What's the catch with buying a house with an ADU or a duplex to live in?
There is no hidden one. It is a home loan, and it asks three things of you. You live in the home. You are the landlord for the other unit. You still pay for housing, because the rent covers part of the payment and not all of it.
WHAT MOST PEOPLE ARE NEVER TOLD
The loan's conditions are written down and public. That means a home can be checked against them before you make an offer.
Here is how the loan works:
- You move in within 60 days of closing and live there at least a year.
- The lender counts up to 75 percent of the other unit's rent, once you meet its conditions.
- You may need savings left after closing. On a conventional loan, Fannie Mae's automated system asks for six months of payments on a two-to-four unit home you live in. On a one-unit home it sets no minimum.
You are also the landlord, and you live on the same lot. You find the tenant, answer the phone when the water heater quits, and share a wall or a yard with the person paying you. Rental and fair housing law set the rules for that part.
A lender looks at your debts against the income it counts, and at the home itself. So have the home checked first: its leases, its legal unit count, and the rent an appraiser is likely to write down.
GOOD TO KNOW
Before you start, be sure you want to live that close to the person who pays you rent. Then look at a listing, which shows the monthly cost with the rent and without it. If covering the whole payment alone for two months would be too tight today, save first, and ask us what gets you there.
Yours is a little different. They all are.
Tell us what you are looking at and what you are trying to do. We answer with the numbers on your situation.
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WHERE THIS COMES FROM
- Fannie Mae Selling Guide B2-1.1-01, Occupancy Types
- Fannie Mae Selling Guide B3-3.8-02, Rental Income from the Subject Property
- Fannie Mae Selling Guide B3-4.1-01, Minimum Reserve Requirements
- HUD Handbook 4000.1 (FHA): II.A.1.b.iii occupancy, II.A.4.c.xii rental income, II.A.4.d.i(C) reserves
- Series Homes analysis of 2025 HMDA data (FFIEC): home-purchase applications on two-to-four unit properties. Denial rate is denied divided by originated, approved but not accepted, and denied. Reasons are the denial reason codes lenders reported.
- HUD, Housing Discrimination Under the Fair Housing Act
Researched and written by Series Homes. Checked against its sources on . Lending rules change. This page is general information, not a loan offer or legal or tax advice.