Terraced house on a 240 sqm plot - fundamental questions / feasible?

Often, green roofs are welcomed by the cities,

Except with hemp *just kidding* - unfortunately, it is often not welcomed from the heart, but every municipal council faction wants to play the garden gnome uniform command again and lists from the botany lexicon exactly what should go there and what not in leap years, similar to roof tiles only in RAL 4711

and lists from the botany lexicon exactly what is supposed to go there and what not in leap years, similar to the roof tiles only in RAL 4711

Seriously? Well, there aren't really any ugly plants, are there?

Well, there are actually no ugly plants, right?

It is enough if the members of the town council bear a frightening resemblance to their garden gnomes.

So, the feedback from the city planning office is in, unfortunately negative. I find it somewhat puzzling that the development plan explicitly states something first ("4m garage height possible," "roof terrace possible"), which is then overridden by other regulations. Then one might as well save the wording that the garage may be 4m high or that the creation of roof terraces is permissible...?

Garage height
The development plan allows a maximum garage height of 4m on this building plot. However, since the garage is located outside the buildable area of the property and thus is not directly affected by the deviating construction method, the setback regulations of §6 state building code must be observed. Accordingly, the height of the garage may be a maximum of 3m and the wall area at the property boundary a maximum of 25m².

and

Roof terrace
The deviating construction method allows roof terraces on the garage. According to Ms. xxx (construction expert), fundamental building regulation issues need to be clarified, which may oppose approval. We therefore recommend assuming when making the purchase decision that a roof terrace on the garage may not be approvable.

Who comes up with such things, is that meant only to cause confusion or did the drafters of the development plan not understand it themselves?

I am not a lawyer, but depending on how important the rooftop terrace is to you, I would seek specialized legal advice.

Da sich die Garage aber außerhalb der überbaubaubaren Grundstücksfläche befindet und somit nicht unmittelbar von der abweichenden Bauweise betroffen ist

Is IMHO nonsense. I don’t have time right now, but I’m interested. I will read the commentary when I get the chance to see if I’m wrong. I have always understood the law to mean that planning law can override building regulations. In particular, §5 (1) sentence 3 of the state building code confirms this. And the development plan is clear here.
Does no neighbor have a rooftop terrace?
Are both quotes from the city planning office?
How many plots are still free?

It probably won’t be enough for extra3, but the local press might be interested in something like this.

Hello , I saw that you have an overhang at the entrance area and thus a canopy. I am currently planning something similar myself. Can you share your experience regarding the costs since it certainly had to be reinforced and insulated extra.. thanks in advance