Selection of plot, considerations

I don't know what is legally required regarding parking spaces.

The development plan, the municipality's parking space ordinance, or the state building code of the federal state will tell you that.

Usually, enclosed parking spaces are not permitted.

Which house from Hanse Haus is your favorite?

See screenshot in post #55. What makes it the favorite?

No slope.

But a tub, as if the base of the street had been taken from the plots.

But a tub, as if the substructure of the street had been taken from the properties.

What does an ideal building plot look like? Level with the street or just a slight depression? At that depth, does a cellar almost make sense? Concrete slab + possibly QNG insulation + compacted gravel layer would be how high/deep? Hmm.

What we like about the floor plan:

[*]Office on the ground floor
[*]3 children's rooms, similarly sized (which is not so common in standard floor plans with <150 sqm, it feels)
[*]Overall quite compact, without the living area being disproportionately small
[*]Shower bathroom on the ground floor
[*]With the option of larger doors in the dining area, quite a lot of light from the south and west
[*]Hallway with 18 sqm in my opinion sufficiently large, storage room under the closed staircase
[*]Utility room sufficiently large if the heating is not installed in the house (district heating via the large heat pump)

We would close the area hallway - living room hallway - kitchen.

Cons:

[*]Despite knee wall of 1.20 m, quite a lot of slant (the houses further east in the building area have 6.5 m ridge height, ours is 4.5 m)
[*]No finished attic - overall relatively little storage and usable space

I was now thinking of a refill by the seller. Well, there are worse things. Either you dig out, or you just fill it up. Might cost a bit more for soil, but then you avoid the excavation. I find the 35-165 quite good: modify it a bit, then it could still be a nice house for 5 people.

Most captured SPs are not permissible.

On mini-plots, usually yes, though.
Meanwhile, the driveways are regulated along a single line.

There is a floor plan with a technical room; I would rotate (and mirror) the house so that the entrance is in the east, the then northern window in the study would be omitted, and there a small carport next to the trash bin area. The nice living-dining area would still have a south-west orientation.

I wouldn’t mirror anything. Everything is where it should be. Swap the technical room with the office and that’s fine. Kitchen at the terrace, TV/sofa can go to the north.
With 3 kids, though, I wouldn’t neglect the yard, at least for the vehicle fleet etc. My shed is trapped, but it could also serve as a seating shield in the east bottom of the plan… or carport and shed even further to the left of the plan.

What does an ideal building plot look like? Ground level to the street or just a slight depression? Does a basement almost make sense with that depth? Concrete slab + possibly QNG insulation + compacted gravel layer would be how high/deep? Hmm.

For the substructure it may be neutral, but around it embankment will be necessary.

Despite a knee wall of 1.20m quite a lot of slope (the houses further east in the construction area have 6.5m ridge height, we have 4.5m

I consider exemption in moderation to be promising here and recommend, by the way, my post "How the knee wall influences the window question in the attic".