Terrace roof on trapezoidal plot

Definitely a glass roof. What you can't see on the plan is that on the side where the terrace is, a second large window has been added so that there is more light inside. We don't want to lose that again with a roof now.

What you don't see on the plan is that on the side where the terrace is, a second large window has been added,

So, you now have the entire front made of glass? Wow, from inside you're now looking directly at a bunch of furniture. There's nothing to hide behind. I would definitely go for asymmetry with that trapezoid. Covered terrace table, lounge or deck chairs then free. It still won't be easier. Is the terrace already paved?

Is the terrace already laid?

I would also be interested in that, because as far as I know, it also has to maintain the distance.

The question is not entirely clear to me either. The maximum width of the terrace roof corresponds to the maximum between the clearance distances. A terrace does not have to be 100% covered.

Have you read the Baybo carefully?
We built a terrace roof many years ago and also submitted a building application.
Here in Saxony, for example, it is such that no building application is required up to 3m depth, since it is an extension to the house or something similar.
Because we have more than 3m depth, the building application was necessary and the neighbors also had to be informed.
If you only want 3m, it should be checked again, maybe it is similar for you.

Then one more personal experience, in case it is your west side:
Fortunately, we have a fairly unobstructed view towards the west. But this leads to the fact that when the sun is low in the evening, you cannot sit either on the terrace or now at this time of year in the dining area of the living room without being blinded. In the dining area of the living room, the awning on the roof is enough for us, but on the terrace we needed a vertical awning.
Since the west is the weather side, rain and snow also blow quite far in, which for example damages terrace furniture. I can only recommend building the terrace roof deeper than 3m.

If you only want 3m, you might want to read up on that again, maybe it is similar for you.

It is about the 3m to the border that must be observed in Bavaria. A depth of 3m is also no problem there.

I know. The question is whether the 3m distance to the boundary must also be maintained if no building permit/application is required because they are subordinate parts.

I believe no one would think of asking the neighbors if you later add a glass roof as weather protection over the front door, even if this would reduce the 3m distance to the boundary.