You’d have to probably loose the middle of the 3 windows as the wall would probably have to fall between the 2 patio doors - which would then hit that middle window. Also, how would hvac be affected and would that described space be big enough for a bed of any meaningful size? I don’t think it would be a bedroom that would feel private in any way and would be one far away from any bathroom so seems like a not ideal project. If it’s a small office with a Murphy for the occasional guest that can stand a long trek to the toilet then maybe….

If you actually need a third bedroom, moving the living room into the dining room space and converting the old living room to a bedroom makes more sense.

There are some fold-out beds that come in low-cabinets — but they are big and square — and also some futon type beds that are really not all that unattractive, and if you keep the dining room to a simple contemporary style it could work

this also comes in grey with a lime piping

ACME Savilla Adjustable Sofa in Yellow Linen and Oak Finish · More Info

Sealy Carmen Chaise Convertible, Aspen Slate · More Info

Innovation Living Zeal Deluxe Convertible Daybed - 94-740021588-3 · More Info

Flash Furniture Loveseat · More Info

(Sorry — this last one might not be a bed but I have seen leather ones just like this that basically just fold open to lay flat)

Cabinet bed

Nebula Full Cabinet Bed with Mattress in Bark Gray · More Info

PS: My problem with using your dining room as a guest room is that you wouldn’t leave your guests any privacy if you got up earlier in the morning to make breakfast.

I agree with the comment that eyeing the living room as a possible sleeping space makes more sense. But it’s also true that it would be great to find new uses for that excess dining space, especially since the room gets so much light. (Another reason might be a poor guest space.) A library reading area would be my choice, with chaise lounge and/or rocking chair.

However, if you want to stick with the idea of using the dining room, consider moving the dining table out of the center of the room. Put a bench along the wall with some pillows, and put the dining table in front of it. That way you would have a lot more room to open up a convertible sofa, and might night need to move the dining table every time.

Boraam Rasmus Dining Bench With Chestnut Wire-Brush Finish 77315 · More Info

Unless you need this bedroom on a daily business, use the remodeling money to put guests up in a nice B&B or hotel near you for visits. Another option if the bedroom is really needed would br to convert part of the living room to guest room and open a L-shaped kitchen/dining/living area.

Oops, forget what I just posted after I look at layout again. Need more coffee.

Thank you all for your thoughts! Very helpful perspective!

I would make the entire DR the master wing BR/bath. The current LR has room for 6’ dining table, 3’ behind each chair. I would also cut 4’ opening from entry hall into Great Room.

All predicated on being able to remove the Kit/LR wall to make a great room