New construction project single-family house in the Bergisches Städtedreieck

This belongs to the adjacent development plan; so it at most only has an orientational character.

From the excerpt in the initial post, it looks to me as if exclusively the (still undivided) affected property is excluded from its scope. I suspect the reason is that the planning area is supposed to be a WA, and the affected property had an MI or GE use, so this trick was chosen. In this sense, I "read" as the intention of the area development not to deal with the affected property differently in the future than with the area by which it is surrounded. Therefore, the orientational character seems to me to have a defining scent here. One should perhaps suggest merging this §34 property into the surrounding development plan.

Use template 0.3/0.8
What exactly do these numbers mean?

A plot ratio of 0.3 means that 0.3 times the plot area may be built upon; a floor space index of 0.8 means that 0.8 times the plot area may be created as "living space." 0.8 divided by 0.3 is more than 2.0 — I read this as an indication that further habitable rooms can be created in the attic on the second full floor.

Thanks!

I read that as a hint that additional living rooms could be created on the second full floor in the attic.

Does that mean that in the attic - for example - another children's room or a storage room could be created?
But for that, a gable roof would have to be put on, right?

whether a MI or GE use was present

Yes, it was a commercial use.

It looks to me in the excerpt in the original post as if exclusively the (still undivided) affected property is excluded from its area of application.

Yes, it looks like that. But it is not. That is the problem with edited, incomplete, or too limited "construction documents" submitted to the forum. But then we are back to the discussion from the house pictures thread.

Does that mean that an additional children's room or even a storage room could be created in the attic?

Living space, yes. Storage space doesn't count at all, you can always make the attic storage.

But for that, you'd need a gable roof on top, right?

It also works with hipped or shed roofs. If necessary, even with a recessed story if you're a flat roof enthusiast.

Yes, it looks like that. But it isn't.

Too bad.

That's the problem with processed, incomplete, or too restricted "construction templates" submitted to the forum.

Yes, always this zoom on the tiny detail :-(