What I don’t quite understand: you only have 3-5 guests a year, but you reserve them a huge room. What happens to the room otherwise? I would combine the work and guest areas there and thus gain enough space upstairs to have a sensible dressing room (the current cramped dressing rooms are not), possibly also set up a small utility room there and let light into the hallway in an architecturally beautiful way. The long corridor it has now is just wasted space and also looks sh... Then rather a skylight instead of this corridor. With only one child, you can also consider whether to give the child’s room a few more square meters and make a small room retreat with a separate sleeping area – then maybe keep the teenager a bit longer at the mother’s breast. Or a small, separate bathroom. After the teenager weaned from the mother’s breast moves out, this can be well used as a guest area without having guests in the private bathroom, and the work area remains downstairs.