Questions about the payment plan

big hammers are rather unlikely with such payment plans, after all the company probably wants to build trust with 20% at the end.

The trust would be even greater, however, if the last installment did not have to be paid before handover.

The beautiful Construction Contract Act indeed states in 641 that the remuneration is due after (!) acceptance.
By linking it, the clause in the last part here prevents retention due to defects according to 641 III.

The clause is, in my opinion, invalid in general terms and conditions.
The legal consequence would be the invalidity of the entire payment plan. The Construction Contract Act applies again, i.e. 641 Construction Contract Act: 100% money only after acceptance....

Because: According to the Construction Contract Act, the contractor is obliged to provide advance performance. But if you pull out this hammer, the contractor won’t build a house for you....

Or in other words: You have paid 80 or 95% and possibly may not be allowed into your house...

Thank you very much for your valuable suggestions! We actually had a good feeling about this [BU]! Many trades are certainly interlinked in such a way that after the completion of a construction phase, many services are rendered and are to be paid for! I will have the contract checked and will report back.

Our contract states that payments are not due if defects occur during acceptance and as long as these are not fixed. That would be sufficient. What bothers me is that in the end you only have 20% outstanding, but theoretically all trades that were not previously listed could still be missing. From my point of view, the house is overpaid at the latest from point 9.

That would be enough.

Not if the contractor is currently disputing the existence of a defect.... and the demand is: now come on, where’s the money....

The critical point in installment 10 is that it is unclear what (!) must be completed (hopefully this means the ordered complete building essentially...)

The clause is, in my opinion, invalid in the Terms and Conditions. The legal consequence would be the invalidity of the entire payment plan. The Building Code applies again, namely § 641 Building Code: 100% payment only after acceptance....

Because: According to the Building Code, the contractor is obliged to advance payments. But if you pull out this hammer, the contractor simply does not build a house....

that is not entirely correct it is probably the case that the invoice is due upon acceptance, BUT § 632A Building Code applies. Partial payments can be demanded. This is a guarantee for both sides; if the company goes bankrupt, you still have something, or if the client goes bankrupt or does not want to pay, the company has something!