Two units, one mortgage, and you live in half of it.
In a market anchored by a large installation, with a steady rental base, this is one of the few plays where the numbers work for a buyer who doesn't have a pile of cash.
But the version of it people repeat online skips the rules that decide whether you actually qualify. Here they are.
Living in it changes the loan
A duplex you live in is a principal residence. A duplex you rent out entirely is an investment property.
Same building. Different loan. Not a close comparison.
Investment property financing asks for more down and prices higher. Owner-occupied doesn't. That gap is the whole reason this strategy exists.
The catch is simple: you have to actually live there, in one of the units, as your primary home.
What you can put down on a two-to-four unit
Conventional: Fannie Mae's Eligibility Matrix allows up to 95% loan-to-value on a fixed-rate purchase of a two-, three-, or four-unit principal residence. That's 5% down.
FHA: HUD states the down payment can be as low as 3.5%, and that FHA is available on one- to four-unit properties.
Neither of those is a typo. You can buy a fourplex with less down than most people put on a single-family house.
Only 75% of the rent counts
This is where the math people run in their head falls apart.
Both Fannie Mae and Freddie Mac take the gross monthly rent and multiply it by 75%. The other 25% is absorbed by vacancy and maintenance before your file is ever underwritten.
So $1,200 in rent doesn't help you by $1,200. It helps you by $900.
Build your plan on the 75% number and you won't be disappointed later.
The appraiser sets the rent figure, not you
On a two-to-four unit, the lender orders Form 1025 — the Small Residential Income Property Appraisal Report, called Form 72 on the Freddie Mac side. The appraiser assigns a fair market rent to each unit.
What the seller says the units rent for is a starting point. What you found searching listings is a starting point. The 1025 is what underwriting uses.
If the appraiser comes in under what you assumed, your qualifying income drops with it.
The rule nobody warns you about
This one gets written about almost nowhere, and it's the first thing I'd check.
Fannie Mae limits how much subject-property rental income you can use based on two things: whether you currently have a housing payment, and whether you have property management experience.
Housing payment now, and management experience: no restriction.
Housing payment now, no management experience: the rental income used in qualifying may not exceed the PITIA.
No current housing payment: no rental income can be used in qualifying at all.
Read that last line twice. If you're living with family rent-free while you save up — which is a common way people get to a down payment — none of the projected rent helps you qualify, at least not on a Fannie Mae loan.
And management experience is documented, not asserted. Schedule E on your tax return is what establishes it.
All of that is Fannie Mae. Freddie Mac handles the same loan differently.
Under Freddie's Guide section 5306.1, an owner-occupied two-to-four unit gets 75% of the rent counted with no landlord-experience test and no requirement that you already have a housing payment.
Same borrower, same duplex, two different answers. Ask which agency your loan is headed to before you assume you're out.
One more thing, and it catches people: the rent does not shrink your house payment. Your full principal, interest, taxes and insurance stays in the housing expense. Fannie says the qualifying rental income is not netted against the PITIA. Freddie says the monthly housing expense is calculated without the rental income. The rent still moves your debt-to-income ratio, just from the other direction — both agencies add the net rental income to your qualifying income, so it lifts the income side instead of lowering the payment side.
That flips completely if you don't live there. On an investment property the rent is netted against that property's full payment first. If it covers the payment, only the surplus counts as income. If it falls short, the shortfall becomes a monthly liability. Both agencies also apply landlord-experience limits on the investment side that don't exist on the unit you occupy. Same building, different math, entirely because of where you sleep.
FHA's self-sufficiency test on three and four units
FHA adds a requirement conventional doesn't have. It applies only to three- and four-unit properties. Two-unit is exempt.
HUD Handbook 4000.1 requires the building to carry itself. The appraiser's estimate of fair market rent from all units — including the one you plan to live in — gets reduced by the greater of the appraiser's vacancy and maintenance estimate or 25%. What's left is the Net Self-Sufficiency Rental Income.
The full PITI has to fit inside that number.
This test isn't about your income. It's about the building's. A triplex can fail it while you personally qualify just fine, and nothing in the listing tells you in advance.
The limits rise with unit count, and don't change across the river
For 2026, HUD publishes identical FHA limits for Muscogee County, Georgia and Russell County, Alabama, because both sit in the same metro area for loan-limit purposes:
One unit: $541,287
Two units: $693,050
Three units: $837,700
Four units: $1,041,125
Conventional conforming baselines for 2026 run higher: $832,750, $1,066,250, $1,288,800 and $1,601,750 for one through four units.
Two things worth noticing. The ceiling nearly doubles between one unit and four. And unlike property taxes, this number is the same on both sides of the river.
What to have ready before you make an offer
Get pre-approved on the multi-unit specifically, not on a single-family number. The rental income treatment changes what you qualify for, and there's no way to know without running it.
Bring two years of tax returns, including Schedule E if you have any rental history at all. If you have none, say so early — it decides which of those three rows above you land in.
And ask what rent figures the appraiser is likely to support, not the ones in the listing.
At 6.65% — Freddie Mac's 30-year average as of August 20, 2026 — a two-unit with a tenant covering part of the payment looks very different from a single-family house at the same price. That's worth running before you decide it's out of reach.
If you want it run on a specific property, reach out.
Tucker Watson is a mortgage loan officer with CrossCountry Mortgage serving Columbus, Georgia, Phenix City, Alabama, and the surrounding communities. NMLS #2762636.
This article is general information about the mortgage process and is not lending advice, a loan commitment, or an offer to extend credit. Guidelines and loan limits change; confirm current requirements for your specific situation before making an offer.