> 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.
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.