House hacking is a real estate strategy in which you purchase a property, live in one unit or one portion of it, and rent out the remaining space to offset or eliminate your housing costs. It's one of the most accessible paths into real estate investing because it lets you use owner-occupant financing — the most favorable terms available — rather than investment property financing.
The Basic Idea
In its simplest form, house hacking looks like this: you buy a duplex, move into one unit, and rent out the other. If your mortgage is $2,200/month and the rental unit brings in $1,400/month, your effective housing cost is $800/month — less than many studio apartments in the same area.
The strategy can completely eliminate your housing expense if the rental income is high enough to cover the entire mortgage, taxes, and insurance.
Property Types That Work
Duplexes, triplexes, and quadplexes (2–4 units) are the classic house hack. Properties with up to 4 units qualify for conventional and FHA owner-occupant financing, meaning you can purchase with as little as 3–5% down. Once you have more than 4 units, it's classified as commercial real estate and requires different (more expensive) financing.
Single-family homes with ADUs (accessory dwelling units, also called in-law suites, carriage houses, or granny flats) are another option. You rent out the ADU while living in the main house.
Room rentals in a single-family home: You live in the house and rent individual rooms to roommates. This typically generates more total income than a single tenant, but comes with more management.
The Financial Math
House hacking works because of the gap between what you'd otherwise pay to live somewhere versus what you pay after rental income offsets your mortgage.
Example: You buy a triplex for $420,000 with 5% down ($21,000). You rent out two units at $1,300/month each.
Monthly mortgage (P&I, taxes, insurance): $2,800
Rental income from 2 units: -$2,600
Your effective housing cost: $200/month
Compare that to renting a comparable apartment in the same area for $1,500/month. You're saving $1,300/month — $15,600/year — while simultaneously building equity.
The Owner-Occupant Financing Advantage
The reason house hacking is so financially powerful comes down to financing terms. Owner-occupant mortgages allow:
- 3–5% down payment (vs. 15–25% for investment properties)
- Lower interest rates (typically 0.5–1.0% lower than investment property rates)
- FHA loans (3.5% down, more lenient credit requirements)
- VA loans (0% down for eligible veterans)
On a $400,000 property, the difference between 5% down ($20,000) and 20% down ($80,000) is $60,000 of capital preserved for other investments.
What to Look for in a House Hack Property
Rent-to-price ratio: The total rent from all non-owner units should cover as much of the mortgage as possible. Use the 1% rule as a quick screen — if monthly rent from the rental units is at least 0.5–1% of the purchase price, the numbers likely work.
Separate entrances: Tenants and owner having separate entrances dramatically improves the living arrangement for both.
Local rent demand: Strong rental demand means lower vacancy and market-rate rents. Look for properties near employment centers, universities, or transit.
Condition and capital expenditures: A house hack is only profitable if the property doesn't immediately require major repairs. Factor in the cost of a new roof, HVAC, or electrical update in your analysis.
Tax Implications
When you rent out part of your primary residence, the rental portion is treated as a rental property for tax purposes. You can deduct a proportional share of mortgage interest, property taxes, insurance, repairs, and depreciation against your rental income.
When you eventually sell, the owner-occupied portion qualifies for the principal residence capital gains exclusion ($250,000 single / $500,000 married), but the rental portion does not.
To model your effective housing cost and cash flow for a house hack, use the House Hack Calculator. For a full rental property analysis, use the Rental Cash Flow Calculator.