Floor plan design of a 9x13m gable roof house with an attached 6x9m attic

The experienced planner derives the ground floor from the upper floor, which I regularly point out. How much freedom you have on the upper floor can be influenced, among other things, by the choice of the floor ceiling there. See also "The upper floor has priority" and "Lightweight walls in solid houses?".

Thanks,
Do you perhaps have a link to the mentioned posts or can you tell me where and how I can find them?

I am also not 100% sure if I understand what you meant.

Without having read the posts, I would like to point out that - if on the ground floor windows are only available on one side (in an extension or, as here, a long garage) and also the southwest orientation of the house basically dictates the location of the living/dining area - it is difficult to derive the ground floor layout from the upper floor (with depending on the knee wall height possible windows on both long sides).
That there are constraints on the upper floor regarding room layout and position of sanitary installations because of the roof slopes is clear.

Maybe you can explain to me in more detail what exactly you mean here.
Thanks

For the average family, the necessities initially arise in the upper floor. There need to be 2 or 3 children's rooms, a bathroom, a bedroom, an attic hatch, possibly an office. That's why you plan that first. This already results in quite a bit on the ground floor, because the utility room and guest toilet ideally lie under the bathroom on the upper floor, for example.

It's annoying when you start downstairs and then have to either squeeze upstairs or have huge ballrooms in the bathroom and bedroom. But if you’re planning 180m² for 2 people, it probably doesn’t matter in the end. That is generally completely exaggerated and hardly maintained and kept up in older age.

I have great understanding that a construction project must fit according to Para 34, but I have less understanding that there apparently are no clear and outwardly transparent criteria within which one can create a plan that then also has validity.

There are no clear criteria in Para 34, and there is also no plan. Otherwise, there would essentially be a development plan.

If there are freshly built houses still standing in the same district,

Same district is not the same as neighboring buildings. You cannot refer to an entire village or district or whatever when Para 34 concerns the neighboring buildings.
It is just the way it is: whoever buys a plot should get informed.
And as far as I understand, you did get your gable side approved including a huge double garage, which does not really fit in old residential streets. So in that respect, you can be satisfied with the result, right?!
If you want to build on another plot, then send an architect who represents your interests in front of the building regulation office people who know him. That saves effort and is usually somewhat more successful.

Do the two ground floor layout proposals make sense in terms of room sizes, room divisions, and corridor widths?

What about the upper floor?
Since you (or you all) plan to initially have the sleeping floor in the upper floor, I would use the planned dressing room here as a wardrobe.
If later you can’t manage anymore and move downstairs or stay on top due to being bedridden, you won’t need a large wardrobe anymore. That can all go into the utility room then.
I don’t like the straight corridor because from the entrance or door you can already look directly into the private area. The idea actually comes from me, but personally, I would fiddle with it until it fits. If you take the draft to a company, nobody will help you there and they will build everything, including faux pas.
Then I also have to say that with all the limitations and wishes, why and how the house should now not be built one meter longer, I get confused. There is no sketch that shows a supposed “building line” or “building boundary.” Because if you must build the house three meters from the street but the garage five meters, you can very well plan the entrance on the side. I have never understood why one now has to get through a direct door into the garage and avoids the path across the front door.
I actually had to flip forward again because no north is marked.
And the garage is not visible either. I would always include everything, including parking spaces etc., in a draft. You can get a good but different approach that quickly but then forget the other components of the planning.
Draw the entire plot to scale, mark the limitations, then place the house and the garage on it and communicate that.
And therefore I cannot answer this question at all…

What potential advantages would arise from your point of view if the house or garage could still be shifted against each other in the longitudinal direction by 1 to max 2 meters?

Was there ever the drawn plot including all components, except the subsequently submitted site plan from ?

What about the upper floor And the garage is also not visible. I would always include everything, including parking spaces, etc., in a draft. You can quickly get a good but different angle, but then forget the other components of the planning. Draw the entire property to scale, mark the limitations, then put the house and garage on it and convey it. And that is why I cannot answer this question at all. Was there ever a drawn property including all components, except the subsequently submitted site plan from ?

Thanks for the hint. You are certainly right. I will upload a top view where you can see the property, garage, and house. The upper floor will be added then as well.

Here is the overall view.

The zero line in the y direction is the property boundary with the directly adjacent sidewalk. The outlines of the property (please no comments regarding the "border planting" and the "equipment" of the garage...) are, I hope, recognizable.
On the property, there is still a cooling room on the southwest property boundary, which is to be converted into the garden house.
The horizontal wall at the top of the sketch is the house wall/fire wall of the existing building.
The property already opens up a bit in the front area and then widens significantly at about 17m on the x-axis.

and for the sake of completeness, the upper floor