If I put in zero, however, it does not appropriately portion out the expenses - it tries to portion the full 30% of mortgage interest, for example. Every tax guidance I have read states that expenses such as property taxes need to be multiplied by BOTH the portion of the house classified as a rental (30%) AND the proportion of days in the year it is actually occupied (44/366). It is this calculation that TurboTax is not allowing me to do.
