What the Pomona market has paid for a granny flat is read from closed sales of whole properties, because a California ADU generally cannot be sold apart from the house it sits behind. An appraisal compares Pomona houses that sold with a permitted second unit against similar houses that sold without one, in the same kind of neighborhood, and states in the report what that difference shows. There is no Pomona price per granny flat to look up, and this article quotes none; the evidence is assembled fresh for each property and shown in the report.
This article is part of the ADUs, additions and new construction series. The method behind it is in the pillar, how an ADU is appraised: permits, contributory value and the local evidence. This page stays with Pomona's sales.
What a granny flat is, in the terms the report uses
"Granny flat" is the everyday name; the report uses the legal one. Under Government Code section 66313(a), an accessory dwelling unit is "an attached or a detached residential dwelling unit" that "provides complete independent living facilities for one or more persons" on a lot with "a proposed or existing primary residence." A junior accessory dwelling unit is smaller, "no more than 500 square feet of interior livable space," and "contained entirely within a single-family residence." Those are now the governing section numbers: the State Board of Equalization's Letter To Assessors No. 2024/014 explains that Senate Bill 477 moved the ADU rules out of former section 65852.2 without changing them.
The rule that matters most for Pomona sales is in section 66314(d)(1): the unit "may be rented separate from the primary residence, but shall not be sold or otherwise conveyed separate from the primary residence," apart from the separate-conveyance rules in Article 4. Buyers do not pay for a granny flat. They pay for a Pomona lot that has one.
Where Pomona's second units sit
Pomona is one of the most varied housing markets in the coverage area, and its second units sit in different settings that do not compare with each other.
- The postwar tracts. Most of the city is postwar single-family tract housing, and garage conversions and back units are the recurring adjustments and lender questions there. A tract house with a permitted rear unit is compared first with sales in similar tracts.
- Lincoln Park, Wilton Heights and Hacienda Park. These residential historic districts hold homes from the 1880s to the 1940s, where exterior changes go through preservation review. A rear unit behind a Lincoln Park house is weighed against other older houses on older lots, not against the tracts.
- Downtown, Holt Avenue and the Fairplex. Older duplexes, fourplexes and houses divided into units are common here, and the legal unit count often differs from the records. A second dwelling on these blocks may be a legal ADU, a legal duplex, or neither.
- Phillips Ranch. The hillside planned community in the southwest has its own slope, view and HOA character, and its comparables come from inside that setting.
The Pomona area page describes these pockets and the comparable choices a reviewer would reject in each.
ADU or second unit? The line the report draws first
A lot with a house and a granny flat is not the same property as a duplex, and the report has to say which one it is before any sale is compared. For loans sold to Fannie Mae, Selling Guide section B2-3-04 says "Only one ADU is permitted on the parcel of the primary one-unit dwelling," that ADUs are "not permitted with a two- to four-unit dwelling," and that the classification "will be based on the characteristics of the property," including "the existence of separate utility meter(s), a unique postal address, and whether the unit can be legally rented."
In the older blocks around downtown, that question decides which sales are even relevant. A permitted ADU is compared with one-unit properties that have a second unit; a legal two-unit building is compared with two-unit sales. Multi-family appraisal in Pomona when the legal unit count differs from assessor records covers the second case.
How the Pomona evidence is read
Contributory value is what an improvement adds to the whole property in the market. It is measured from sales, not from build cost or a fixed share, in four moves.
- Confirm the unit. The permit, the final sign-off and the approved plans establish what was built and that it was finalled. Space that lacks them is described as found, its status is stated, and the report explains how it was treated.
- Find sales with a similar unit. The search starts in the same kind of Pomona neighborhood: tract with tract, historic district with older blocks. Fannie Mae's section B4-1.3-05 allows that "An aged settled sale will qualify as a comparable," which matters when recent sales with a second unit are few.
- Set them beside sales without one. Similar houses on similar lots that sold without a unit show the other side of the comparison. The difference, adjusted for everything else that differs, is the market's response.
- State what the evidence shows, and its limits. The same section requires "a description of the ADU and analysis of any effect it has on the value or marketability of the subject property." Where the evidence is thin, the report says so.
The unit's area goes on its own line, not into the main house's square footage; whether an ADU is part of gross living area explains the rule and its exception. For Fannie Mae and Freddie Mac loans, the redesigned Uniform Residential Appraisal Report is mandatory for new reports submitted on or after November 2, 2026, and Freddie Mac's UAD 3.6 FAQ says "The URAR includes more detailed information about ADUs, such as size, condition, rooms, and location."
Rent, Pomona's rules and who decides
Many granny flats are rented. Whether a lender counts that rent is the lender's decision; Fannie Mae's guide refers to its section B3-3.8-01 for "the requirements that need to be satisfied in order to include rental income in qualifying." Pomona also runs a rent stabilization program, and the state's Tenant Protection Act applies to many rentals; an appraisal notes local rent rules as conditions affecting income, not as legal advice. When rent evidence is part of the assignment, a market rent analysis measures it from Pomona leases rather than listing asks.
The county line on the east side
Pomona's eastern edge meets Montclair, in San Bernardino County, at the Mills Avenue line. East Pomona tracts and west Montclair tracts can look alike and still sit under different assessors and school districts. A Montclair sale with a back unit can be used for an east Pomona house only when it is the better evidence, with the location difference explained.
What to have ready
- The permit, final sign-off and approved plans for the unit, and the year it was finished.
- Any preservation review papers, if the house is in a historic district.
- Notes on meters, address, entrance and parking, and access to the unit, with any tenant told in advance.
Next step
New construction and ADU appraisal describes the assignment for a Pomona lot with a granny flat, finished or planned. You can request an appraisal or call (909) 324-6122. The fee is set by the scope of the assignment and quoted before work begins, and it does not depend on the value.
Sources
- California Government Code section 66313, definitions (copy at california.public.law) (accessed November 6, 2026)
- California Government Code section 66314(d)(1), rental and conveyance of an ADU (copy at california.public.law) (accessed November 6, 2026)
- California State Board of Equalization, Letter To Assessors No. 2024/014, Accessory Dwelling Units (May 2, 2024) (accessed November 6, 2026)
- Fannie Mae Selling Guide B2-3-04, Special Property Eligibility Considerations (11/04/2026) (accessed November 6, 2026)
- Fannie Mae Selling Guide B4-1.3-05, Improvements Section of the Appraisal Report (06/04/2025) (accessed November 6, 2026)
- Freddie Mac, Uniform Appraisal Dataset (UAD) 3.6 and forms redesign FAQ (accessed November 6, 2026)
- California Bureau of Real Estate Appraisers, license lookup for Gordon Hall (accessed November 6, 2026)
Gordon Hall, California Certified Residential Real Estate Appraiser, BREA No. AR003877 (lookup: https://www2.brea.ca.gov/breasearch/faces/party/view.xhtml?id=23601). Reports are prepared in conformity with the Uniform Standards of Professional Appraisal Practice (USPAP). Nothing here is legal or tax advice; admissibility is always the court's decision.
Frequently asked questions
Is there a standard value for a granny flat in Pomona?
No. A California ADU generally cannot be sold apart from the main house under Government Code section 66314(d)(1), so there is no separate price for one. An appraisal compares Pomona houses that sold with a permitted second unit against similar houses that sold without one and reports what that difference shows for the property in question.
Is a Pomona house with a back unit an ADU property or a duplex?
It depends on what was permitted and how the property is built. For loans sold to Fannie Mae, Selling Guide section B2-3-04 says the classification is based on the property's characteristics, including separate utility meters, a unique postal address and whether the unit can be legally rented. The report states which it is before comparing sales.
Is a granny flat behind a Lincoln Park house compared with tract sales?
Not as a first choice. Lincoln Park, Wilton Heights and Hacienda Park hold older homes on older lots, and exterior changes there go through preservation review. A rear unit in one of those districts is weighed against sales of similar older Pomona houses, while a unit behind a postwar tract house is compared with similar tracts.
Will a lender use the rent from my Pomona granny flat?
That is the lender's decision under its own program rules; Fannie Mae's Selling Guide, for example, refers to section B3-3.8-01 for the requirements to include rental income. When rent evidence is part of the assignment, the appraiser documents market rent from Pomona leases and notes local rent rules as conditions, not legal advice.
