I saw some new dwellings being built in northern Finland and the walls were incredibly thick with insulation, the windows are often triple glazed as well.
I reckon the walls I saw were at least double that (but it can get down to -40 or lower there). The houses I stayed in over there were incredibly warm with no drafts.
I saw some new dwellings being built in northern Finland and the walls were incredibly thick with insulation, the windows are often triple glazed as well.