Thank you Musketier & Yvonne!
In the meantime, I have looked at the provider's page; there the house is specified with a 44 cm knee wall. And took another look at the drawing of the OP – of course, you were right Musketier. Yesterday I must have been blind, sorry.
The single-family house in your pictures looks visually very appealing; on the other hand, the question arises for me as to why I should give up usable floor space per floor in favor of a one-sided higher knee wall of just over 2.00 m by "x"?
In the hand drawing of the OP, the approach of the double-sided shed roof was chosen differently, as the house itself does not lose any footprint. The question remains whether the BF allows this measurement, whether the permitted ridge height is maintained, and what additional costs the OP has to expect.
Rhenish regards