Construction costs are currently skyrocketing

And what is different about that compared to the slightly open window?

Theoretically, the heat recovery. But a fan in the bedroom would drive me crazy.

A lot of it is simply a matter of habit. I always wonder what my sister-in-law needs the pile of extra thick cuddly blankets for in her 26-degree warm living room. :D Probably the Antarctic ice would instantly grow by a meter if she heated her house less tropically.

There is a heat exchanger installed that recovers most of the energy. When ventilating, the heat is simply lost.

Ok. But then the device also needs electricity, right? So just a hole in the wall is not enough?

And it’s also not the solution if you want it warm during the day and cool at night.

A lot of it is just a matter of habit. I always wonder what my sister-in-law needs the stack of extra-thick cozy blankets for in her 26-degree warm living room. :D Probably the Antarctic ice would spontaneously grow a meter if she heated her house any less tropically.

There are such chilly people. They put on winter clothes at 8 degrees Celsius, dress the kids in snowsuits, and from November on, the house is not left because everyone is freezing. Visitors, on the other hand, come in summer clothes. People are different. The only question is whether one can still afford such warm living spaces for long. Between 26 degrees and frost flowers on the windows is a wide range.

A lot of it is simply a matter of habit.

And part of it is also imagination. Sorry to have to say it like that, but the discussion reminds me of a certain person who believes that they get sick from air conditioners in the summer and heaters in the winter. Even when they are not running at all ;)

Ok. Then that thing needs electricity, right? So simply a hole in the wall isn’t enough?

And it’s also not the solution if you want it warm during the day and cool at night.

Yes, of course it needs a little electricity. The ventilation is mainly about getting fresh air into the house without losing heat. The only good solution for warm days and cool nights is two separate rooms.

Following the discussion, in my opinion the energy prices are still a bit too low. :D