Does ADU Rental Income Count Toward Your Mortgage in Atlanta?
On September 2, 2026, Fannie Mae restructured its rental income requirements and moved its accessory dwelling unit guidance into its own section of the Selling Guide. The rules are encouraged now and become mandatory for loans with application dates on or after November 1, 2026.
This is worth understanding before you assume it is bigger news than it is. Fannie Mae first opened the door to ADU rental income in October 2025. What the September 2026 update does is spell out the calculation in more detail, including how much of the rent a lender starts with and how a borrower's landlord experience affects whether that rent helps at all.
So rental income from an existing ADU may help some buyers qualify. That does not mean the rent from every basement apartment, garage conversion, or backyard cottage will count. The property, the rental documentation, the loan program, and the borrower all have to meet specific requirements.
The Short Answer
Rental income from an existing ADU may be considered when a buyer is purchasing a one-unit primary residence, the unit qualifies as an ADU under the applicable loan program, and the rent is supported by the required appraisal documentation. Even then, only a portion of the rent is considered, and there is a cap on how much of it can help.
Whether it helps a particular buyer is a lender decision, not something you or I can determine from a listing photo.
When Fannie Mae May Allow ADU Rental Income
Under the current Selling Guide, ADU rental income may be considered when all of the following apply:
The property is a one-unit primary residence with one existing ADU.
The transaction is a purchase or a limited cash-out refinance.
Rental income is considered from only one ADU.
For a purchase, the lender obtains an appraisal with a Single-Family Comparable Rent Schedule (Form 1007), or a Small Residential Income Property Appraisal Report (Form 1025) where applicable.
If an existing lease is being transferred to the buyer, the lender also obtains the fully executed lease, and the rent has to be supported by the appraisal.
The qualifying rental income from the ADU does not exceed 30% of the borrower's total qualifying income.
That last one surprises people. Even when everything else lines up, the ADU can only carry so much of the qualification.
How the Lender Calculates and Applies the Rent
The lender does not simply add the rent to a buyer's income. The calculation runs in steps.
First, the lender takes 75% of the supported monthly gross rent. That reduction accounts for expenses and potential vacancy. Then the lender subtracts the property's PITIA, meaning principal, interest, taxes, insurance, and any applicable association dues, to arrive at what Fannie Mae calls adjusted net rental income.
What happens next depends on the borrower.
If the borrower has at least 12 months of rental property management experience, positive adjusted net rental income may be used in qualifying, subject to the full guidelines. If the borrower has less than 12 months of that experience, positive rental income may generally be used only to offset the property's PITIA rather than to add income. In either case, negative adjusted net rental income is included in the debt-to-income ratio.
An illustration, not a loan quote: if the supported market rent is $1,500 per month, the lender may begin with 75% of that, or $1,125. The lender then subtracts the property's PITIA from the $1,125. How the result affects qualification depends on the borrower's rental management experience, the 30% income cap, the loan program, and the lender's underwriting findings. Your own numbers will differ.
Fannie Mae Is Not the Only Path, and the Programs Are Not Interchangeable
FHA has its own ADU rules, and they are not a copy of Fannie Mae's.
Under HUD Mortgagee Letter 2023-17, rental income from an ADU may be considered effective income on a one-unit property with an ADU. Where the borrower has no rental history, FHA looks at 75% of the lesser of the appraiser's fair market rent or the rent in the lease, with a lower percentage applied on 203(k) rehabilitation loans. FHA also caps ADU rental income at 30% of total monthly effective income and does not allow it on a cash-out refinance. The appraiser has to address whether the ADU comports with zoning, which may include a legal nonconforming use, and whether it can be legally rented without restrictions.
Freddie Mac has its own requirements as well, including its own documentation standards for comparable rentals and a stated position that rental income from an illegal ADU may not be used to qualify.
The practical takeaway is that the loan program matters as much as the property. Anyone counting on ADU rent should talk to a lender who works with that specific program before relying on projected rent.
Why Permits, Zoning, and Appraisal Findings Still Matter
I would avoid the shorthand that a permitted ADU always qualifies and an unpermitted one never does. The real answer is more particular than that.
The lender and the appraiser determine whether a space qualifies as an ADU under the applicable loan program. Zoning, permits, code compliance, appraisal findings, marketability, and the documentation that actually exists may all affect that determination. Missing permits or unresolved zoning and code issues can prevent a lender from treating a space as an eligible ADU or from using its projected rent. Requirements also vary by program, so a unit that clears one loan type may not clear another.
Not every finished basement or converted garage is an ADU in the sense that a lender or appraiser means. Classification depends on the structure itself, the local zoning, the permitting history, and the rules of the loan program.
On the appraisal side, it helps to know what an appraiser is actually doing. The appraiser determines whether the space meets the applicable definition of an ADU and analyzes its contributory value based on the property and the available market data. An ADU may be reported separately from the primary dwelling's gross living area, even when the unit is fully legal. A permitted ADU may improve marketability or contribute value, though no particular appraisal result or increase in value can be promised. Missing permits, safety concerns, zoning questions, or a thin set of comparable properties can complicate both the appraisal and the financing.
A buyer should request the permit history. Permit records alone do not determine mortgage eligibility, so the property still needs review by the lender, the appraiser, the inspector, and the appropriate local authority as the situation calls for.
What Atlanta Buyers Should Verify Before Relying on ADU Income
If you are looking at a house-hacking strategy in Edgewood, East Point, Kirkwood, or anywhere else in the metro where basement apartments and backyard units are common, here is where I would focus early.
Ask for the permit history from the City of Atlanta, DeKalb County, or whichever jurisdiction the property sits in, and ask the seller directly what documentation they have. Get the loan program settled with your lender before you fall in love with a property, because the program drives what is possible. Confirm with your lender what appraisal documentation the file will need and whether a Form 1007 rent schedule is being ordered. If there is a tenant in place, ask whether the lease is transferring and get a copy. And have an honest conversation with your lender about your own rental management history, because with Fannie Mae that history changes whether positive rent adds to your income or only offsets the housing payment.
The order matters. These questions are cheap to ask in week one and expensive to discover in week three.
What Sellers With an Existing ADU Should Investigate
If you already have a unit on your property, the question worth answering before you list is what documentation exists and what a buyer's lender is likely to make of it.
If the unit was never permitted, you can investigate whether it may be brought into compliance. I would not assume the answer either way. It depends on current zoning, setbacks, the unit's size and location on the lot, ceiling height, egress, electrical, plumbing and mechanical work, structural conditions, fire and life-safety requirements, the inspections required, and the rules of the jurisdiction you are in. Some of those are straightforward. Some are not, and in certain cases compliance may not be achievable at all.
In addition to my real estate work, I serve as a project manager with Park Atlanta Homes on renovation and ADU-related projects. That experience has shown me why buyers and sellers need to investigate the construction and permitting history early. Whether an existing unit can be brought into compliance depends on the property and the applicable jurisdiction, and it is a question for the appropriate professionals and the local permitting authority rather than something to guess at.
One more thing on the selling side. Sellers should not misrepresent the permitting or approval status of an ADU or other improvements. Questions about your specific disclosure obligations belong with a Georgia real estate attorney.
If you are weighing a house-hacking strategy where an ADU carries part of your mortgage, I have written more on how buyers are using multi-family and ADU strategies to buy with as little as 3.5% down. And if you are still working out what you need saved before you get to this stage, my guide on down payment and closing costs in Atlanta is a good place to start.
FAQ
Can ADU rental income help me qualify for a mortgage?
It may. Fannie Mae, Freddie Mac, and FHA each allow ADU rental income to be considered under their own requirements. Whether it helps in your case depends on the property, the documentation, the loan program, and your lender's underwriting.
Does the ADU have to be permitted?
Permitting and zoning status are part of what the lender and appraiser evaluate, and requirements vary by program. Freddie Mac states that rental income from an illegal ADU may not be used to qualify. Missing permits or unresolved code and zoning issues can prevent a lender from treating the space as an eligible ADU. Your lender and the appraiser make that determination on the specific property.
What percentage of the rent may be considered?
Under Fannie Mae's current guidance the lender generally begins with 75% of the supported monthly gross rent, then subtracts the property's PITIA. FHA generally looks at 75% of the lesser of the appraiser's fair market rent or the lease amount, with a lower percentage on 203(k) loans. Starting at 75% is not the same as adding 75% of the rent to your income.
Can projected rent be used if the ADU is vacant?
It may be, through the appraiser's opinion of market rent on the applicable rent schedule. Requirements vary by program and lender, so confirm it with your loan officer rather than assuming it.
Does landlord experience matter?
With Fannie Mae, yes. A borrower with at least 12 months of rental property management experience may be able to use positive adjusted net rental income in qualifying. A borrower with less than 12 months may generally only use positive rental income to offset the property's PITIA. Freddie Mac may require landlord education in some circumstances.
Is there a limit on how much ADU income can be used?
Yes. Fannie Mae limits qualifying rental income from the ADU to 30% of total qualifying income. FHA limits ADU rental income to 30% of total monthly effective income. Freddie Mac applies its own 30% limit. The exact application is the lender's call.
Will an ADU be included in the home's gross living area?
Often not. An ADU may be reported and adjusted separately from the primary dwelling's gross living area, even when the unit is legal. That is an appraisal convention, not a judgment about the unit's quality or value.
What should I request before buying a home with an ADU?
Permit history from the local jurisdiction, any documentation the seller has on the construction, a copy of the lease if a tenant is in place, and early confirmation from your lender about what appraisal documentation your file will require.
Can an existing unpermitted unit be brought into compliance?
Sometimes, and sometimes not. It depends on zoning, setbacks, unit size and location, ceiling height, egress, electrical, plumbing and mechanical work, structural conditions, fire and life-safety requirements, required inspections, and the rules of the jurisdiction. Cost and feasibility vary widely, so this is a question for the local permitting authority and the appropriate licensed professionals.
Do Fannie Mae, Freddie Mac, and FHA use the same rules?
No. They share some concepts, including a 30% cap and a 75% starting point in various forms, but their eligibility, documentation, appraisal, and borrower requirements differ. Assume the program matters and confirm the details with a lender who works with that program.
Let's Talk
If you are considering an Atlanta property with a basement apartment, garage conversion, or detached ADU, I can help you evaluate the real estate side of the opportunity, request the available property records, and connect the financing questions to the right lender early. Schedule a consultation at kristenjohnsonrealestate.com/schedule.
Come as you are, come on home.