Did you know that if a vacation house is rented out for less than 15 days each year, the rental income does not have to be reported. According to http://adamash.blogspot.com/2006/11/renting-out-your-second-home-tax.html The IRS apparently gives you a free pass.

For instance if you use a ski condo primarily for own purposes and only rents it out for a week in December.

TAX IMPLICATIONS: This is the most straightforward scenario. If a vacation house is rented out for less than 15 days each year, the rental income does not have to be reported.

While the house can still qualify for the mortgage interest, property tax deductions and write offs for casualty and theft losses, in this tax category, a property owner cannot deduct any other expenses associated with operating and maintaining the house.