Usable basement: Insulate, heat, raise ceiling?

If the basement remains outside the thermal envelope, incorporating the controlled residential ventilation into the basement is certainly not a good idea (or probably not even permissible). If you still want to ensure basement ventilation (possibly even without windows), Maico offers special fans (e.g., Maico AKE 150). These devices continuously measure the temperature and humidity both outside and inside, then determine the dew point and ventilate the moisture out as needed. Similar to decentralized ventilation, at least two fans are always coupled together that alternately push air in and out to ensure air exchange throughout the entire room.

If the basement remains outside the thermal envelope, including the controlled residential ventilation in the basement is certainly not a good idea (or probably not even permissible).

From my point of view, this only means that the controlled residential ventilation of the basement and the living area should be separated, i.e., two central controlled residential ventilations should be installed in the house.

The thing with the controlled residential ventilation, I have already found out that it doesn't work.

We are investigating how we will handle the ventilation.

If the basement remains outside the thermal envelope, including the controlled residential ventilation in the basement is definitely not a good idea (or probably not even allowed).

We have done this in both the last and the current house. There have never been any problems so far and personally, I believe that the advantages outweigh the disadvantages.

So we have this both in the last and the current house. There have never been any problems so far and personally, I think the advantages outweigh the disadvantages.

The technician from Gussek Haus said that due to the heat recovery of the controlled residential ventilation, we cannot include the unheated and uninsulated basement.

Oh dear, I just had my own experience with Gussek Haus in building services and we canceled our construction contract after half a year, I hope you have better luck. Just read the data: outside 1.1°C, supply air 16.1°C, basement 18.4°C. Yes, some heat is lost, but at least regarding moisture there is no problem. On the contrary, I am extracting moisture - and at the same time using the waste heat from the technical room in the basement.