Financing land and house? Taking out a mortgage? Construction costs?

Sorry, but I can't quite believe that. What do you do when it's windy and the windows/doors slam shut on you? Or how do you manage it in winter at -10°? Hasn't it ever happened to you that you forgot to close a window again after, for example, showering and left the house?

Then I close the interior doors or they close by themselves anyway. I ventilate at all temperatures. We don't make a distinction there. I have also forgotten open windows in the bathroom. But that is rare and the heating is off when it’s cold and the bathroom door is closed, then it just stays open. I have never had a desire for [Kontrollierte-Wohnraumlüftung]. It is certainly not wrong either, but definitely not a must.

It's certainly not a must - and in spring/autumn I also like to have the window open with a fly screen when the sun is shining in. But in general, the ventilation is really great, especially when it's cold because I hardly air out (I'm a frostbite) and the man is always complaining about the bad air - and then in the evening while watching TV he throws the terrace door wide open every half hour and I freeze and complain back... no, such a ventilation system is really practical. If it's properly adjusted, of course. And that's not easy either, most installers can't do it properly or find it too complicated.

Sorry, but I can't quite believe that.

What do you do when the wind slams your windows/doors shut?
Or how do you handle it in winter at -10°?

Has it never happened to you that you forgot to close a window, for example after showering, and left the house?

For the last 2 days, we haven’t been able to ventilate at all. With the storm, I would be glad to have a controlled residential ventilation system.

If we were to build again, I would definitely have a decentralized controlled residential ventilation system on the must-have list.

We also had storm winds of nearly 130 km/h and still ventilated, just for a shorter time than usual and of course not exactly when everything outside was raging. But how often does that happen in a year? So for us, something like that is not a must-have, even if, as I said, it certainly doesn’t hurt. But if you have to be really strict with the budget, you have to set priorities, and everyone sets them differently. We are rather undemanding anyway, at least when I read here in the forum what some consider indispensable.

Sorry, then your site manager it is. Buderus Logaplus Logavent HRV2... Having it installed is not that far yet

I took a look at it. I fail to see why he installs the unit for you at that price including material. After deducting material and labor, he makes no profit from it. You must notice that too. But you might not care anyway :-p