Development plan eaves height - max visible wall height

For us, it is not apparent whether the ground floor would then be in the basement or at street level.

For us neither without a complete development plan.

have no contact with the architect and unfortunately do not understand the development plan 100%,

so area b

For your question, a complete development plan is required, which a) is textual (you have provided that) as well as pictorial... and b) the site plan – which you have neglected to provide.
Your question

whether this would even be possible.

cannot simply be grasped or answered that way.

Here is a quick sketch of the problem

Exactly the questions in the sketch are answered by the site plan for the development plan. Unfortunately, you do not want to show it to us.