Needless to say that thermal insulation is awful in IT.
https://lawline.se/answers/hur-kallt-far-det-vara-i-hyreslag...
Personally I find if it's especially cold outside, I need to put the thermostat up to compensate.
When it’s -25C out, not so much.
Japan can actually be a case study of that: detached homes on Honshu (the main island) generally have poor insulation, in winter they tend to be quite cold and spot-heated (using kotatsu and kerosene space heaters, with heavy clothing).
On Hokkaido meanwhile, good insulation (including double or triple pane windows) and central heating are common (the island has insulation regs and there are loans dedicated to properly protecting against the cold), and inside temperatures tend to be cosy. It’s a regular occurrence that Hokkaido residents catch colds when visiting tokyo in winter, because they don’t have the habit of bundling up inside.
Though when it comes to Honshu, one of the justifications for the lack of insulation is the difficulty of keeping indoors drafty and dry during the extremely wet summer, to avoid the walls outright rotting on you.
However that doesn't dictate inside temperature. Well, maybe if you heat with firewood - you will get high/low temperature rises/drops. But people just like 20+ inside. 22-23C for me is comfort. Currently 24C at office - higher is out of comfort, but happens.
Someone like lower temperatures. Someone wants to save some money and keeps temperature lower than comfort.
And yeah, warmer climate results in colder inside temperature, because houses are not very well insulated and may not have advanced heating systems. But that's just experience from few data points I know of (and some HN comments confirms that).
I think that its all about the windows. In warm climate regions they are made to allow air circulation.
Windows, walls, roofs, ceiling heights, …
In warm climates until you have AC you want shade and air circulation / drafts.
Having no roof insulation is not much of an issue (might even be advantageous to trigger forced airflow) as long as you’re far from the roof. Likewise high ceilings keep the heat climbing above head level.
And imperfectly adjusted doors and windows with dodgy (or missing) seals isn’t a bother when it’s not an advantage.
In cold climes none of those is really acceptable unless you want to absolutely nuke your bank account on heating, at least if the house is anything more than a place to sleep in.
