Can one room be a home office and a guest room?
Yes — a fold-down wall bed hides in a cabinet about 45 cm deep and leaves the room free for a desk the rest of the time.
Yes — a fold-down wall bed hides in a cabinet about 45 cm deep and leaves the room free for a desk the rest of the time.

Short answer: yes. A fold-down wall bed (often called a Murphy bed) hides in a cabinet roughly 40–45 cm deep, so the room works as a full study every day and turns into a guest room in a minute.
When a double wall bed is down it needs about 210–220 cm of clear floor from the wall. Keep that zone free of the desk and chair, or choose a model with a built-in shelf or desk that folds with the bed.
Put the desk at a right angle to the window. Facing the window causes glare on screens; sitting with your back to it puts your screen in reflection and your face in shadow on video calls.
Plan closed storage for work files and a free shelf or a few hangers for guests, so neither use takes over the room. Add a socket beside the bed and a reading light for visitors.
In our Dino Kids' Room & Home Office project, the wall bed sits inside a run of panelled wardrobes, so when it is closed the room looks like a calm wood-and-grey office.