How does the process work? Order to the architect? Then bank / KFW / 1000 houses?

Parameters are:
Rate at around 1400
Loan-to-value just under 80% or just over, this has not been decided yet...
Income over 4500 net

How do you know the amount of your loan-to-value ratio when you don't even know exactly how expensive the house will be?

I know because I have to set limits and withhold equity, and accordingly, the loan-to-value ratio will be as it is. We already had a conversation with the architect, and the budget was clearly presented. I’m aware that it won’t stay that way anyway. But the budget simply has to be set—what else should the bank base itself on? Only on what the architect calculates, and if his calculation doesn’t fit my budget at all, then something’s wrong :) But your objection is justified—especially as a calculation basis for the bank, which is why they surely want something from the architect... and I basically have to go there beforehand anyway, or am I wrong.

Regarding the date from which you have to pay the provisioning interest, there is some room for negotiation.
For example, I asked if we could specify a date at least with the year 2018 as of 01.09.16.
The advantage is that if there is still something left at the end and you cannot repay so much at once before the forced payout as necessary, you can still use special repayments twice due to the turn of the year (special repayment for 2017 as well as special repayment for 2018) and thus return borrowed money directly again.

Otherwise, you can also negotiate the amount that can be repaid directly before the end of the borrowing term.

Also (but only verbally) he implied that if it gets tight, this date can be adjusted again later. That has a lot to do with trust. Since the banker has been known to our family for years, we have this trust.
It may be different for you.

The bank’s offer usually lasts about another month. So if you want to start quickly, you still have time before you accept the offer at the bank. And usually it does not get worse afterwards, but is at most adjusted to the then valid interest rates. A reputable bank should not touch the rest of the conditions.
And a reputable bank does not put pressure on you either.
As previously said, your equity will be used first anyway.
I will also only sign at the bank at the very end; they will not run away.

What I want to say is that it is still not all lost.

Sounds not too bad at all :-) The offers I have now with the top interest rates are from an online portal - I had an online consultation here. Unfortunately, my main bank is significantly higher here, especially in the area of lending <80% => I have a 0.4 percentage point difference here. The disadvantage with the portals is that the offers are only valid for a very short time. I don’t know if I can negotiate further here or if this is already the limit.... But I have to say, in the end, I don’t care where the money comes from - conditions matter. If a bank offers me a better interest rate for 20 years than my main bank for 15 years, then I know what I will choose and I think I am not alone here. But I think I will approach my bank again. Do you have any experience with this?

I would have it calmly calculated by the architect. A bank must also check on a solid basis. Loans under 80% are not insignificant either.