Gladly, I had already tried, but maybe some information is still missing:
Is there a development plan and/or parking space statute of the municipality?
There is a supplementary statute that regulates the development, but regarding parking spaces it only states that paths, parking spaces, and driveways need to have a water- and air-permeable structure. Further down, where permissible roof design is addressed, garages, carports, and outbuildings are listed as exceptions to the provisions concerning roof shape. As far as I can tell, there are no further regulations, but if necessary I would try calling the municipality again. The statute applies specifically to our street section.
Is there a planned driveway on the street, which is 3 m away from the property, in the northeast?
Yes, the one in the northeast is a driveway. This is explained by the fact that in 2025 a pedestrian path will be built along the street, and driveways to the properties will also be created. Two properties always "share" 6 meters of driveway, whereby, depending on the property orientation, one is always located either on the right or left at the "corner" of the property.
I would first think about where the house will be placed.
Our orientation was like this: We build as close to the street as possible, to the "right" of the house (on the property sketch, so facing north) where the driveway is, the cars/carport/garage are to be positioned prospectively at the edge of the property, adjacent to that the house, so that we have distance to the next property to the west (or left in the sketch). Of course, we also have to keep at least 3 meters to the street, but maybe somewhat more distance so that cars can maneuver well or if necessary there is also space for visitors to park on the property.
Alternatively, one could consider planning the parking spaces on the street side in front of the house, but then you always have to drive out awkwardly around the corner because the driveways are planned right at the edge of the property.