers, etc).
They also have more harsh summers. To an extent, in some cases, the vernacular protects them from that with high thermal capacity and decrement delay to buffer energy transfer. But if you then have a fashion for large windows... not so much.
And all that doesn't help with ventilation and maintaining healthy levels of fresh air.
Say what now? Is the UK the only western country you've visited? because what they describe for Australia is not the rule of mainland western europe, serious insulation and at least double paned windows was the standard in the 90s.