Payment plan suspicious

I find it much more gruesome that after laying the screed, only 6% is still missing. Very expensive parts come in between the screed drying and the house completion. And a lot of time passes with fast construction companies during the whole process (if construction takes 4 months, 4-6 weeks of drying is 1/3 of the time, during which you have basically paid everything but have not yet had everything installed in the house).

15% for aligning and 15% for putting up a few roof tiles is definitely too much! Here, 10% needs to be removed and at least added behind the screed drying (for example, tiling work finished). As already mentioned, windows are missing, which absolutely need to be included in the payment plan.

Everyone always insists on the last payment. It has to be paid suddenly right before handover (definitely before moving in). Otherwise, there are no keys :) The last payment is hardly any leverage, even if everyone likes to see it that way beforehand. You also have to look at how much these 3% are in actual euros. For really serious defects, the last pennies don't matter to the construction companies; for minor issues, they do anyway. Much more important than the 3% or negotiated 5% at the end is that you never pay (much) more than what you have already received. 65% after the shell construction is already quite harsh, but 6% still open after laying the screed is really not acceptable at all.

P.S.: The financing bank can also reject payment plans or cause the financing to collapse. The payment plan must be submitted for the financing.

Thank you very much for your advice. I was able to renegotiate the payment plan. Now we pay exactly 55% after the shell is closed (even including windows :)). For the negotiation, I proposed a payment plan suggestion from Bauexperte from another post. Many thanks also at this point to Bauexperte for the tips.

Can you post the payment plan here? Thanks in advance.