Is the general contractor payment plan acceptable? Thanks for tips

That's right, all questions that a good consultant clarifies in advance. At least a capable one can answer upon inquiry.

But I cannot submit the €357,000 as financing if the offer is €320,000

Why don't you include a budget for upgrades in the contract draft and then submit it accordingly to the bank?

Although we now have the exact costs, at the beginning we did it this way. The general contractor went through the wishes with us (tiles are a bit more expensive, standard sanitary fittings are not enough, etc.) and roughly calculated what that would cost with a calculator. Then he made a non-binding list of the points for the contract and included an "upgrade budget" in the contract draft. You haven't signed the contract yet.

In the meantime, we went through everything in detail and now have an exact list of costs as well as total costs. That goes to the bank. Although it is also the case here that, for example, we received a rough estimate for the outdoor facilities from the general contractor, which is not part of the contract, and we will obtain offers later. For the bank, that is sufficient as long as it is not completely exaggerated.

I cannot say anything about the result yet, we are currently applying at ING.

I can already tell you that the current processing time for large loans (I believe the limit was €500k) is 20 days. So plan accordingly.

after 20 days