He stated objectively, with reasons
Well, I can't really see any objective reasons there.
- Risk neighbor in the west builds garage directly in front of the terrace.
That is even very likely. But I find it somewhat bold to say "directly in front of the terrace." The house has a boundary distance of over 6m and a garage may only be 3m high.
there will probably be a retaining wall
... which according to the development plan may not be higher than one meter. Drawing a picture of New York street canyons here is probably a bit exaggerated.
- Garage driveway 5.0m too short, garage with 6m is far too narrow
... those are completely usual dimensions. Anyone who needs more space must buy more space.
- Floor plan difficult to implement with this design
also here: no justification given. The floor plan has already been realized.
- The north surface lies lower than the street according to the OP and is thus not well usable.
Here there is a slight to moderate slope. The maximum height difference along the property diagonal is 2.03m.
Everything has to be "carried downward."
Sorry, that's ridiculous.
- Option of a swimming pool in the south then shifts to the north. Can be done...
The plot is over 700m² large. As if it mattered whether a freestanding pool would be located in the north or south. I believe you only skimmed the thread, so you are missing some facts. In this respect, I can only agree with Yvonne:
I find that cheeky and thoughtless.
But I would never build like that
Then you wouldn't have bought this plot either. Surely the plot would better suit the OP's wishes if it were in South Africa or at least on the other side of the street. But now she has bought it anyway. So how could a solution look like?