You can record in the box you have.
You could by another and put it in another room, record on one and watch the other.
Then swap the HDD between boxes as you need it.
Same as a twin tuner but you have a box in each room.
If you get a server who supplies multiroom you pay for one line and can run two boxes.
Or,
Buy a twin tuner box, something like a Vu+ Solo 2 or Vu+ Duo, you get extra bells and whistles going down this route
but it is more expensive. This would probably be closer to Sky +