A buyer making an offer on a San Mateo condo this fall has to get two things approved. One is the buyer's own loan file. The other is the homeowners association behind the unit: its budget, its reserves, its insurance and, in qualifying buildings, the balcony inspection report California law requires. Single-family sales skip that second step entirely. Over the past three months, that step has done more than interest rates to separate the speed of the two markets.
The headline median blends the two together. Split them apart and you get one market where condos sit for weeks and another where houses go into contract in about two.
The September Numbers, Split by Property Type
The most recent monthly report from the San Mateo County Association of Realtors covers September 2026 and was released October 9. It shows two markets inside one city.
| San Mateo, September 2026 | Single-family homes | Condos and townhomes |
|---|---|---|
| Median sale price | $2,175,000 | $1,064,000 |
| Median price per square foot | $1,305 | $790 |
| Average days on market | 14 | 41 |
| Percent of list price received | 107% | 100% |
| Homes in inventory | 39 | 85 |
| Sales closed | 44 | 24 |
| Months of inventory | 0.9 | 3.4 |
San Mateo's 85 condo listings were the most of any city in the county, close to a third of the 276 attached homes for sale countywide. The September condo median looks strong, but it rests on just 24 sales. It also swung from $975,000 in July to $845,000 in August before reaching $1,064,000. With so few sales, the median says little. Supply tells a clearer story. Condo inventory went from 65 in July to 68 in August to 85 in September, and months of inventory rose from 2.5 to 2.7 to 3.4. Single-family inventory also rose, from 26 to 39, yet still came in under one month of supply.
A house at 0.9 months of supply and 107% of list sells to whoever writes the strongest offer. A condo at 3.4 months and 100% of list sells to a buyer whose lender approves the building. Those are different problems, and the second one has become harder.
The Rule Changes That Landed This Summer
In March 2026, Freddie Mac published Bulletin 2026-C, which changed how lenders review established condominium projects. Most of the changes apply to loans with application dates on or after August 3, 2026, just as San Mateo's condo inventory began to rise.
- Streamlined Review retired. Freddie Mac's lighter Streamlined Review is gone. Established projects now go through the full Established Condominium Projects review, Reciprocal Review or, where eligible, an exemption.
- Highest reserve number required. If the HOA has a reserve study, its budget must include the study's highest recommended reserve allocation. That figure can't come from "baseline" funding, a method where the reserve balance approaches zero without falling below it.
- Higher minimum reserves from January 4, 2027. For applications on or after that date, the minimum reserve allocation rises from 10% to 15% of the HOA's annual budgeted assessment income.
- Unit-owner insurance. In a Fannie Mae lender letter dated March 18, 2026, Fannie Mae requires borrowers to carry an individual unit-owner policy whenever the building's master policy leaves out unit interiors or improvements or has a per-unit deductible. The rule applies to applications dated on or after July 1, 2026.
These rules affect timing alone. Nothing here shows they caused the September inventory increase. Still, the summer the condo market slowed is the same summer the federal standards for HOA finances got stricter. Every San Mateo condo financed with a conforming loan is now being judged against them.
The Packet That Now Matters as Much as the Floor Plan
Under Fannie Mae's full review, the lender examines the project's documents, enters project data into Fannie Mae's Condo Project Manager and certifies that the project is eligible. A project marked "Unavailable" cannot back a loan that Fannie Mae will buy. A buyer of a San Mateo condo is in effect asking whether the building passes these checks:
- Delinquencies. No more than 15% of units can be 60 or more days behind on regular HOA dues. The same cap applies separately to each special assessment.
- Reserve study. It has to be current and independent, covering the major common components, their condition and remaining life, repair costs, contributions, reserve balances and a funding plan.
- Master insurance. The HOA's master policy must insure project improvements for at least 100% of replacement cost, and Fannie Mae treats the premium as a common expense paid through dues.
- Balcony inspection report, in qualifying buildings. Under California Civil Code §5551, condo associations must visually inspect the exterior elevated elements they are responsible for at least once every nine years, with the first inspection due by January 1, 2025. SB 410, signed October 10, 2025, adds the most recent inspection report to the documents a seller must give a buyer. It also applies the inspection rules to buildings with three or more attached multifamily units.
FHA financing works on a parallel track. HUD insures condo loans in FHA-approved projects. In projects without approval, it allows Single-Unit Approval for completed projects of at least five units, which still tests insurance, owner occupancy and the project's finances. The Single-Unit Approval document checklist calls for a signed condo questionnaire covering owner occupancy, investor concentration, delinquencies, reserves, dues and special assessments, along with the budget, financial statements and insurance documents.
Each item is another document to request, read and send back. That accounts for some of the difference between 14 days and 41.
Why the Age of San Mateo's Condo Stock Raises the Stakes
San Mateo's best-known attached communities span several eras of construction. Woodlake began as an apartment complex and became condominiums in 1987. Its association now oversees roughly 900 condos and 66 townhomes. Harbortown, built around a lake, dates to 1979, and Edgewater Isle to 1984. The City's draft Housing Element dates Bridgepointe Condominiums to 1999.
None of these dates says anything about the condition of any particular association. They explain why the reserve study counts for so much here. Roofs, balconies, waterproofing and other common components age on a schedule. A budget that must now carry the reserve study's highest recommended allocation puts that schedule into the monthly dues. In its March 2026 lender letter, Fannie Mae warns that underfunded reserves can lead to unexpected special assessments or higher regular dues.
One deadline causes recurring confusion. California extended a balcony inspection deadline to January 1, 2026, but AB 2579 covers apartment buildings and expressly excludes common-interest developments. For condos, §5551 still lists January 1, 2025 as the first inspection deadline.
What the Local Reporting Adds
The San Mateo Daily Journal reported this spring on the countywide split between condos and single-family homes. It pointed to new multiunit supply competing with condos, condo owners' greater sensitivity to interest rates, and rising HOA dues and insurance premiums weakening many associations' finances. An agent quoted in the story put the financing link plainly:
"Lots of HOA reserves are below funding guidelines, and lenders require a certain amount of health from HOAs, and if those numbers fall below that, it becomes difficult to finance those properties."
The regional record shows how that plays out. In March 2025, the Mercury News reported 168 Bay Area condo projects on Fannie Mae's unavailable list. The names were not released, and the reasons ranged from insurance and maintenance to structural condition and reserves. Its examples came from outside San Mateo County. One San Pablo seller lost three buyers to lender declines before the property went into foreclosure.
What the Slack Means on Each Side of the Deal
For a buyer, the September numbers mean more time. At 41 average days on market and 100% of list price received, San Mateo's condo market gives a buyer room to read the HOA packet before committing, which the single-family market at 107% of list rarely allows. At $790 a square foot against $1,305, a condo buyer gets more space per dollar. Part of that discount pays for taking on the building's finances, and the monthly dues are where those finances show up.
For a seller, the gap tells you who the competition is. Condos in the same price range are mostly competing with each other, among 85 listings, and the ones that close sooner tend to have their HOA documents ready before the listing goes live. This is where operational preparation pays off. Ordering the association documents, reading the reserve study and pulling the latest elevated-element inspection report early keeps a buyer's lender from finding the surprises first.
Supply is also coming. San Mateo's approved Concar Drive plan includes 139 for-sale townhomes, three stories with three and four bedrooms, among 847 total units. Construction is targeted for 2027, pending approval of construction documents.
Quick Answers
Does the SB 326 report affect every San Mateo condo sale? The inspection rules apply to association-maintained elevated elements in qualifying condo buildings. SB 410 puts the most recent report into the seller's disclosure documents starting in 2026.
What changes on January 4, 2027? Freddie Mac's minimum reserve allocation rises from 10% to 15% of an HOA's annual budgeted assessment income, for loan applications received on or after that date.
Is FHA financing possible in a project that isn't FHA-approved? HUD offers Single-Unit Approval for completed projects of at least five units, subject to its own review of the project.
This post is general information, not legal, tax or financial advice. Confirm how these rules apply to your own purchase or sale with your lender, attorney or tax professional.
If you own a condo or townhome in San Mateo, your HOA packet affects your sale price as much as your square footage does. Real Smart Group can review your association documents with you before you list and give you a valuation based on current San Mateo condo comps, not the citywide median. Get your free home valuation.
