Build monolithic according to KfW55 standard with a basement, but it makes sense!

Hello everyone,

I actually already feel sorry for asking this question. Since it has already been indirectly discussed several times here in the forum. My concern is not whether KfW55 makes sense or not, I have left that behind with the idea of a controlled residential ventilation system.

Actually, I didn’t want to build to KfW 55 because of the basement, but since we wanted to build with a controlled residential ventilation system from the start, a heat pump is mandatory, and I am considering a photovoltaic system (without storage) because an electric car is available, our architect mentioned that KfW 55 would be a sensible standard to achieve (also because there is optimal south orientation).
It should not be withheld that we are planning a small chimney. (similar to Plewa Classic)

Since we still have at least 4 months before we approach an energy consultant, I would like to ask the following question.

What do you think, what requirements would still be missing for us to sensibly achieve KfW 55?
The draft plan still has a 36 cm wall planned. Do we need to go up to 42 cm? Or are triple-glazed windows sufficient? Does the basement need to be heated? I mean, it will not be a living basement, but it should be possible to stay down there.

Has anyone here already built monolithically with a basement according to KfW 55? Certainly, right?

Yes, we are currently building a monolithic KfW 55 house with a basement.

36.5 cm Unipor Coriso, air-water heat pump, triple-glazed windows. The basement was insulated with 12.5 cm perimeter insulation. The floor structure in the basement has exactly the same insulation requirements as the ground floor and upper floor.

Photovoltaics are also planned for the roof. We are very close to the 40 threshold.

Why are you only approaching the energy consultant in 4 months?

: I was exactly hoping for such information.

Where else would you have had to improve to achieve Kfw 40?
Do you have a controlled residential ventilation system?
Is your basement heated? Do you have a utility or living basement?

Regards
Arthur

Why are you only approaching the energy consultant in 4 months?

We have just completed the preliminary design with the architect and since the development and surveying, and thus the building permit, will be submitted by us for the first time in about 4 months (planned), we still have a little time.

Insulation of the basement floor slab would have been necessary. Controlled residential ventilation, of course. The basement is heated. At least the hobby and technical rooms as well as the hallway and the laundry room. The 2 basement rooms are not.

I would involve the energy consultant promptly. Definitely before the construction plans and also regarding the costs.

Yes, I know the energy consultant could probably tell me this better, but it still occupies my mind a lot. Would the following conditions also be sufficient for KfW 55,(?)

- Air-to-water heat pump
- Controlled residential ventilation
- 12.5 perimeter insulation
- 36.5 cm Unipor Coriso
- only double-glazed windows