Now I totally get your point. That is bad design. Even as to just clean windows. Our windows can be opened inwards totally or just slightly tilt it.

I see your point. I do not see how you cannot cover the outside of thr window yet. I live on the 4th floor of an absolutrly insulated building in a much hotter region than Scandinavia. Covering window and letting air go during cooler nights keep temperature at approx -6 compared to outside temp. If outside temp doesnt go below say 26 during the night, then its air conditioning either way, regardless of insulating (but with insulation it remains cooler for longer).

If its still 35 during the night then it will rise to that temperature inside regardless of insulation. Maybe more quickly without it. The point was insulation. If the min night temperature is 35, then you have air conditioner or you die.

Great stuff.

Open all fucking windows during the night and close them and barrier them from the outside during the day.