Maybe -- but it depends on the total number of rooms (not just bedrooms) you have in the house. Assuming you have a total of 6 rooms: the three bedrooms, one bathroom, a kitchen, and a living/dining room area, then you can take 100% of the two rented rooms and 2/3 of each of the shared rooms. So that is:
2 (rented rooms) + 2/3 of 3 rooms = 4/6, or 2/3 (67%).
If, however, you have 2 bathrooms and one is just for you, then you have 7 rooms, but can still only add 2/3 of the three shared rooms:
2 (rented rooms) + 2/3 of 3 rooms = 4/7 = 57%.
You can, however, probably deduct 2/3 of utility costs if you are all around roughly the same amount of time.
