You will consider the second home to be part personal, part rental. On the screen shot below, you will see "I rent out part of my home". Select that.
You
must divide the expense between rental use and personal use. You can use any
reasonable method for dividing the expense. It may be reasonable to divide the
cost of some items (for example, water) based on the number of people using
them. The two most common methods for dividing an expense are (1) the number of
rooms in your home, and (2) the square footage of your home.
Only
the exclusive used area is considered rental area.
Common
area is available to all and is not a factor in allocation of expenses.
Renting Part of Property
http://www.irs.gov/publications/p527/ch04.html#en_US_2014_publink1000219159
