House Hacking Tax Benefits You Should Know

How Mixed-Use Property Taxes Work

When you house hack, your property serves two purposes: personal residence and rental investment. The IRS treats these portions differently. The rental portion generates deductible expenses, while the personal-use portion follows standard homeowner tax rules.

The split is based on the percentage of the property used for rental. In a duplex where both units are equal size, the split is 50/50. If you rent one bedroom out of four in a single-family home, roughly 25% of the property is rental use. This percentage determines how much of each expense you can deduct against your rental income.

Deductible Expenses on the Rental Portion

The following expenses are deductible against rental income, proportional to the rental-use percentage of your property.

Mortgage interest. If you pay $12,000 per year in mortgage interest on a 50/50 duplex, $6,000 is deductible as a rental expense on Schedule E. The other $6,000 is deductible on Schedule A as an itemized deduction (subject to standard deduction comparison).

Property taxes. Same proportional split. Half goes to Schedule E as a rental expense, half to Schedule A as a personal deduction (subject to the $10,000 SALT cap).

Insurance. Your entire insurance premium for the rental portion is deductible. On a 50/50 duplex with $2,400 annual insurance, $1,200 goes on Schedule E.

Repairs and maintenance. Any repair specific to the rental unit is 100% deductible. A new water heater in the tenant's unit, repainting the rental unit between tenants, or fixing a broken window in the rental space are all fully deductible expenses. Repairs to shared systems (roof, foundation, shared HVAC) are split by your rental-use percentage.

Utilities. If you pay utilities for the rental portion, those costs are deductible. Separate meters make this straightforward. Shared utilities are split by the rental-use percentage.

Property management fees, advertising costs, legal fees related to the rental, and supplies are all fully deductible against rental income.

Depreciation: The Biggest Tax Benefit

Depreciation is a paper expense that reduces your taxable rental income without costing you any cash. The IRS allows you to depreciate the value of residential rental property (excluding land) over 27.5 years.

Here is how the calculation works on a duplex:

• Purchase price: $320,000
• Land value (from assessment or appraisal, typically 15-25%): $64,000
• Building value: $256,000
• Rental portion (50%): $128,000
• Annual depreciation: $128,000 / 27.5 = $4,654

That $4,654 deduction offsets rental income on your tax return. If your net rental income before depreciation is $6,000, depreciation reduces your taxable rental income to $1,346. At a 22% marginal tax rate, that saves you $1,024 in taxes.

Capital improvements to the rental portion (new roof, HVAC replacement, kitchen renovation) are also depreciated, adding to your annual deduction.

The Passive Loss Rules

Rental income is classified as passive income, and rental losses are passive losses. Generally, passive losses can only offset passive income. However, if your adjusted gross income is under $100,000, you can deduct up to $25,000 in rental losses against your ordinary income (W-2 wages, self-employment income). This benefit phases out between $100,000 and $150,000 AGI.

For many house hackers earning under $100,000, depreciation and other deductions create a paper loss on the rental portion even though the property generates positive cash flow. That paper loss reduces your regular income tax bill.

Record-Keeping Requirements

The IRS requires documentation for all deductions you claim. Maintain records of every rental expense, including receipts, invoices, bank statements, and mileage logs for trips to the hardware store or property. Use accounting software or a simple spreadsheet to track income and expenses by category throughout the year.

Keep records for at least three years after filing (the standard audit window), though seven years is safer. Digital records are acceptable, but make sure they are backed up.

Consult a tax professional familiar with rental property, especially in your first year of house hacking. The cost of a knowledgeable CPA ($300 to $600 for a rental property return) is itself a deductible expense and often pays for itself through deductions you might have missed.

For a complete introduction to house hacking, see What Is House Hacking? The Complete Guide.