Switch to the 2D plane view, select the room and change the room type in the "Room Type - Current Type" on the right side. Once you have finished modifying the room type, you can also manually enter the name for the room in the box on the right.
Switch to the 2D plane view, select the room and change the room type in the "Room Type - Current Type" on the right side. Once you have finished modifying the room type, you can also manually enter the name for the room in the box on the right.