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

Without an enthalpy exchanger, I wouldn't do it... that gets quite unpleasant in winter.

Thanks for the various encouragements

Briefly about the controlled residential ventilation: That is already rounded up, better too high than too low. I have already included the pressure switch for a hefty 1200 euros. Price for controlled residential ventilation with installation is around 7500 all in. But it is still on the kill list, at least until several comparison offers come in (roof, drywall, doors)

Definitely do it for the price! That’s a great bargain. Controlled residential ventilation in the south is normally around 10-15 thousand euros with the current construction prices. Anything below that is very cheap. We paid 14 thousand euros (enthalpy and Connect included), it was a bit more expensive because it was important to me to be able to clean the pipes myself and to have inspection doors on every floor.

Without an enthalpy exchanger, I wouldn't do it... it gets quite unpleasant in winter.

On the other hand, we don't have that (Pluggit doesn't offer it at all) and we don't miss it either. The lowest humidity this winter so far was 48% in the living area.

We don’t have that one (Pluggit doesn’t offer it at all) and we don’t miss it either. The lowest humidity indoors this winter so far was 48%.

This is really still acceptable. In our rented apartment, it always drops to 30%. (KfW 40+, PB, ETICS, Paul Focus 200) An enthalpy heat exchanger is firmly planned there.

We don't have that one (Pluggit doesn't offer it at all) and we don't miss it either.
Lowest humidity this winter so far was 48% in the living area.

First winter after construction?

2. Winter.
Move-in July 2017
Construction moisture should be gone.

However, we cook daily and weekly 2 loads of laundry are dried in the house. In addition, we have "only" 20.5° in the living rooms, 21.5° in the bathroom, 16.5° in the bedrooms.

I think all of that plays a part in keeping the humidity at an acceptable level.