Boundary construction garden shed NRW

Our neighbor has agreed to the deviation. Is that what you mean?

Yes. So no building encumbrance. Although the full 10.70m counts, since the boundary to the public green area is not added, it works out.

So from your point of view no problem building the hut like that?

Yes, as long as it is a public green area. The picture shows an "ö", but since I don't know if that's a section of the current legally binding original plan and whether the "ö" might stand for something else, you should clarify that.

Before I tear down a small house for 2-3K EUR again, I just inquire

Just do that. It can't hurt, as long as you built as approved. It would be a shame if it turns out in the end your terrace was not built in accordance with the development plan and/or the floor area ratio is exceeded.

Thank you for your assessment. It should actually all be in accordance with the development plan, but just to be safe...