Dear client, I hope you will like the idea as well as the design. My idea was to go back to the architectural drawing that already exists, which was added in the description, the only change is to not close the kitchen and the living room with a door, but to close the partition wall between the kitchen and the living room. Thus, you get a separate kitchen and living room, so that it can be a living/sleeping room as well, you can put a pull-out sofa. If you don't want to change the carpentry, you can just repaint it, for example. black matte color. For the fireplace, I had the idea to put it on both sides when there is already a chimney in between, but you can only put it in the living room and close it at the entrance. If you have any further doubts, I am at your disposal.
P.S. The renderings are just to depict the space, I hope you like it