Not property taxes, no; property taxes are not assessed typically on the use you actually make of real estate, but of what its value is in the market, which reflects the uses it could be put to, as well as location, square footage, features, etc. For example, say someone owns a multi-family dwelling and has bad luck--he can't actually rent any units out. He does not get a property tax break for his failure to rent. Obviously, your income taxes are a function of your income, so if you don't have rental income, to that extent, your income will be lower. You should discuss the situation with a tax attorney; there *may* be some advantage to forming a company (LLC or corporation), having the company own the home (you and your sister own the company), and the two of you then pay rent (even very affordable rent) to the company for staying there--this may allow you to deduct certain expenses (then get the proceeds out from the company); however, definitely discuss it before doing it; you'd want to make sure (1) it actually benefits you and (2) it's fully on the up and up.