Evaluation of Construction Project / Credit Offer

That definitely won’t work. The incomes are not high enough and do not match the project. And 400,000 euros for a KFW40+ house is unrealistic. It would either have the lowest quality furnishings or be only 120m2 without a basement and garage. Both are nonsense.

I am also curious whether the OP can write down his lifestyle that much. But I also find the project somewhat too large given the equity situation. What exactly is meant by the fact that Außenanlagen are being contributed? Are you bringing the trees with you?

My goodness, things are being painted black here again. The OP is 32, his partner probably about the same age, and together they have a net income of 5,200 plus a bonus (which probably won't be zero). Yes, the personal contributions are harakiri, but otherwise I see the project as feasible. I consider 1,600 to 1,800 euros a healthy financing for you. 2.5% repayment plus special repayment should work. Thus, 550,000 as a loan and about 450,000 for the house are possible. That it now means saving, saving, saving is probably clear as well.

Do you already have a concrete offer for your desired house or is it just an estimate so far?

Why are you giving them false hope? You will never, ever be happy with something like that.

We are currently looking in all directions, but we already have an offer from a prefabricated house manufacturer for a KFW40+ house. With proper planning of ancillary costs, etc., we are at almost exactly 400,000€ including additional construction costs.
A solid house provider has given us an offer for a KFW55 house amounting to 370,000€ including ancillary costs; for 30,000€ an upgrade to 40+ should at least not be too far off?

400,000€ for a KFW40+ house with 120 sqm without a basement seems a bit high to me?