You would set it up as a rental and then TurboTax will ask if rented at Fair Market Value (FMV) and if it is you can deduct expenses in excess of income and have a loss.
If not and is rented below FMV then the expenses are deductible only to income.
TurboTax will help you in computing this. You will need TurboTax Premier to do this correctly.
Look at the information below:
https://ttlc.intuit.com/replies/4209856
