Energy calculations for new construction, KFW loan, KFW subsidy products

I am currently planning the construction of a new single-family house. Unfortunately, the house and estate architect of my in-laws is based in another European country and has no knowledge of German energy regulations.

However, I would possibly like to take advantage of a KFW loan. The problem is that I have no clue which energy requirements our future house meets, or which measures we can take to raise it to the next better standard.

So far, the following are planned:
- solar thermal collectors on the roof to support hot water
- controlled residential ventilation with heat exchanger

We are still debating triple-glazed windows.

The structure of the exterior walls is currently still a mystery to me. There are supposed to be some differences that then affect the energy efficiency of the house. I still need to read up on that.

Does anyone have tips for me or places I can contact that carry out such an energy calculation? I know that this is usually done with the architect (who cannot or will not do it in our case) or the builder (we don’t have one), but in our case, the planning mostly consists of groping in the dark, reading two-thirds knowledge, and relying on the brother-in-law who has done this several times and says that everything will be fine.

Good evening,

.... but for us, planning mostly consists of groping in the dark, reading up on two-thirds of the knowledge, and relying on the brother-in-law who has done this several times and says that everything will be fine.

Best conditions for everything to succeed ....

Rhineland greetings

Can only agree with the construction expert. They are cutting costs at the wrong end. You need a specialist who evaluates and confirms your energy measures. They have a) the expertise in this field b) the necessary software

If you want to take advantage of cheap KfW funds, you can't avoid spending money, both on the measures and on the expertise. The KfW is very strict with the allocation. Which is also understandable, otherwise anyone "I'm just building a house on the side" builder could arbitrarily request money.