Move them up to the floor
Screen: Rooms
What it is
A button in the Delete <room>? box, shown in place of Delete room when the room has sub-rooms. The box lists them under Its sub-rooms.
What to enter
Press it to delete the room.
What it changes
In the app: The main room is deleted. Each sub-room becomes a main room on the same floor, with its own devices. Phones show this after the next Save & Deploy.
In the house: After the next Save & Deploy the hub no longer has the main room or its devices.
If it goes wrong
Deploy history keeps the previous version. If the room changed while the box was open, nothing is removed.