I’ve just drawn a plan of the down stairs of my house for the electrician. Our 4th bedroom is in the converted garage.
We have a separate sitting room, a huge lounge diner with a 12ftx14ft family room coming off the back of it.
We bought the house specifically for that downstairs bedroom for then 18 year old ds. He can come come and go from the back utility door, he has a loo down there.
I don’t know what you’d need to use that room for if it wasn’t a bedroom, we already have two sitting areas.
I suppose it could make a lovely big office, but Dh works from home two days a week, and he’s built an hidden office in one of the alcoves in the sitting room. There’s more than enough room for everyone else in the kitchen diner and the family room while he’s working.
(Upstairs it’s the bog standard 1930s two double bedroom and a box room).
We bought it as a 4 bed. We’d be mad not to list it as one if we ever sold it.