House with room mates and tax deductions

[Jeff D.]

Hi All, 

I finally bit the bullet and bought a house which will serve as my primary residence. Instead of a fixer, I ended up with something done which I hope to hold onto for 5-7 years while property values in Austin continue to rise. 

I have a room mate who will move in and pay rent. He will also watch the property for me/ help maintain it while I travel (often for weeks at a time). 

The question I have what expenses (utilities, maintenance, updates, etc) can I deduct if I have a room mate and what portion of the total expenses can I deduct? 

Room mate will have his own room, but will have equal use of all other rooms (ex the master) in the house. 

Does this mean I can deduct 50% of all expenses? 

Thanks in advance for your help. 

-Jeff