How lenders treat ADU rent at a glance
You own a house with a backyard unit, or you are about to buy one, and you want both rents to help you qualify. An ADU (accessory dwelling unit) is a second, smaller home on the same lot, often called a granny flat or backyard cottage. Our main page on DSCR loans in Los Angeles covers the loan itself; this guide covers the second unit.
| Question | What lenders typically do |
|---|---|
| Does ADU rent count? | Yes at many lenders. Some count only the main house. |
| How many ADUs | Usually one per property |
| Permit status | A permitted, legal unit. Rent from an unpermitted unit is usually left out. |
| Proof of rent | A signed lease, or the appraiser's market rent on Fannie Mae Form 1007 |
| Appraisal support | Nearby rentals or sales that also have an ADU |
| Lease above market | Many use the lower of lease and market rent. Some allow a higher lease within a cap. |
| Minimum DSCR | 1.0 at most lenders. Some go lower with more money down. |
| Down payment on a purchase | 20% to 30% |
| Occupancy | Investment only. You cannot live in either unit. |
| Paying to build the ADU | Not usually. The loan is for a finished, rentable property. |
Typical market practice as of November 2026, drawn from published lender guidelines and industry guides. Advanced Funding Solutions is a broker and does not set these rules. The lender that funds your loan sets your actual terms.
How ADU rent changes your DSCR
Most investors look at an ADU because the main house alone does not cover the payment at Los Angeles prices. DSCR means debt service coverage ratio: the lender divides the monthly rent by the monthly payment. That payment includes principal, interest, property taxes, insurance and any HOA dues.
Say the main house rents for $4,000 and the payment is $5,600. The ratio is about 0.71, below where most lenders stop. Add a permitted ADU renting for $2,200 and the ratio climbs to about 1.11, because the payment does not change.
That is the whole appeal in one example. You can run your own numbers in our DSCR calculator with and without the ADU rent.
Whether the lease or the appraiser sets the rent
You need to prove what each unit earns, and the lender wants a number it can defend. With a tenant in the ADU, that usually means the signed lease. On a purchase or an empty unit, the appraiser writes a market rent on Fannie Mae Form 1007, the rent schedule. It should show a figure for the ADU as well as the main house.
The appraiser backs that figure with comparables, which are nearby properties that rented or sold recently. For the ADU to count, many lenders want at least one comparable that also has an ADU. When the appraiser cannot find one, the lender may cut the ADU rent or leave it out.
When your lease and the appraiser disagree, many lenders count the lower number. Some will use a higher lease within a cap. Ask about this before you sign a lease well above or below market.
Why the permit matters more than the rent
Investors are often surprised that a nicely finished backyard unit adds nothing to the ratio. The reason is the permit. Lenders count rent from a legal, permitted ADU, and most leave out rent from a unit the city never signed off on.
An unpermitted unit can also lower what the appraiser says the property is worth. Before you write an offer, check the city's building records for a permit and a final sign off on the ADU. If the records stop short, plan your numbers on the main house rent alone.
One home with an ADU or two separate units
You might hear the same property described as a house with an ADU or as a duplex. To a lender, the difference changes the paperwork. A single family home with one ADU usually appraises as a one unit property, with the ADU rent shown on Form 1007.
A building that is legally two units appraises on Form 1025, the 2 to 4 unit rent schedule, and every unit's rent counts as a matter of course. Fewer lenders take a 2 to 4 unit building with an ADU added on top. If you are not sure how your property is classified, the permit record will tell you.
Can a DSCR loan pay to build an ADU
Usually not, which disappoints investors who hoped to fund the build with the rent it will earn. A DSCR loan lends against rent a property can earn today. A unit still under construction earns nothing yet.
The common path is to pay for the build with cash or construction financing, then refinance into a DSCR loan once the unit is finished and rented. Some investors pull cash from a rental they already own with a DSCR cash out refinance, where the maximum LTV usually runs 70% to 75%. LTV means loan to value, the loan as a share of the property's value.
Our guide to DSCR loans for new construction walks through that build, then refinance, path in more detail.
Los Angeles rent rules that reach your ADU
Your ratio rests on the rent you can charge, so the city's rent rules matter as much as the lender's. The Rent Stabilization Ordinance, or RSO, generally covers rental units in the City of Los Angeles built on or before October 1, 1978. It limits how much and how often you can raise rent on a covered unit.
A brand new ADU built detached from the main house is generally not covered by the RSO. According to the Los Angeles Housing Department, three situations change that:
- Converting part of an older house: if the ADU is carved out of the living space of a single family home built before October 1, 1978, both units may be subject to the RSO. An ADU made from a garage or other non-living space falls under the Just Cause Ordinance instead.
- Adding a unit next to an older house: a pre 1978 house alone on its lot is generally exempt, but once a second unit goes up on the parcel, the main house may become subject to the RSO.
- Building after RSO units left the market: an ADU built on a lot where RSO units were withdrawn from rental use under the Ellis Act can fall under the RSO too.
The second point catches investors most often. Adding an ADU can raise today's ratio while capping how fast the main house rent can grow. Units outside the RSO generally fall under the city's Just Cause Ordinance, which governs when you can end a tenancy.
The rules can also cut the rent a lender counts today. If you buy a covered property where a tenant pays well below market, a lender using the lower of lease and market rent will count the lease. Ask the Housing Department to confirm a property's status before you build your plan around a rent increase.
When a DSCR loan is the wrong fit for an ADU
If you plan to live in the main house or the ADU, a DSCR loan is not an option. A conventional loan is the usual route for a home you live in. Fannie Mae updated its guidelines in late 2025 so ADU rent can help you qualify in some cases.
If your tax returns show steady income and you are buying a pure rental, a conventional investment loan is usually the cheaper choice. Take it if you qualify. And if the ADU is unpermitted, the better first step may be legalizing it, then financing once the rent can count.
For everything a lender checks beyond the ADU, from credit to reserves, see our guide to DSCR loan requirements in California.
Talk through your numbers with us
You do not need to learn which lenders count ADU rent and which do not. Advanced Funding Solutions is a California mortgage brokerage that works with 100+ wholesale lenders. We look for the ones that fit your property, your ADU and your credit, and the lender you choose approves and funds the loan.
The first call covers the property, the permit history of the ADU and the rent on each unit. Call (818) 478-2555, or request a quote online.
For the statewide picture, see our main page on DSCR loans in California.
Frequently Asked Questions
Can I get a DSCR loan on a house with an unpermitted ADU?
Often yes, but the unpermitted unit rarely helps you qualify. Many lenders will lend on the main house and leave the ADU rent out of the ratio. The appraiser may also give the unit little or no value. If you need that rent to reach 1.0, getting the unit permitted first is the usual way to make it count.
Can I live in the ADU and rent out the main house with a DSCR loan?
No. A DSCR loan is a business purpose loan, and living in either unit makes the property your home. If you plan to live on the property, look at a conventional loan instead. Fannie Mae changed its guidelines in late 2025 so ADU rent can help you qualify in some cases on a home you live in.
Does an ADU make it easier to qualify for a DSCR loan?
Often, yes. A second rent check raises the top of the ratio while the payment stays the same, so a house that falls short alone can clear 1.0 with a rented ADU. That only works when the unit is permitted and the appraiser can support its rent with nearby rentals that also have an ADU.
How soon after finishing an ADU can I refinance with a DSCR loan?
Usually as soon as the unit is finished, signed off by the city and ready to rent. A signed lease makes the rent easier to prove than an estimate. For a cash out refinance, lenders ask you to have owned the property for anywhere from no time at all to about six months.
Will building an ADU raise my property tax payment?
In most cases, yes, but only for the new unit. The county assessor adds the value of the new construction to your assessed value, and the rest of the property keeps its existing tax base. That higher tax bill becomes part of the monthly payment the lender divides into your rent.
Advanced Funding Solutions Inc. is a licensed mortgage brokerage, not a lender. NMLS #1277693. CA DRE #01973518. Consumer mortgage loans are licensed in California and Florida; DSCR loans are business purpose loans. All loans are subject to credit, income, asset, property, and underwriting approval. The funding lender sets rates, terms and conditions, which can change without notice. Market practices on this page are typical industry figures as of November 2026, not an offer or a commitment to lend. Rent rule summaries are general information, not legal advice. Equal Housing Opportunity.