House Hacking: Using Rental Income to Offset Your Mortgage

Last updated July 2, 2026

House hacking — purchasing a multi-unit property, living in one unit, and renting the others — is one of the most powerful wealth-building strategies available to first-time investors because it combines the favorable financing terms of an owner-occupant loan with the income and tax benefits of investment property. An FHA loan on a two to four-unit property allows a 3.5 percent down payment with the owner-occupant living in one unit. A $400,000 duplex purchased with $14,000 down produces two units — one for the owner and one for a tenant. If the rental unit generates $1,800 per month and the total mortgage payment is $2,600, the effective housing cost for the owner is $800 per month, dramatically below what a comparable single-family home would cost.

The tax treatment of a house hack is nuanced. The rental portion of the property generates rental income that must be reported, but expenses attributable to the rental unit — mortgage interest, insurance, taxes, maintenance, and depreciation — are deductible in proportion to the rental unit's share of total square footage. If the rental unit represents 50 percent of the property, 50 percent of shared expenses become rental deductions. Depreciation on the rental portion, calculated over 27.5 years on the allocated cost basis, creates a non-cash deduction that often makes the rental income tax-neutral or negative for tax purposes while the property appreciates. After one year of owner-occupancy, the property can be converted entirely to rental use or another unit can be acquired with the same strategy.

Modeling a house hack by calculating the full mortgage payment on the target property, subtracting realistic rental income from the non-owner units, and comparing the resulting net housing cost to renting a comparable primary residence. The difference is the monthly wealth-building subsidy from the rental income. For buyers in expensive markets where homeownership feels unaffordable, a two to four-unit house hack frequently makes ownership viable at a lower effective monthly cost than renting a comparable unit.