House hacking with duplexes, triplexes, and fourplexes

What house hacking is, and why it works

House hacking means buying a multifamily property with one to four units, living in one unit, and renting the rest. The rent from tenants reduces or eliminates your housing payment, while you gain rental property ownership, depreciation, and principal paydown. Lenders and tax rules treat 1 to 4 unit properties as residential, which opens owner-occupant financing paths like FHA loans with low down payment requirements.

The FHA angle: the basics you must know

• FHA loans allow purchase of 1 to 4 units with a minimum down payment often as low as 3.5 percent, provided you occupy one unit as your primary residence. You must move in within a short window after closing, and lenders typically expect you to live there for at least 12 months. Check specific lender and FHA guidance for exact timing.
• FHA loan limits vary by county and by number of units, so always verify local limits before searching. Condos and planned developments require additional FHA approval.
• FHA requires mortgage insurance, which increases your monthly payment. For worked examples below I will include a hypothetical annual mortgage insurance premium to illustrate the impact. Treat those numbers as examples to adjust for your actual loan terms.

How to think about numbers, and the math you need

Key monthly line items to track: principal and interest, mortgage insurance if FHA, property taxes, homeowners insurance, maintenance and reserves, utilities you pay, and vacancy or management costs. Compare total monthly ownership costs to rental income from tenant units. A simple cash flow formula is:

Total monthly costs minus tenant rent equals your out-of-pocket housing cost.

If that number is zero or negative, you are effectively living for free or with positive cash flow.

Worked examples, with clear assumptions

Common assumptions used across examples: 30-year fixed mortgage, 6.0 percent interest, and an assumed FHA annual mortgage insurance premium of 0.85 percent for calculation purposes only. Down payment 3.5 percent. Monthly P&I is computed using standard amortization, shown rounded.

Duplex example

Say a duplex lists at $320,000.

• Down payment 3.5 percent: $11,200.
• Loan amount: $308,800.
• Estimated P&I at 6.0 percent: about $1,851 per month.
• Add FHA annual MIP of 0.85 percent, monthly: about $219.
• Property taxes: $350 per month. Insurance: $100. Maintenance/reserves: $150.
• Total monthly ownership cost: $2,670.

If the rented unit brings $1,500 per month, tenant rent covers part of the cost, leaving your out-of-pocket housing cost at $1,170 per month. A duplex often reduces rent burden but may not remove it completely unless rents are higher or purchase price is lower.

Triplex example

Say a triplex lists at $420,000.

• Down payment 3.5 percent: $14,700.
• Loan amount: $405,300.
• Estimated P&I at 6.0 percent: about $2,430 per month.
• FHA annual MIP 0.85 percent, monthly: about $287.
• Taxes $450, insurance $130, maintenance $200.
• Total monthly cost: $3,497.

If two rented units pull $1,600 each, tenant income is $3,200. With you living in the third unit, your out-of-pocket cost falls to about $297 per month. If the two rents are $1,750 each, tenants cover the entire monthly cost, putting you at neutral or slightly positive cash flow.

Fourplex example

Say a fourplex lists at $560,000.

• Down payment 3.5 percent: $19,600.
• Loan amount: $540,400.
• Estimated P&I at 6.0 percent: about $3,240 per month.
• FHA annual MIP 0.85 percent, monthly: about $383.
• Taxes $600, insurance $180, maintenance $300.
• Total monthly cost: $4,703.

If three rented units bring $1,600 each, tenant income is $4,800. With you in one unit, tenant rents exceed costs by about $97 per month, meaning you effectively live free and have a modest positive cash flow. Lower rents will reduce that surplus.

Practical considerations beyond the math

• Utilities and who pays them matter. If you pay heat or water for multiple units, add those costs.
• Vacancy and turnover: budget at least one month of income per year as a vacancy reserve, or a percentage like 5 to 10 percent of gross rent.
• Property management: self-manage to maximize savings, or hire a manager at 8 to 10 percent of rent if you prefer a hands-off approach.
• Maintenance and unexpected repairs: set aside a dedicated sinking fund.
• Taxes and depreciation: rental expenses, mortgage interest, and depreciation reduce taxable income, consult a CPA for details.

A concise action checklist

1. Verify FHA loan limits and owner-occupancy rules with your lender for the target county.
2. Run net cash flow calculations using realistic rents, taxes, insurance, and MIP. Plug your numbers into a rental cash flow tool to speed this step, like the DealBumble rental cash flow calculator at /tools/rental-cash-flow-calculator.
3. Confirm unit condition and repair needs, budget for rehab or inspection issues.
4. Run comps for rent levels and estimate conservative vacancy and maintenance reserves.
5. Close and move in, then manage the property to stabilize rent and occupancy.

House hacking is a leverage strategy, not a get-rich-quick scheme. Proper underwriting, conservative rent assumptions, and realistic repair budgets are the keys to success.

Run the numbers on a property you can comfortably afford, adjust for your market, and you may find living for free or nearly free is realistic with a duplex, triplex, or fourplex.