Basic line planning property slight slope

The wastewater transfer shaft is like drinking water at 1.50m

Also in order of importance: shortest distance under inaccessible surface > few direction changes > short total distance

I see it the same way: first aim for the excavatable area as the "saving shore" and then go to Rome by the shortest route possible, trying to include as few slow-flow sections as possible.

Option 4 goes directly out from both kitchen and bathroom, but it is the longer way and a short overlap for drinking water and bathroom wastewater

Does anyone have an opinion on the advantages and disadvantages of variant 4?

Variant 4 is better than 1 and 2. Variant 3 is cheaper than 4. Ask the architect what speaks against 3.

I'll ask if it is allowed in Brandenburg to lay longer distances inclined outside the base plate. If anyone in the forum knows, please let me know.