Sometimes, but less often than homeowners hope. Fannie Mae, Freddie Mac and FHA let lenders count part of the rent from an ADU, mainly on purchases and refinances that do not take cash out, with appraisal support and a cap on its share of your income. For a unit not yet built, most financing still rests on your current income.
That gap matters, because the loan that pays for construction usually has to be approved before the unit exists. This article separates what the major mortgage programs publish from what individual lenders decide, explains how rent gets documented, and shows where the rent can realistically help. For the full menu of products, see our guide to paying for an ADU in Washington.
Two Separate Questions About ADU Rent
The first question is whether the unit will pay its way. That is your own budgeting decision, and you can use whatever assumptions you trust.
The second question is whether a lender will add the rent to your qualifying income. That decision follows the lender’s rules and the program behind the loan, and it is often more conservative than your own forecast. Lenders typically count only part of the rent, require evidence of what the unit can earn, and limit how much of your total income can come from it.
Keep the two apart. A plan that works on your spreadsheet can still fall short at underwriting if it relies on rent the lender will not recognize.
What the Major Mortgage Programs Now Publish
Fannie Mae
In an October 2025 Selling Guide update, Fannie Mae amended its rental income policy so that income from an ADU can be considered toward qualifying income when specific requirements are met. Before that change, ADU rent was generally limited to its HomeReady program. The current policy applies to a one-unit principal residence with an ADU, on purchase or limited cash-out refinance transactions, and counts rent from only one ADU. The amount used is capped as a share of the borrower’s total qualifying income, and the rent must be supported by the appraiser’s comparable rent analysis and, where one exists, a lease.
Fannie Mae’s property rules long limited a one-unit home to a single ADU. A December 2025 update opened the door to more than one for lenders working under its newest appraisal data standard, so if your lot will hold two units, ask which policy your lender follows.
Freddie Mac
Freddie Mac also allows ADU rental income on a one-unit primary residence when certain requirements are met, on purchase and no cash-out refinance transactions. Its published requirements include a full appraisal, comparable sales that include a property with an ADU, comparable rentals that include a rented ADU, and confirmation that the ADU is allowed under zoning. Rent documented by a lease is counted at a discount, total ADU income is capped as a share of qualifying income, and purchasers without landlord or property management experience may need to complete landlord education.
FHA
FHA’s Mortgagee Letter on ADUs, issued in October 2023, lets borrowers use some of the actual or projected rent from an ADU on a one-unit property to help meet income requirements. Without a rental history, the lender takes the appraiser’s market rent and any lease, picks the lower figure and counts only a reduced portion of it. ADU income is capped as a share of total qualifying income, and FHA does not allow it on a cash-out refinance application.
An Existing Unit Versus One That Is Still on Paper
These published allowances are written around a property that has an ADU when the loan closes. They work well for a buyer purchasing a home with a finished, legal unit, or for an owner whose ADU is already built.
A unit you are about to build is a different case. The main published route that counts rent on a unit being added is FHA’s renovation program, which applies its own, more conservative calculation and only covers the kinds of ADU work that program allows. Outside that, financing for new construction, such as a HELOC, a home equity loan or many construction loans, is generally approved on your income today. Some lenders keep loans on their own books and set their own policies, so it is worth asking directly, but plan as if the rent will not count until the unit exists and is documented.
Why Cash-Out Refinances Rarely Count the Rent
Each of the three programs limits ADU rent to transactions that do not take cash out: purchases and limited or no cash-out refinances. FHA states the exclusion directly. That matters for ADU owners, because a cash-out refinance is one of the common ways to raise construction money from an existing home.
In practice, if you plan to pull equity out to build, expect to qualify on your existing income. The broader trade-offs of that route, including what it does to a low existing mortgage rate, are covered in our refinancing decision guide.
How the Appraisal Supports a Rent Figure
Lenders lean on the appraiser rather than on your estimate. For a one-unit home with an ADU, the appraiser typically completes a comparable rent schedule: a short analysis of similar rentals nearby, adjusted for size, condition and features, ending in an opinion of market rent for the unit.
The quality of that analysis depends on local data. Freddie Mac, for example, expects at least one of the comparable rentals to be a rented ADU and at least one comparable sale to include an ADU. In neighborhoods where ADUs are common, that is straightforward; where they are rare, the appraiser has fewer good matches. The same evidence that helps an appraiser also helps you price the unit, and our guide on setting a realistic ADU rent shows how to build a comparable set.
Paperwork That Helps the Rent Count
A signed lease, if the unit is already rented, along with proof the rent is being paid.
Recent tax returns showing rental income, if you have a history of renting the unit; FHA, for example, looks to the borrower’s returns when that history exists.
Evidence that the unit is legal: the building permit and final inspection, since programs require the ADU to be allowed under local zoning.
A record of landlord or property management experience, which can affect how rent is calculated and whether landlord education is required.
The appraisal with its rent analysis, which the lender orders.
Our article on earning rental income from a Seattle ADU covers the practical side of getting a unit leased and keeping records from the first month.
Building First, Then Letting the Rent Work
For many owners, the realistic sequence is to finance construction on current income, finish and rent the unit, then use the documented rent later. Once the ADU exists, has a lease and appears on your tax returns, a future purchase-money or non-cash-out refinance on the property is where the published rules are most likely to recognize it.
That makes the choice of construction financing important. A construction-to-permanent loan, for instance, sets the long-term mortgage at the start, while a standalone construction loan is replaced at completion, which is the moment the finished unit could be considered. How those two paths end is explained in our article on construction lending for backyard units. Freddie Mac also publishes an option for a no cash-out refinance to repay short-term financing used for ADU work completed before the new loan, under its renovation product; confirm with a lender whether it fits your timeline.
Conservative Assumptions for Your Own Plan
Lenders discount rent for vacancy and expenses, and your own budget should too. Assume a gap between completion and the first tenant, an occasional empty month at turnover, and maintenance that grows as the unit ages.
Size the loan so the payment fits your income without the unit, then treat rent as the margin that speeds up payoff. Our step-by-step method to estimate the monthly cost of an ADU shows how to build that number. To see which partner offers can cover finishes or a gap, check the current ADU financing options and raise the rental plan in your first consultation.
FAQ
Can rent from an unpermitted ADU be counted?
Generally not. The published requirements expect the ADU to be legal under local zoning, and appraisers check whether the unit fits the program’s definition, so legalizing the unit comes before counting its income.
Does the lender use my asking rent or the appraiser’s figure?
Lenders anchor to the appraiser’s market rent, and where a lease exists they typically compare the two and use the lower amount before applying their own discount.
Can I count ADU rent if I have never been a landlord?
Possibly. Programs allow it in some cases, but the calculation or the requirements can be stricter without a rental history, and Freddie Mac may require landlord education for first-time landlords on purchases.
What if my lot will have two ADUs?
Most published ADU guidance was written with one accessory unit in mind. If your plan includes two, confirm early that the lender can finance that configuration before you design the second unit.
Is short-term rental income from an ADU treated the same way?
Not usually. The ADU policies rely on market rent from an appraisal and on leases, which fit long-term rentals, so income from nightly stays generally faces different documentation and a separate lender review.