Does this mean ideal building design is as cool as possible and using energy for heating?
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.
Houses built in southern Italy are like that (white paint, shutters on windows, ...)
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.