Installment plan - Two-story house without basement

Thanks for all the answers! Despite the negative feedback (I will present the payment schedule to the potential financer...) it would be interesting for me if someone could additionally share their own experiences with HomeMaker - to report how it went in practice...

Good to know that normally only about 60% of the total amount should be paid after completion of the shell.

Hello everyone, Homemaker informed me in response to my inquiry that the payment schedule can be discussed. Since I work as a financing broker, it also has to be adjusted. Many banks only pay out according to the broker and developer regulations. And the payment schedule fits there. However, I can understand that Homemaker wants a payment for the plans. I already pay an architect even if I have not yet built. Greetings from Dortmund Albert

A construction company offered me the following payment plan for a two-story house without a basement on a slab:

5% before the planning meeting (is that normal?)
10% upon submission of the building application/building notification
15% upon completion of the slab
15% upon completion of the ground floor walls
15% upon completion of the upper floor walls
10% upon completion of the roof truss
5% upon completion of the roof covering
8% upon completion of window installation
5% upon completion of the rough installation of the heating system
3% upon completion of the rough installation of plumbing
2% upon completion of the rough installation of electrical work
5% upon completion of the exterior plaster or the facing brickwork
2% before acceptance, secured by the company's performance bond

The first installments seem very high to me – what is your opinion? Thank you very much for your answers!

Upon handing over the plans, yes. But not already 5% before the planning meeting. In my opinion, that is highly unprofessional.