The pitch has not changed since this article first ran: buy a property with a rental unit in it, live in one part, and let a tenant’s rent pay part of your mortgage. What has changed is the arithmetic around it. With the 30-year fixed in the mid-6s and the median existing home around $429,300, a $400,000 loan at 6.5% costs about $2,528 a month in principal and interest. Rent that covers a third or half of that is the difference between a stretch and a comfortable payment, which is why “house hacking” has gone from a niche idea to a mainstream one. Here is how it works under 2026 lending rules, and the questions to ask before you count on someone else’s check.

Three ways to do it

  • A two- to four-unit home you occupy. Duplexes, triplexes and fourplexes qualify for owner-occupied financing as long as you live in one unit. This is the version lenders understand best.
  • A home with an accessory dwelling unit. A finished basement apartment, a garage conversion or a backyard cottage with its own entrance and kitchen. ADU income now has explicit rules at both FHA and Fannie Mae.
  • A roommate. The simplest version, and the one lenders count least: boarder income is generally not accepted for conventional qualifying, with an exception for Fannie Mae’s HomeReady program, where it is capped at 30% of your total income and needs 12 months of documented shared residency and payments.

Financing an owner-occupied multi-unit

Two programs do most of the work. FHA requires a minimum investment of 3.5% of the property’s value on owner-occupied one- to four-unit purchases, with a 580 credit score, which makes it the cheapest way into a fourplex. On the conventional side, Fannie Mae has allowed 5% down on owner-occupied two- to four-unit purchases since late 2023, where it used to require far more; lenders commonly offer it on conforming loans that are not high-balance. Check the 2026 loan limits for your county before you assume a multi-unit price fits either box.

The strings attached are where first-time landlords get surprised:

  • Your own cash. On a conventional two- to four-unit purchase with less than 20% down, at least 5% must come from your own funds; gift money can top it up but cannot replace it.
  • Reserves. Conventional loans require no minimum reserves on a one-unit home but six months of the full payment (principal, interest, taxes, insurance and association dues) in reserve on a two- to four-unit primary residence. FHA requires three months of the payment in reserve on three- and four-unit properties.
  • FHA’s self-sufficiency test on three- and four-unit properties. The property has to carry itself on paper: the full monthly payment cannot exceed the appraiser’s estimate of market rent for all the units minus a vacancy and maintenance allowance of at least 25%. A fourplex whose rents do not clear its own payment will not get an FHA loan no matter what you earn.

How lenders count the rent

Nobody counts 100% of the rent. Fannie Mae reduces appraised rent by 25% for vacancy and maintenance, and FHA does the same when there is no rental history, so a lender counts 75 cents of every dollar of market rent. That figure comes from the appraiser’s rent schedule or the leases, not from a listing you found online.

The rules that decide whether the remaining 75% actually helps you qualify:

  • Only the units you do not live in count. On a Fannie Mae loan for a two- to four-unit primary residence, your own unit produces no rental income on the application.
  • Fannie Mae wants a landlord track record. Lenders may count net positive rental income, meaning rent above the property’s own payment, only if the borrower has at least 12 months of property-management experience. The exception is ADU or boarder income on a one-unit primary residence. If you have never been a landlord, ask the lender exactly how the rent will be treated before you shop.
  • ADU income is capped at 30%. At Fannie Mae, rental income is allowed from one existing ADU, on purchase or limited cash-out refinance transactions only, and cannot exceed 30% of total qualifying income. FHA applies the same 30% cap to ADU income.
  • FHA and rental history. With no rental history, FHA counts 75% of the lesser of the appraiser’s market rent or the actual lease. With a history, it wants 24 months of it, with no unexplained gaps longer than three months.

Landlord basics before you close

The income is real only if the operation is. Screen every applicant against the same written criteria and apply them the same way to everyone; fair-housing rules are federal, and local rules add to them. Use a written lease. Tell your insurer that a unit is rented, because a policy written for an owner-occupied single-family home may not cover a tenant’s unit or your liability as a landlord, and ask what changes. Check the local rules before you buy: zoning, rental registration, ADU permitting and security-deposit limits all vary by city and state, and an unpermitted basement apartment can be ordered vacant. None of this is hard, but none of it is passive.

The four questions that still decide it

The reality check this article has always ended with holds up in 2026, with sharper numbers behind it.

  • Do you have a real emergency fund? When the tenant’s water heater fails, it is your water heater. The six-month reserve a conventional lender requires on a multi-unit is a floor, not a target, and the CFPB’s own guidance is that the right amount depends on your situation.
  • Can you carry the whole payment alone? The lender assumes 25% of the rent will not show up. Assume the same, and run your budget on the full payment for the months between tenants.
  • Do you want someone else living in your building? A shared wall, a shared driveway and a shared water bill are part of the deal.
  • Can you handle the hassle? Late rent, a pet that was not in the lease, a call in the middle of the night. The rent is compensation for that work, not a gift.

If the answers are yes, house hacking is one of the few levers that genuinely moves the affordability math at 2026 rates. Start by working out what you can carry on your income alone with how much house you can handle, then let the rent be the margin, not the plan.