Payment plan suspicious

Hello,
after extensive research and many appointments with various companies, we have received an offer from our preferred company.
Do you think this payment schedule is acceptable? My father thought that too much is demanded at the beginning and too little for the last part of the construction measures.
Here is the plan:

15% after completion of foundation
10% after completion of basement masonry and ceiling (without facade)
10% after ground floor masonry and ceiling
15% after roof frame
15% after completion of roof covering
10% completion of interior plaster
14% after completion of heating and sanitary rough installation
10% after completion of screed
3% installation of stairs, interior doors, tiles
3% after acceptance and handover of the house

Especially the last 3% seem too little to me. What is usual and homeowner-friendly in this regard? At which point is the house sealed (windows, doors)?

In addition, the contract states that the company issues a performance bond of 5% of the construction contract sum. Isn't that far too little? What can I reasonably demand here?

Thank you very much for your effort!

That would be a solid 65% after completion of the enclosed shell.

That would be significantly overpaid.

That would be a solid 65% upon completion of the closed shell.

That would be significantly overpaid.

Agreed!
Please renegotiate.

Okay. I already suspected that. I will try to have the conversation again. What do you think about the 3% after acceptance? Is that okay? And the 5% performance bond? Is that sufficient?

Thank you very much in advance!

As far as my lawyer has correctly informed me, the 5% are stipulated in the [Baugesetzbuch].

Hello,

Do you think this payment plan is okay?

The "language" of the forum is the informal "Du" ;)

15% after completion of foundation
10% after completion of basement masonry and ceiling (without facade)
10% after ground floor masonry and ceiling
15% after roof structure
15% after completion of roof covering

Up to the completion of the shell - by the way, I don’t read anything about windows - these would be 65%; I would always advise against accepting such a payment plan.

Above all, the last 3% seem too low to me. Besides, the contract states that the company will issue a performance bond of 5% of the construction contract sum. Isn’t that way too little? What can I reasonably demand?

That is interesting, because this very point - combined with a 5% performance bond - is absolutely fine _if_ and _only if_ the payment plan were fair, which from my point of view it is not. Just imagine, after the shell is completed, you reach a point where no more talking is possible, the relationship breaks down. With the remaining 35% (and I cannot say for sure if the trades for windows and front door are even included in the 65%), you will never be able to finish your single-family house.

However, I could also imagine that the payment plan is not negotiable at all; there must be a reason why it is applied as it is. Please keep us updated on what your efforts yield.

Rhenish greetings