>>2923982
even a crap wall construction has as some insulation value to it so you get up to modern standards by adding 5 or at worse 10 cm.
>>2923982
a layer between the insulation and outer siding that stops any wind or air draft, yet its not air/moisture proof it has to breathe to prevent mold. probably has a better english name than windbreaker. google isola, tyvek or mataki thoose are the product names i remember.