Building a single-family house with/without a basement on a small plot

No, it does not. Binding for you is first of all the development plan and it says II+S in a circle. So you have to build 2 VG plus the SG. How SG is defined you can find out in the building code of your federal state, which we still do not know.

It is in Bavaria, I actually wrote that above already.

We also have a traffic-calmed dead-end street at the end of a row of terraced houses, there actually only two neighbors drive behind. The "front garden" is about one meter deep like all the neighbors and without enclosure. That is practically our footpath, there are no problems because there is no through traffic and mutual consideration is not a foreign word

That is good to know. Surely we will also exchange information with the future neighbors south of our plot to find out how they plan it.

Oh yes. I just saw it in the [B.plan], that's Litzendorf/BA. Hello Mr. Neighbor, this is [ERH]. What is the name of the development area? I can't find the plan on the municipal website, is it available online somewhere?

Oh hello! No, unfortunately it is not available online and somehow I can't post the PDF file here. The construction area is called "Aufseesianische Wiesen", on the internet you can find the projects of the architects who participated in the competition.

I tend towards a basement if the budget allows. Rather a carport instead of a garage and a smaller storage room behind it.

150/160 sqm is not much space for 3 children. Especially since a lot accumulates that is passed on from one child to the next.

I would plan for 3 children. Maybe design the walls so that rooms can be combined with a wall break.

Well, 150/160sqm and small for 3 children, that also means very high demands. I grew up, with 2 siblings, in a house which, after attic conversion, has 120-130sqm. Sure, it has a basement, but generally that fits, even if not with the modern obviously much larger rooms. But if it works out without too many compromises, I would also plan with a basement. For the rooms, either so that some can be combined again or designed so that one large room could be divided into two decent children’s rooms (drywall).

But the front door practically right on the street, even if barely trafficked?? I don't know...

Nope, my first thought would be this: Although I don't know the details from the development plan regarding the edge development with outbuildings.