I'm not an expert at all, but from my understanding, the ideal building is one that has so much insulation that its interior is kept at a set temperature with very little cooling and heating needed.

You still need to get rid of heat generated from inside buildings and potentially deal with the impact of ventilation.

There's heat recovery ventilation.

You also need to exchange air with the outside so that CO2 doesn't build up with people inside.

Depends on the climate.

Houses built in southern Italy are like that (white paint, shutters on windows, ...)

But in the Sweeden the opposite, optimize for heat.

> But in the Sweeden the opposite, optimize for heat.

Not that much. As you mentioned just above, shutters are a layer of insulation. In Sweden, they have big glass windows and no shutters. The purpose is clearly to get the tiny bit of daylight in winter for health sake, but in terms of insulation, it would be better to have shutters, and smaller windows.

The other way around.

Generally it is best to create an insulated box that stays warm when it is very cold and then cool it down when it is hot - because the reason it gets hot is due to increased energy outside (normally the big glowy thing in the sky) and that energy can be captured and used to power a house sized fridge.

Energy to warm things up tends to be the sort of energy we can't really use any more.