Unpredictability of construction costs - Will the project fail because of it?

But if you do not comply with the minimum standards according to BayBO, it is not a lounge and therefore not living space for permanent residence.

What does the person who actually drew the plan say? They are responsible for ensuring that all requirements are met, especially for a detached house.

That can't be true that the energy consultant is giving me incorrect information? He just wrote again that the basement meets all the criteria for the KfW.

The lady who drew the plan is employed at our construction company.. I don't think I need to say more..

Thank you for the somewhat encouraging feedback. The first step is the phone call with the bank. Depending on the outcome, we will decide which options we have.

Which bank are you financing through? Sparkassen, Volksbanken, ... are probably very lenient there. I've already had the discussions with Volksbank. Direct banks probably not so much ...

I have now looked into the BayBO. According to Art. 45, the ceiling height of 2.40 m does not apply to living rooms in residential buildings of building classes 1 and 2. Am I wrong if I find this applicable here?

This can't be true that the energy consultant is giving me incorrect information? He just wrote again that the basement meets all the criteria for the KfW.

The lady who drew the plan is employed by our construction company.. I don't think I need to say more..

The KfW assumes that the building regulations are complied with. They don't need to define themselves which requirements the building body must meet to be approvable.

Thank you for the kind assessment! By the way, there are people behind this. We know that we have no idea, so we specifically went to the Bauherren-Schutzbund who were supposed to review the contract and supervise the construction. That was probably wrong again.

Yes, and I am a person who can assess you quite well regarding your knowledge of house building and the role of construction manager. That is not an insult, but a fact. The two or the one who suggests that you should take on the construction manager role does not have your best interests or your house construction in mind.

I would currently really not aim for a single trade contract award. At best with a well-connected architect who has good connections to the most important companies. Everything else is currently difficult because, as a small, unknown client, you rank very, very low in the priority for the companies. On top of that, the inexperience, which is a very bad situation in such hard-to-plan circumstances as right now.