The Quick Read: A DSCR lender usually counts the lower of your actual ADU lease or the appraiser’s market-rent opinion. That rent is added to the main house’s rent, and the total is divided by the full monthly housing payment. The unit has to be permitted and appraised as rentable first, subject to lender guidelines.
- Lower of two numbers. Your lease and the appraiser’s market rent compete, and the smaller one generally wins.
- Permit first. Without proof the unit is legal, most programs leave its rent out entirely.
- Collected rent is not rent used for lender review. What lands in your bank account only matters if the appraisal and paperwork support it.
- The ADU can swing the file. It can be the difference between clearing a program’s minimum coverage and missing it.
An ADU (accessory dwelling unit) is a second, smaller home on the same lot. It might be a garage conversion, a backyard cottage, or a basement apartment. Investors love them because one purchase produces two rent streams. Lenders are more careful, because one of those streams has to survive an appraisal and a paper trail.
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Rate source: Freddie Mac 30-yr average via FRED® — Federal Reserve Bank of St. Louis · effective Oct 29, 2026
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Program parameters update from Lendmire’s centralized guideline source. Taxes and insurance are editable estimates.
As of Oct 29, 2026 · General Freddie Mac market benchmark, not a Lendmire loan offer. Rent, nightly rate, occupancy, taxes, and insurance are editable estimates. Short-term rental figures are estimates only and vary significantly by season, property type, management approach, and local short-term-rental rules — confirm local regulations before relying on them. Qualifying income for short-term rentals varies by program — some use appraisal market rent, others use documented STR history or projections — and is confirmed in underwriting. Not a Loan Estimate, approval, or commitment to lend. Program availability and eligibility are subject to lender guidelines, credit approval, property review, and underwriting.
Key Terms Defined
DSCR (debt service coverage ratio): The property’s monthly rent divided by its monthly housing payment. A result above 1.00 means the rent covers the payment on paper.
PITIA: Principal, interest, taxes, insurance, and any association dues. It is the full monthly payment the rent has to cover.
Rent used for lender review: The rent figure the lender actually credits. It can be lower than what a tenant pays you.
Market rent: The appraiser’s opinion of what the unit would lease for, based on comparable rentals.
Permitted ADU: A unit built or converted with local approval, so it exists legally as a separate dwelling.
Which Rent Figure Does the Lender Count?
Most programs we place files with count the lower of your signed lease or the appraiser’s market-rent opinion. The logic is simple. A lender underwrites as if it might one day have to take the property back and operate it. It will not give credit for rent a replacement tenant might not pay.
That rule produces three outcomes you can predict:
- Lease below market. The lease is used. A friendly rate for a relative or long-time tenant costs you coverage.
- Lease above market. The appraiser’s number is used. Extra rent you collect does not help the ratio.
- No lease at all. The ADU rides entirely on the appraiser’s market-rent opinion.
The main house follows the same logic. DSCR lending qualifies primarily on property-level rental income covering the payment, subject to lender guidelines. So both units are tested against the market, not against your good fortune with a tenant.
What Does “Permitted” Mean to an Underwriter?
It means paper, not a photo of a nice kitchenette. The underwriter wants evidence that the unit is a legal dwelling. An appraiser also checks this before assigning any value or rent to the space. One practicing appraiser advises borrowers to hand the appraiser and lender documentation that the ADU was legally permitted. The same advice covers listing rental income and construction costs.
A strong ADU file typically includes:
1. The final permit sign-off from the local building department.
2. A certificate of occupancy, or the local equivalent.
3. Confirmation that zoning allows a second unit on that lot.
4. Physical features that make it a true dwelling: a separate entrance, a kitchen, and its own utilities or a clear utility arrangement.
5. A signed lease and proof of the deposit and first month’s rent, if the unit is tenanted.
If your paper trail has gaps, find out early. Buyers should ask for permit records before making an offer. Builders should keep every approval document in one folder. A missing sign-off found during the appraisal is a much worse time to learn about it.
How Does ADU Rent Roll Into the Ratio?
The lender adds the main unit’s rent used for lender review to the ADU’s rent used for program review. That gross rent is divided by PITIA. The result is your coverage number.
The appraisal literature describes the same logic. An Appraisal Journal paper by Brown and Watkins treats a property with a legal ADU as a two-unit income property sitting in single-unit zoning. The appraiser surveys market rent for the ADU and combines it with the primary dwelling’s rent. That paper is dated, so use it for the concept, not for current program rules.
Run the numbers on a hypothetical file. These are modeled assumptions, not market data:
- Main house alone: rent covers the payment at about 0.80x.
- ADU lease supports about 0.40x of the payment, but the appraiser’s market-rent opinion supports about 0.35x.
- The lender uses the lower figure: 0.80x + 0.35x = about 1.15x.
Now strip the ADU out. The same file sits at 0.80x. On many programs, that is below the minimum. Coverage of 1.00 is where many select programs start. A separate select-lender path takes coverage below 1.00, with leverage and terms adjusted. Stronger ratios generally open better pricing and leverage.
This is why the ADU decision matters. It is not a small add-on. It can move a file from a stretch to a clean fit, or the reverse.
How Does the Appraisal Set the Number?
The appraisal does two jobs. It sets value, which drives loan-to-value (LTV, the loan as a share of the property’s value). It also sets market rent, which drives coverage.
Two appraisal forms matter here, and Fannie Mae’s appraiser page lists both. Form 1007 is the Single-Family Comparable Rent Schedule. Form 1025 is the Small Residential Income Property Appraisal Report, used for two-to-four-unit properties. These are appraisal forms borrowed from the conventional world. They are not DSCR rules, and each lender and program decides how it uses them.
What changes from file to file is classification. An ADU can be treated as part of a one-unit property or as a second unit. That choice affects which form is used and how the rent is captured. Some programs want a rent schedule specific to the ADU. Some report the ADU separately from the main house’s living area. Ask your broker how the program you are targeting handles it before the appraisal is ordered.
Comparables decide a lot. The appraiser needs rent comps for similar units, and often sales comps for similar ADUs. Where such comps are scarce, the income may be excluded. That is a common reason a perfectly legal ADU still contributes little to the ratio.
What Rent Counts at Each Stage of the ADU?
Here is the decision table. It maps the stage of the unit to the figure that generally counts.
| ADU stage | Rent generally counted |
|---|---|
| Planned, not built | None |
| Under construction | None |
| Finished, vacant | Appraiser’s market rent |
| Leased below market | The lease amount |
| Leased above market | The market-rent opinion |
| Newly leased | Lower of lease and market rent, with proof of receipt |
A new lease often needs support. Expect to show the signed lease, the security deposit, and the first month’s rent. Programs vary on how much lease seasoning they want, so confirm the specifics for your target program.
What Income Usually Doesn’t Count?
Collected income and qualifying income are different things. Several items investors count in their own heads rarely make it into the lender’s number.
| Income item | Typical treatment |
|---|---|
| Projected rent, unbuilt ADU | Excluded |
| Rent above market | Capped at market |
| Rent from an unpermitted unit | Generally excluded |
| Owner or family use | No reviewable rent |
| Pet fees, parking, storage | Usually not counted |
Family use deserves a note. If you or a relative live in the ADU, there is no rent to review. A below-market family lease gets scrutinized, and the lower figure is what counts anyway.
DSCR vs. conventional financing
There are two common ways to finance an investment property, and they qualify you differently — here’s how investors weigh them.
Why investors choose it
- Qualifies on the property’s rental income — no personal tax returns, W-2s, or pay stubs needed to document income.
- No personal debt-to-income ceiling to clear, so existing mortgages and obligations don’t cap your borrowing the same way.
- Can be closed in an LLC, keeping the property inside a business entity.
- Built for scaling — not held to the limit on number of financed properties that conventional financing applies.
- Underwriting centers on the deal: generally qualifies when the rent covers the payment, a 1.00x coverage ratio being a common baseline (confirmed in underwriting).
- Designed specifically for investment property, including long-term and, where the program allows, short-term rentals.
Where it’s strong
- Often the lowest ongoing financing cost for a buyer who fully qualifies on personal income — a fit for a first property or a cost-first purchase.
Trade-offs for investors
- Requires full personal income documentation and must fit within a debt-to-income limit — salary, existing debts, and other mortgages all count.
- Typically held in your personal name rather than a business entity.
- Caps how many financed properties you can carry, which can become a ceiling as a portfolio grows.
- Evaluates you as a borrower as much as the property, which usually means more paperwork.
How investors usually choose: a first or single property often optimizes for the lowest financing cost; portfolio builders often optimize for leverage, vesting in an LLC, and scaling past conventional caps. The right answer depends on your goals, the property, and current guidelines — both paths run through select lenders in Lendmire’s wholesale network, with eligibility and terms confirmed in underwriting.
Where the General Rule Breaks
Every program has edges. These are the ones that trip up ADU files most often.
Unpermitted ADU. The appraiser will likely flag it and leave it out of both value and rent. The main house may then have to qualify alone. A few specialty lenders may consider such a unit with heavy documentation, but do not plan around it. Rent collected from an unpermitted unit does not prove the unit is legal.
Short-term rental ADU. A nightly rate multiplied by 30 is not a lease. Fannie Mae’s guidance on Form 1007 says the form documents monthly market rent from comparables leased monthly. It also says the form cannot estimate a nightly short-term-rental fee. Short-term income needs its own path, typically with hosting history and its own leverage caps.
ADU being built. Projected rent from an unbuilt unit adds nothing to the test. The common sequence is to finish the unit, lease it, and then refinance. On a cash-out refinance, most programs in our network top out around 75% LTV, and about 6 months of seasoning is the common expectation.
Multiple accessory units. Some programs limit how many accessory units count. Do not assume a rule from one program applies to another. Programs vary, and this one is worth asking about directly.
Reclassification. An improperly permitted ADU can push a property into a different class, which may change leverage. The effect depends on the program and the property.
No comps, no rent. If the appraiser assigns no rent to the ADU, you have options. Compare programs that treat ADUs differently. Ask whether the appraisal instructions can be adjusted. Or price the deal without the ADU and see whether it still works.
What Does the Investor Decision Look Like?
Price the deal both ways. Run the ratio with the ADU counted, then run it with the ADU excluded. The gap between those two numbers is the risk you are carrying.
If the file clears minimum coverage either way, the ADU is a bonus. If it only clears with the ADU, then permit paperwork, appraisal comps, and lease terms become the main thing to protect.
A few program realities apply on top of the rent question. On a purchase of an investment property, most files land at 75% to 80% LTV, meaning 20% to 25% down. Credit expectations vary: a 620 floor exists in parts of the network, most programs want around 660, and 700 or above unlocks the strongest leverage tiers. Reserves commonly run around 6 months of PITIA, stepping up to about 9 months on loans above $1,500,000. These are typical ranges, subject to lender guidelines.
A bigger down payment can lower the payment and lift the ratio. It does not erase leverage caps, credit floors, reserve rules, or property eligibility. The strongest files clear both tests: enough equity and enough rental coverage.
Clearing 1.00 is also not the same as positive cash flow. DSCR compares rent to PITIA only. Repairs, vacancy, management, utilities, and capital expenses sit outside the calculation. Tax treatment varies; consult a qualified professional.
If your ADU question is really about how a different loan type counts the same unit, Lendmire has covered how much ADU rent a jumbo lender counts toward your loan and how a bank statement lender counts ADU rent. For the bigger picture of how these loans work, see the complete DSCR loans guide.
Frequently Asked Questions
Does ADU rent automatically count?
No. The unit has to be permitted, appraised as rentable, and supported by comparables. Even then, the lender counts the lower of the lease and the appraiser’s market rent. Treatment is set by each program and is subject to lender guidelines.
Does the lender use my lease or the market rent?
Usually whichever is lower. A lease below market lowers your rent used for eligibility review. A lease above market is capped at the appraiser’s figure. A vacant ADU relies entirely on the market-rent opinion.
What if my ADU is vacant?
A finished, permitted, vacant ADU can still contribute through the appraiser’s market-rent opinion on programs that allow it. Expect the appraiser to need rent comps. An unfinished ADU contributes nothing, because projected rent is not counted.
Does a higher lease help my ratio?
No. Rent above the appraiser’s market figure is generally ignored. The lender wants income a replacement tenant would reasonably pay, not the highest number you have collected.
What if the appraiser ignores the ADU?
Then the main house may have to qualify alone. Ask your broker whether another program classifies or documents ADUs differently, or whether the file works without the unit. Sub-1.00 coverage is available through select lenders in the network, with leverage and terms adjusted.
Your Next Step
If you are buying or refinancing a rental property and want to see how the numbers work, Lendmire can help you compare DSCR loan options based on the property income, credit profile, leverage, and investor goals. As a mortgage broker, Lendmire arranges DSCR investor financing through select lenders in its wholesale network, across 41 markets including Washington, D.C. Final treatment of ADU rent is set by the lender and program, and nothing here is a commitment to lend.
About Lendmire
Lendmire, NMLS# 2371349, is a mortgage brokerage focused on investor financing, arranging DSCR loans in 40 states plus Washington, D.C. — 41 markets total. Qualification is based on the property’s income rather than personal income documentation, subject to lender guidelines, making it a fit for LLC-held rentals and scaling portfolios. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.
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Informational only. Not a Loan Estimate, approval, or commitment to lend. Program availability and eligibility are subject to lender guidelines, credit approval, property review, and underwriting.
References
1. Sacramento Appraisal Blog – ADU worth
2. Brown & Watkins, Appraisal Journal (hosted by accessorydwellings.org)
3. Fannie Mae – Appraisers & Property Underwriting
4. Fannie Mae – Appraiser Update on Form 1007 and monthly market rent
This article is part of Lendmire’s DSCR loan program — full qualification details, guidelines, and scenarios live on the program page.
Related reading: How a DSCR Lender Reads Rent for a Los Angeles Triplex · Can a DSCR Lender Change Your Ratio After Prequalification? · How Much a DSCR Cash-Out Lends on an Out-of-State Rental
Brandon Miller
Founder & CEO, Mortgage Loan Originator, Lendmire LLC
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Required disclosures. Lendmire (NMLS# 2371349) operates as a licensed mortgage broker, not a direct lender or depository. The discussion in this article is general in nature and should not be relied upon as financial, legal, or tax advice — every investment scenario is unique and should be reviewed by a qualified professional. Any loan inquiry is subject to lender underwriting, and this article is not a commitment to lend or a guarantee of approval. Mortgage rates, loan terms, and program guidelines vary by borrower, property, and state, and may change without notice. Equal Housing Opportunity. Verify licensure at NMLS Consumer Access.