Pasadena ADU Rental Income Mortgage Rules

Short answer: Yes. On a Fannie Mae conventional loan, rent from one ADU on a one-unit home you will live in can now count toward your qualifying income. It applies to purchases and limited cash-out refinances, it is capped at 30 percent of your total qualifying income, and it needs an appraiser's rent schedule (Form 1007) to back up the rent. Fannie Mae turned this on in Desktop Underwriter version 12.1 on March 21, 2026.

Why this matters in Pasadena

Pasadena has a large stock of older single-family homes with detached garages, rear guest houses, and lots that fit an ADU. Many listings advertise a "guest house with income potential," but until 2026 most conventional loans gave buyers no qualifying credit for that rent. Now a legal, separate unit can help you qualify for a higher price or a lower debt-to-income ratio, which matters in a market where many homes sit near or above the 2026 LA County high-balance loan limit of $1,249,125 for one unit.

The Fannie Mae ADU income rules, in plain words

Rule	What it means for you
One-unit principal residence	You must live in the main home. The property is a single-family home with one ADU, not a 2 to 4 unit building.
Purchase or limited cash-out refinance	A cash-out refinance cannot use the ADU rent.
One ADU only	Rent can come from one ADU, even if the lot has more than one unit.
30 percent cap	ADU rent used to qualify cannot be more than 30 percent of your total qualifying income.
Rent documentation	The appraiser completes a Form 1007 rent schedule specific to the ADU. If a tenant is already in place, the lender reviews the lease.
Landlord experience	With less than 12 months of property management experience, the rent can generally offset only your housing payment.
What counts as an ADU	A separate entrance, kitchen (cabinets, counter, sink, and a stove or stove hookup), sleeping area, and bathroom, smaller than the main home and on the same parcel.

Example: how the math can work

Example data only, not a quote, rate, or approval.

Say a buyer earns $12,000 a month in W-2 income and the appraiser supports $2,400 a month in market rent for the rear unit. A lender commonly counts 75 percent of gross rent, or $1,800. Total qualifying income becomes $13,800, and $1,800 is about 13 percent of that, well under the 30 percent cap. If the buyer has less than 12 months of landlord experience, the usable rent is limited to offsetting the housing payment, so the benefit can be smaller. Your actual numbers depend on the appraisal, your credit, and the loan program.

Pasadena permit checks before you write an offer

Confirm the unit is permitted. Ask the listing agent for permits and finals, and verify with the City of Pasadena Permit Center. Unpermitted conversions can hurt the appraisal and rental credit.
Know the current rules. Pasadena's updated ADU and Junior ADU regulations took effect May 20, 2024 under Ordinance No. 7420. New units generally need 4 foot side and rear setbacks.
Parking. Pasadena requires one space per ADU or per bedroom, whichever is less, but waives it near transit (within a half mile walk), in historic districts, and for units inside existing space.
Planning to build instead of buy? As of August 2026, the city offers one free 2025 building code compliant standard plan (a 374 square foot studio). Older standard plans expired December 31, 2025 except for properties red tagged by the Eaton Fire.

Is a Fannie Mae loan the right fit?

This rule is a strong fit for owner-occupant buyers with W-2 or documented self-employment income who want rental help on a single-family home. If you are buying a true 2 to 4 unit property, different rental rules apply. If you are buying as an investor, a DSCR loan qualifies on the property's rent instead of your income. For a full look at what you can afford across the region, see our California buying power and refinance guide, and if you are also shopping the coast, our South Bay and Torrance mortgage guide. Investors weighing tax strategy should review questions to ask your CPA before buying investment property.

Frequently asked questions

Can rent from a guest house or ADU count toward my mortgage income in Pasadena?

Yes, on a Fannie Mae conventional loan. Since Desktop Underwriter version 12.1 (March 21, 2026), rent from one ADU can count toward qualifying income when you buy, or do a limited cash-out refinance on, a one-unit home you will live in.

How much of my income can come from the ADU?

ADU rent used to qualify is capped at 30 percent of your total qualifying income. The lender typically counts 75 percent of the market or lease rent, supported by a Form 1007 rent schedule from the appraiser.

What if I have never been a landlord?

Fannie Mae limits borrowers with less than 12 months of rental property management experience. In that case the ADU rent can generally only offset your housing payment rather than add extra income, so plan your budget around that.

Does the ADU have to be permitted by the City of Pasadena?

The appraiser and underwriter review whether the unit meets Fannie Mae's ADU definition and local zoning. A permitted unit is the cleanest path. An unpermitted garage conversion can reduce value or rental credit, so check permits with the Pasadena Permit Center before you write an offer.

Can I use rent from two ADUs or a JADU and an ADU?

Rental income can come from only one ADU, even when a property has more than one. Properties with multiple units need a closer program review, so share the listing details before you rely on the rent.

Does this work with FHA or VA loans?

FHA and VA follow their own rental income rules, which differ from Fannie Mae's ADU policy. Ask for a side by side comparison before choosing a loan program.

Talk through your Pasadena property

Send us the listing and your income picture, and we will show you whether the ADU rent helps, how much, and which loan program fits.

Call 424-RATE-ZEN (424) 728-3936 Book a Strategy Call

Sources

Program rules checked October 27, 2026. Guidelines change; this page is education, not a commitment to lend. All loans subject to credit approval, appraisal, and program guidelines.