It's -17C now, a couple weeks back it was -29C... I have 100% (geothermal) heat pump heating and it's 24.5C inside at all times. The buildings/houses require a

It's -17C now, a couple weeks back it was -29C... I have 100% (geothermal) heat pump heating and it's 24.5C inside at all times. The buildings/houses require a good thermal insulation but heating, itself, is not an issue.