New construction DH, hillside location in Hessen - feedback on the floor plan

You would have to explain the second part of your comment to me again, please.

Why do you doubt the wastewater disposal? The basement toilet is located above the sewer level. And why the attic?

We will try to solve the issue with the outside stairs as best as possible, but due to the slope and the plot, no other development is possible.

In other words: just draw the waste pipe for the toilet in the attic floor through the plan across all floors down to the connection. Are there already any ideas? If the pipe below the basement is still above the sewer connection, it should of course be no problem, as long as you still have a slope until then.

You mean what you want is not possible otherwise.

This is a semi-detached house. Wouldn't it be worth considering placing a wide shared staircase in the middle instead of 2 separate chicken ladders? However, the guest toilet would then have to give way – maybe to the basement, if the slope really fits there. In my opinion, it is actually an eye-catcher – but not in a positive sense. But I am happy to be convinced otherwise when the views are complete.

In other words: just draw the downpipe for the WC in the attic floor through all the floors up to the connection. Are there any ideas yet?

Moat with drawbridge