...I have never seen a house where a garage is placed the wrong way around to the house entrance. I somehow can't imagine such a variant either. Everyone places their garage with the garage entrance facing the house entrance. Either on the side or from the front but never the wrong way around.
That is not correct. I have seen many things: under the house, on the side, behind the house, at the other end of the property... A colleague has a narrow piece of land with the house entrance + one parking space at the front, the double garage (with 2 cars) at the back. In between there are 25m of covered walkway and a very nice garden. There is a solution for almost everything.
It also depends on priorities. Of course, it is nice if you can go directly from the garage into the house. But only if it is planned sensibly. It’s more like an additional hole in the house. Most people don’t want to admit it, but in almost every floor plan, a sensible garage access generates additional square meters. However, no one is willing to pay for that since it is "just a garage access." On the other hand, it also doesn’t make sense to carry groceries completely around the house once. I am a fan of "form follows function." Afterwards, you can still think about how to make the practical things look a bit nicer.
Just talked today with the land seller and the city, the building boundary only applies to the house, not the terrace.
It’s usually not that simple, because this only applies to terraces founded on existing ground (i.e., no earth movement), that have no roofing, and depending on the federal state, it plays a big role whether they are directly adjacent to the house (in which case setback distances often still apply).