Room divider - one-sided or double-sided?

how wide is it from the fireplace to the opposite wall?

I'm on the go, my son just measured it, it should be 4.87m = 2.80 for the wall and about 1m width on each side? (hope he measured it correctly )

and consider something regarding the spark protection around the fireplace. Don't want you to block the passage with a trip hazard (laid glass plate).

I'm getting tiles everywhere on the ground floor, do I still need a glass plate?

No, tiles are completely sufficient

1m passage on each side would be sufficient for me.

I would definitely go for the double-sided version, but maybe have a correspondingly high Ytong wall or something similar built. I don't know exactly how you want to execute it, but if you want such an airy solution, you have to think a lot about cables, possibly TV furniture, etc., and it will probably never be as solid as a masonry wall, especially because someone is supposed to sit on the other side. You don't know for sure yet if there will actually be a fireplace exactly there, right? If yes, you should carefully try out the distances to see what feels comfortable for YOU. I understand the disturbance caused by movement, so rather a solid wall maybe 140cm high, which you can design as you like on the other side. Maybe this wall needs a small 90-degree bend on the side for stability; then your TV area would be framed on the side and still open to the top and both sides. We built something similar in our bedroom. I am currently reading that you want to keep the wall flexible... but due to cables, connections, sofa, etc., you won't be able to be flexible, and why would you want to?

I am currently reading that you want to keep the wall flexible..... but due to cables, connections, sofa, etc., you will not be able to be flexible, why would you?

I have also had connections for satellite and so on installed on the wall side; maybe one day the partition wall can be removed again and the dining area as well, the dining area could then be next to the kitchen island, there is still a corner there.

Would a aerated concrete wall be significantly more stable?

Whether it will actually and exactly be a chimney there, you don't know for sure yet, do you?

Yes, it will come .... I had the chimney installed specifically for this.