Buy or leave?

No. You could place the garage on the southern boundary, exactly in line with the front building limit. Two parking spaces where you had originally planned the garage according to variant 1. Of course, you have to check this again carefully with the floor space index and the front garden area, but according to a visual estimate it should work. However, there will be no usable garden anymore. And the floor plan with limited south-facing windows must also fit with this.

Do you really mean here? Our terrace is supposed to go there.

The garage(s) can and should be placed here or there. Actually rather at the top/on the border to the northern neighbor.

See the red scribble. In any case, the garage(s) must be inside the blue box

The access above is shorter. Also, do not forget.

In any case, the garage(s) must be inside the blue box

No. It only has to be behind the front building boundary.

Do you really mean here?

No. Here: However, your duplex can only be 14.50m wide like this, provided my determined plot width of 23.50m is correct. Do you really have to provide 4 parking spaces? If not, a single garage can be placed in the north and south respectively. That gives you 2m more for the building body of the house, so it would be enough for your desired width. Both solutions are only possible if you are granted two driveways.

My architect came back from vacation over the weekend and I boldly called him on his mobile this afternoon and asked when I could come by. I was happy when he said come by with the documents in half an hour :)

I presented and explained everything. He made it clear to me in a few minutes that the garages cannot go where I want them to.
Besides, he would build terraces and gardens facing west and not south!

He said build one garage on the north wall and the second in the semi-detached house on the south side or one each on both exterior walls south and north.
I don’t know if I want a garage inside the house but maybe both on the north wall would be an option.

In any case, he will somehow find space for two garages and gave me his blessing for the purchase of the property.
I also had to learn that since there is a development plan, everything can be built without approval or any applications.

I don't know if I want to have a garage in the house

I think it's nice when semi-detached houses are not mirror images. Do you actually know this thread: ?