Houses have good insulation I take it? Not like here
Tbh not really its a 60s built wooden house very typical. Ive only got to see inside the walls when we changed some windows.
2 layers of lagging/insulation made of god knows what fibreglass woven stuff (rockwool they call it ) whatever was around then.
Windows are double and triple glazed. whole house is razed about 50cm from the ground and there's a 1m "basement" covered in sand and lined with some kind of thick plastic sheeting to stop moisture and "cold"
The roof is sheet metal, nearly everything is built out of it here... at first i was disturbed how awful it looked, after being so used to slate rooves, but now its just normal and extremely practical in the climate.
i guess there's a reason they built them like this, cost effective and warm enough its very easy to keep it 21deg inside....
Its unboreable warm in summer in sun facing rooms, mostly due to the length of the days.
We dont have aircon but its very common here, Hicksville USA, rural America, is basically Sweden.