Ok, so maybe I didn't sell the idea of the room for rent well enough.
Here's some more details:
The room is 12ft by 10.5ft, plus a 7 foot wide closet. In the rental costs are all utilities (except for phone and internet access if you want them).
It is in a quiet neighborhood near Rt 28, Rt 29 and Rt 66 (all within 2 miles of the house. And a metro bus runs M-F in the morning and evening to the Vienna Metro stop.
Let me know if you have any questions. PM me or email me.