San Mateo County property record for 321 42nd Ave, San Mateo, CA 94403
| Property Type | Single Family Home |
|---|---|
| Details | 2 bd · 1 ba · 1,180 sqft · built 1949 |
| Lot Size | 0.135 acres (5,894 sqft) |
| Owner | Individual Name on File |
| Last Sale | $370,000 (Apr 1997) |
| Tax Bill | $9,297 (2025) |
| Deeds & Mortgages | May 2022 Transfer |
| Flood Zone | Zone X (minimal risk) |
| APN | 042-215-020 |
| Primary APN | 042-215-020 |
|---|
| Bedrooms | 2 Beds |
|---|---|
| Full Baths | 1 Bath |
| Total Rooms | 5 Rooms |
| Stories | 1 Story |
| Building Area | 1,180 sqft Living Area |
| 1st Floor Area | 1,180 sqft |
| Family Room | Family Room |
| Fireplaces | 1 Fireplace |
| Fireplace | Fireplace |
| Year Built | Built 1949 |
|---|---|
| Effective Year Built | Effective 1949 |
| Architectural Style | Ranch |
| Exterior Material | Wood |
| Construction Type | Wood |
| Roof Material | Wood Shingle |
| Lot Area | 5,894 sqft (0.135 acres) |
| Lot Dimensions | 90 ft deep x 68 ft wide |
| Garage Area | 240 sqft |
| Parking Spaces | 1 Parking Space |
| Cooling System | Central |
|---|---|
| Heating System | Central |
| Street Address | 321 42ND AVE |
|---|---|
| City | SAN MATEO |
| State | CA |
| Zip | 94403-5003 |
| Property Category | Residential |
| Property Type | Residential > Single Family > Home |
| Local Zoning Code | R10006 |
| Legal Description | LOT 32 BLOCK 25 SAN MATEO KNOLLS MAP NO 2 RSM 24/61 62 CITY OF SAN MATEO |
| Legal Subdivision | SAN MATEO KNOLLS MAP NO 2 |
| Legal Block | 25 |
| Legal Lot Number | 32 |
| Jurisdiction | SAN MATEO CA |
| Township / Civil Division | SAN MATEO |
| Census Block Group | 2 |
| Census Block | 2006 |
| Census Tract | 607100 |
321 42nd Ave is owned by an individual who acquired it in March 2022.
Source: San Mateo County records, as of July 15, 2026
| Owner of Record | Individual Name on File |
|---|---|
| Mailing Address | 3395 MICHELSON DR, 5347, IRVINE, CA 92612-3442 |
| Owner Type | Individual |
Owner names and exact recorded amounts are on file and can be viewed instantly on this page with a free 10-day trial.
| Deed Names | Name on Deed |
|---|---|
| Last Sale | Apr 15, 1997 · Amount on File |
| Deed Sale | Apr 15, 1997 · Amount on File |
| Deed Document Number | 199743158 |
| Last Transfer Date | Mar 18, 2022 |
| Transfer Doc | 0000043979 |
| Record Updated | Sep 20, 2026 |
| Document Type | Intrafamily Transfer |
|---|---|
| Jurisdiction | SAN MATEO CA |
| Recording Date | May 27, 2022 |
| Property Address | 321 42ND AVE, SAN MATEO, CA 94403-5003 |
| Document Number | 0000043979 |
| Map Reference | MB 24 PG 60-62 |
| Instrument Date | Mar 18, 2022 |
| Instrument | 2022-043979 |
| Transaction Type | Transfer |
| Record Updated | Jun 15, 2022 |
| Tax | $0.00 |
|---|---|
| Amount Accuracy | Transfer Tax Exempt |
| Additional |
|
| Name | Verified Name |
|---|
| Name | Verified Name |
|---|---|
| Address | 321 42ND AVE, SAN MATEO, CA 94403-5003 |
The 2025 property tax bill for 321 42nd Ave was $9,297.
Source: San Mateo County assessment roll, as of July 15, 2026
| Type | Name |
|---|---|
| State | California |
| County | San Mateo County |
| Municipality | San Mateo City |
| Elementary School District | San Mateo-Foster City Elementary School District (KG - 08) |
| Secondary School District | San Mateo Union High School District (09 - 12) |
| Year | Tax Bill | Assessed Value | Assessed Market Value |
|---|---|---|---|
| 2026 | $614,642 (+2%) Land $307,321 Building $307,321 | ||
| 2025 | $9,297.00 | $602,592 Land $301,296 Building $301,296 | |
| 2023 | $8,442.00 (-1.63%) | $579,196 Land $289,598 Building $289,598 | $1,405,530 |
| 2022 | $8,582.00 |
Assessed value and assessed market value are set for property tax purposes and are not market price estimates.
FEMA maps place 321 42nd Ave in Zone X, an area of minimal flood risk.
Source: FEMA National Flood Hazard Layer, effective September 10, 2026
| FEMA Flood Zone | Zone X minimal risk |
|---|---|
| Flood Insurance Requirement | Not required lenders may require it |
Values are read at the parcel center point; lenders make the official flood determination.
The area around 321 42nd Ave has no burnable land within ember reach, so its wildfire risk is not rated.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | Not rated no burnable land within ember reach |
|---|
Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.
Source: EPA Safe Drinking Water Information System, as of September 2026
| Water System | CALIFORNIA WATER SERVICE - SAN MATEO private · serves 103,536 people · EPA ID CA4110008 |
|---|---|
| Water Source | Purchased surface water from SAN FRANCISCO REGIONAL WATER SYSTEM |
| Last State Inspection | Mar 2025 |
| Lead | 4 ppb (2023–2025) action level 15 ppb |
| Water Quality | None last 10 years |
|---|---|
| Treatment and Procedure | None last 10 years |
| Monitoring and Reporting | None last 3 years |
Results are for the whole water system, not water tested at this address; lead at the tap also depends on the building's own pipes.
Source: FCC Broadband Data Collection, based on 785 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| Sonic Telecom Fiber | 10,000 / 10,000 |
| AT&T Fiber · Fixed Wireless, DSL in parts of the area | 5,000 / 5,000 |
| Xfinity Cable | 2,000 / 250 |
| Astound Broadband Cable | 1,500 / 50 |
| Verizon Fixed Wireless | 300 / 20 |
| Etheric Networks Fixed Wireless | 250 / 100 |
May also be available: GeoLinks, T-Mobile.
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