Well, the southern sun will have to suffice. You definitely don’t have west sun on the sofa. But you have to die some kind of death. If the neighbor definitely extends the 9m maximum to the back, it’s worth considering whether to let in the east sun instead. Ideally into the kitchen – but I’m not going to start on that again.
The large window front facing east in the living room is questionable, though. Nobody lounges on the sofa at 6 a.m. You’d have to have regular fights in the marital bed to have someone move out. Otherwise, there’s no one there at that time.
Well, these are questions better asked at the BEGINNING of planning. Then you’d quickly come to the conclusion that it would be quite attractive to place all living spaces on the south side and rather build something like 11.5 x 9 m.