The Quick Read: Yes, it can count, but only when the unit is legal, nightly use is allowed for that specific unit, and the lender’s program accepts short-term rental income and can document it. Miss any one of the three and the ADU’s nightly income drops out of the file. The lender then falls back on long-term rent or gives the unit no credit at all. Here is what decides it:
- Legal status comes first. The ADU needs a permit and zoning that allows it.
- Permit is not the same as short-term rental rights. Local rules decide whether nightly stays are allowed.
- Evidence matters. Purchases lean on a projection report. Refinances lean on hosting history.
- The income gets trimmed. Lenders rarely use gross booking figures as-is.
- Coverage is not profit. DSCR compares income to the housing payment only.
An accessory dwelling unit (ADU) is a second, smaller home on the same lot: a backyard cottage, a garage conversion, or a basement apartment. A DSCR loan is reviewed for a rental on the property’s income instead of your personal income. The lender compares monthly income to the full monthly housing obligation. This guide walks through how an ADU changes that picture. For the basics, see Lendmire’s complete DSCR loans guide.
Short-Term Rental Calculator
Run the STR numbers in your market
Rate source: Freddie Mac 30-yr average via FRED® — Federal Reserve Bank of St. Louis · effective Oct 15, 2026
Prefilled with starting assumptions — enter your nightly rate, occupancy, taxes, and insurance for a more accurate picture.
Short-term rental income is documented with a 12-month history or a market data report. Program parameters update from Lendmire’s centralized guideline source.
As of Oct 15, 2026 · General Freddie Mac market benchmark, not a Lendmire loan offer. Nightly rate, occupancy, taxes, and insurance are editable estimates. 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.
How Does a DSCR Loan Count Rental Income?
A DSCR loan divides qualifying monthly income by the monthly obligation: principal, interest, taxes, insurance, and any HOA dues (together, PITIA). Only the top number moves. The lender decides how much of the rental income to count, and that choice drives everything else.
Across the wholesale network Lendmire works with, 1.00 is where select programs start. It is a floor for specific programs, not a universal standard. A separate select-lender path takes coverage below 1.00, with leverage and terms adjusted. Stronger ratios generally open better pricing and leverage.
Your income, your traditional personal-income documentation, and your debt-to-income ratio are not the focus. Credit and reserves still apply. Qualification runs primarily on property-level rental income covering the payment, subject to lender guidelines.
DSCR loans are designed for non-owner-occupied investment properties. Because they are business-purpose investor loans, they are reviewed differently from a standard owner-occupied mortgage.
Why Does the ADU’s Legal Status Come First?
An ADU that is not legal cannot support qualifying income. Everything else in the file depends on that. Lenders want a permit, a certificate of occupancy where one applies, and zoning that allows the unit.
You can see the same instinct in agency programs, which are a contrast case here, not the rule for DSCR. Rates are not quoted here. HUD Mortgagee Letter 2023-17 likewise says an ADU must comport with zoning, which may include a legal nonconforming use.
That letter also has the appraiser decide whether the property is a single-family home with an ADU or a two-family dwelling. This classification matters for DSCR too. It decides which appraisal rent form applies and how the unit is counted.
Unpermitted units are the weak spot. Investors talk about them on DSCR files, but you should not plan around one. A unit with no permit puts the income, the appraisal, and the insurance all in question at once.
Does a Permit Mean You Can Rent the ADU Nightly?
No. A building permit lets you build and occupy the unit. It does not grant the right to rent it by the night.
Short-term rental rules can vary by city, county, HOA, and property type, so investors should confirm local rules before relying on projected rental income. Many places that welcome ADUs still restrict nightly stays. Some require stays of 30 days or longer. Others cap nights per year, require registration, or collect a lodging tax.
California shows how local this gets. Builder commentary says state law lets cities require ADU rentals of more than 30 days, and one California ADU builder says most cities do. Another builder stresses that a permit never grants a short-term rental right. Those two sources describe the state rule a little differently. That is itself the lesson: treat the local ordinance as the final word, not a summary of it.
A lender that sees an ADU in a restricted area will not count nightly income, however good the projection looks. Confirm the rule before you go under contract.
How Is ADU Short-Term Rental Income Documented?
Documentation depends on whether you are buying or refinancing. Across the select lenders in Lendmire’s network, the pattern is consistent even where details differ.
| Situation | Typical evidence | Main weakness |
|---|---|---|
| Purchase, no history | Third-party projection report | Estimate, not results |
| Purchase, appraiser method | Appraisal rent schedule | Often reflects long-term rent |
| Refinance, active host | Platform payouts or manager statements | Needs about 12 months of history |
| Any case, fallback | Long-term rent schedule | Usually lower than nightly income |
Projection reports. On a purchase, many programs accept a market-data projection from a service such as AirDNA or Rabbu. The report estimates what a comparable unit earns. Lenders then trim it before using it.
Trailing history. On a refinance, lenders prefer real results: platform payouts, property-manager statements, or bank deposits. Short-term rental programs typically expect about 12 months of hosting experience.
The appraisal. The appraiser’s rent schedule is a long-term rent tool. Fannie Mae‘s appraiser update notes that the 1007 form estimates monthly market rent for a one-unit investment property and is not meant to estimate a nightly fee. Fannie Mae is not a DSCR lender. The point is only that the appraisal form measures monthly rent, not nightly income. If the appraiser reports only long-term rent, a strong short-term rental can look weak on paper.
Ask any lender or broker up front which method applies: the appraisal rent figure, a short-term analysis, or both. That one question can change the whole file.
What Haircut Do Lenders Apply to the Income?
Lenders rarely count gross bookings. They reduce the figure before running the ratio, because gross revenue ignores cleaning, platform fees, and vacancy between guests.
Apply a haircut to the booking-site income and the ratio drops, so a property that appears to be around 2.00 can land closer to 1.60 on a file. Treat that as an illustration of how a haircut works, not as a program rule. Each lender in the network sets its own adjustment.
The takeaway is simple. A property that looks like 2.00 on a booking site may be closer to 1.60 on a file, and lower still on a conservative one. Model the income more than one way before you commit.
Where Does the ADU Income Sit in the File?
How the lender treats the ADU depends on how it classifies the property. Three setups come up most often:
1. One property, one income line. The main house and the ADU are underwritten together as a single rental, often with combined income.
2. Two units. The ADU is treated like a second unit with its own rent line, as on a duplex.
3. Mixed use. The main house is rented long-term and the ADU nightly. Each income type needs its own support.
Mixed use is the setup that needs the most explaining, because the lender must evidence two kinds of income in one file. If you plan to run it that way, say so at the start.
Worked Example: A Pass and a Thin Case
These are modeled assumptions, not market data. They use ratios only.
Case one. An investor buys a house with a legal, permitted ADU at 75% LTV on a short-term rental purchase, the top of the range for the strongest files. The projection report, after the lender’s haircut, covers the full monthly obligation at roughly 1.3x. That clears the 1.00 floor with room. Subject to credit of 640 or better and the host-experience expectation, this is the kind of file lenders can work with. Leverage, reserves, and pricing vary by lender and program; the final terms follow the full file review.
Case two. Same property, but the projection is soft and the lender trims it hard. Coverage lands near 1.0x on the short-term figure, and the appraiser’s long-term rent figure puts it below 1.00. Now the structure matters. Options a lender may review include a lower loan-to-value, a different income method, or a select-lender path for coverage below 1.00 with leverage and terms adjusted. Eligibility depends on lender guidelines, credit approval, and property review.
Notice what neither case says: that the investor makes money. Clearing 1.00 is not positive cash flow. DSCR compares income to PITIA only. Repairs, vacancy, management, utilities, cleaning, and capital expenses all sit outside the calculation. Run those numbers separately before you buy.
A larger down payment can lift the ratio by shrinking the payment. It does not erase leverage caps, credit floors, reserve rules, or property eligibility. The strongest files pass both tests: enough equity and enough rental coverage.
What If the ADU Is New and Has No Booking History?
A new ADU has no track record, and the lender knows it. Plan the sequence instead of hoping:
1. Build the unit with permits and get final sign-off.
2. Confirm the local short-term rental rules allow nightly use of that unit.
3. Start hosting and keep clean records: payouts, statements, and deposits.
4. Refinance once history exists.
On a refinance, short-term rental programs in the network generally allow up to 70% LTV, and cash-out also tops out at 70% on short-term rental collateral. Those are ceilings, not promises. Lenders may also want seasoning, the waiting period between events, before a cash-out. For standard rentals, cash-out generally tops out near 75% LTV with about six months of seasoning. Short-term rental terms can differ.
In the meantime, the unit may be underwritten on long-term rent. That is a fair bridge, but it is a lower number.
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.
Can You Live in the Main House and Rent the ADU?
Usually not on a DSCR loan. These loans are built for non-owner-occupied investment properties. If you live on the property and rent the ADU, you are in a different lane, and owner-occupied programs with their own rules apply. Many of those programs treat nightly income more cautiously than a DSCR program does.
If you plan to move out and rent both units, the DSCR route becomes a real option. Plan the occupancy honestly before you apply. The file has to match the plan.
When Do You Compare DSCR With Other Loans?
Agency-style loans can count ADU rent in some owner-occupied cases, with conditions and caps. Those are agency rules, not DSCR rules. They show why a pure rental purchase usually moves to DSCR: the file qualifies primarily on the property’s income, not on yours.
For the conventional-side view of nightly income, Lendmire’s piece Does Short-Term Rental Income Count on a Conventional Loan? covers it directly.
What If the Short-Term Numbers Don’t Work?
You have fallbacks, and each one is worth pricing before you give up on the deal.
- Qualify on long-term rent. Lower income, simpler documentation.
- Run it as a mid-term rental. Furnished stays of 30 days or longer can be a legal alternative where nightly stays are banned. One caution: a guest who stays past 30 days may gain tenant rights in some cities.
- Adjust leverage. A lower LTV can lift the ratio.
- Ask about select-lender paths. Coverage below 1.00 is available through select lenders in the network, with leverage and terms adjusted.
Some property types are simply not offered. DSCR programs in the network do not cover manufactured homes, log homes, or barndominiums, so an ADU of one of those types will not work.
Key Terms Defined
ADU (accessory dwelling unit): A second, smaller home on the same lot as the main house.
DSCR (debt service coverage ratio): Qualifying rental income divided by the monthly housing obligation.
PITIA: Principal, interest, taxes, insurance, and HOA dues, if any.
LTV (loan-to-value): The loan amount as a percentage of the property’s value.
Seasoning: The waiting period a lender wants between two events, such as buying and refinancing.
Haircut: The reduction a lender applies to projected income before using it.
Pre-Application Checklist
Gather these before you talk to a lender:
- Permit and certificate of occupancy for the ADU
- Evidence that local rules allow nightly stays in the unit
- Platform payouts, manager statements, or a projection report
- Insurance that covers short-term rental use
- HOA documents, if any apply
- Your credit profile and reserve funds
Reserves vary by lender, leverage, loan size, and transaction type. Around six months of PITIA is common, though some files see them waived and larger loans can step up. Loan sizes run up to $3,000,000 on standard programs, and above $2,500,000 the network generally holds to 30-year fixed structures.
Tax treatment can depend on how the funds are used and how the property is held; investors should keep clear records and speak with a qualified tax professional before relying on any deduction.
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. Reach the team at 828-256-2183 or request a quote. Program details change and every file is underwritten individually. This is not a commitment to lend.
Frequently Asked Questions
Can Airbnb income from an ADU count toward a DSCR loan?
Yes, when the ADU is legal, nightly rental is allowed locally, and the program accepts short-term income. The lender documents it with a projection report on a purchase or hosting history on a refinance. Expect the figure to be reduced before it enters the ratio.
Does the ADU have to be permitted?
Yes. An unpermitted unit puts the income, the appraisal, and the insurance in doubt. Lenders want permit and zoning evidence in the file, and a legal unit is the starting point for every other question.
Do I need booking history?
Not always on a purchase, where a projection report can support the income. On a refinance, expect lenders to want history, and short-term rental programs typically look for about 12 months of hosting experience. A credit score of 640 or better is the usual short-term rental minimum.
What if the appraiser’s rent figure comes in low?
The appraisal rent form measures monthly long-term rent, so it often understates nightly income. Ask your broker whether the lender will weigh a projection or hosting history alongside it. If not, consider a lower LTV or a different lender in the network.
Can I count both the main house and the ADU?
Often yes, as combined income or as two units, depending on the program and how the appraiser classifies the property. A mixed setup, with a long-term main house and a nightly ADU, needs support for each income type. The final treatment is confirmed in underwriting.
About Lendmire
Lendmire is a DSCR-focused mortgage brokerage, NMLS# 2371349, placing investor loans across 41 markets, including Washington, D.C. DSCR eligibility is generally reviewed by the lender around a property’s rental income rather than personal income documentation, which fits LLC-held rentals, self-employed investors, and portfolios scaling past conventional financed-property limits. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.
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References
1. HUD Mortgagee Letter 2023-17
2. United Build Partners: ADU short-term rental rules
3. IMKAT Construction: Airbnb an ADU in California
4. Fannie Mae
This article is part of Lendmire’s short-term rental loan program — full qualification details, guidelines, and scenarios live on the program page.
Related reading: How to Show Offseason Mid-Term Income to a DSCR Lender · Short Sale vs Lost Rental for a DSCR Loan Waiting Period · How to Shop and Document Rental Insurance Before a DSCR Loan
Brandon Miller
Founder & CEO, Mortgage Loan Originator, Lendmire LLC
- Mortgage Loan Originator · NMLS# 1129696 · Verify on NMLS Consumer Access
- North Carolina Real Estate Broker · License# 343312 · Verify on NCREC
- North Carolina Insurance Producer · License# 19053198 · Property, Casualty, Life, Health · Verify on NAIC SBS
- Lendmire LLC · Firm NMLS# 2371349 · Verify firm licensure
Legal disclosures. Lendmire (NMLS# 2371349) is a state-licensed mortgage brokerage that arranges financing through wholesale lender relationships. Lendmire is not a direct lender, depository institution, or registered financial advisor. The discussion above is general informational content about real estate financing — it is not financial, legal, or tax advice, and readers should consult licensed professionals for guidance on their individual circumstances. Loan inquiries are subject to lender underwriting; this article does not represent a commitment to lend. Loan terms, rates, and qualification standards vary by borrower, property, and state, and are subject to change at any time. Equal Housing Opportunity. NMLS Consumer Access: nmlsconsumeraccess.org.