Publication 527
taxmap/pubs/p527-014.htm#en_us_publink1000219159If you rent part of your property, you must divide certain expenses
between the part of the property used for rental purposes and the part of the
property used for personal purposes, as though you actually had two separate
pieces of property.
You can deduct the expenses related to the part of the property
used for rental purposes, such as home mortgage interest, qualified mortgage
insurance premiums, and real estate taxes, as rental expenses on Schedule E
(Form 1040). You can also deduct as rental expenses a portion of other expenses
that normally are nondeductible personal expenses, such as expenses for
electricity, or painting the outside of the house.
There is no change in the types of expenses deductible for the
personal-use part of your property. Generally, these expenses may be deducted
only if you itemize your deductions on Schedule A.
You cannot deduct any part of the cost of the first phone line
even if your tenants have unlimited use of it.
You do not have to divide the expenses that belong only to the
rental part of your property. For example, if you paint a room that you rent, or
if you pay premiums for liability insurance in connection with renting a room in
your home, your entire cost is a rental expense. If you install a second phone
line strictly for your tenant's use, all of the cost of the second line is
deductible as a rental expense. You can deduct depreciation on the part of the
house used for rental purposes as well as on the furniture and equipment you use
for rental purposes.
taxmap/pubs/p527-014.htm#en_us_publink1000219160If an expense is for both rental use and personal use, such as
mortgage interest or heat for the entire house, 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.
taxmap/pubs/p527-014.htm#en_us_publink1000219161You rent a room in your house. The room is 12 × 15 feet,
or 180 square feet. Your entire house has 1,800 square feet of floor space. You
can deduct as a rental expense 10% of any expense that must be divided between
rental use and personal use. If your heating bill for the year for the entire
house was $600, $60 ($600 × .10) is a rental expense. The balance, $540, is
a personal expense that you cannot deduct.
taxmap/pubs/p527-014.htm#en_us_publink1000219162A common situation is the duplex where you live in one unit and
rent out the other. Certain expenses apply to the entire property, such as
mortgage interest and real estate taxes, and must be split to determine rental
and personal expenses.
taxmap/pubs/p527-014.htm#en_us_publink1000219163You own a duplex and live in one half, renting the other half.
Both units are approximately the same size. Last year, you paid a total of
$10,000 mortgage interest and $2,000 real estate taxes for the entire property.
You can deduct $5,000 mortgage interest and $1,000 real estate taxes on Schedule
E, and if you itemize your deductions, you can deduct the other $5,000 mortgage
interest and $1,000 real estate taxes on Schedule A.