28 Walnut Ave, Atherton, CA 94027 Property Records

San Mateo County property record for 28 Walnut Ave, Atherton, CA 94027

Property Summary

Property Type	Single Family Home
Details	4 bd · 3 ba · 2,030 sqft · built 1955
Lot Size	0.15 acres (6,550 sqft)
Owner	2 Company Names on File
Last Sale	$1,175,000 (Nov 2011)
Tax Bill	$19,058 (2025)
Deeds & Mortgages	Jun 2019 Mortgage
Flood Zone	Zone X (minimal risk)
APN	`060-332-140`

Property Details

APN / Parcel Number

Primary APN	`060-332-140`

Interior

Bedrooms	4 Beds
Full Baths	3 Baths
Total Rooms	9 Rooms
Stories	1 Story
Building Area	2,030 sqft Living Area
1st Floor Area	1,590 sqft
Family Room	Family Room
Study	Study

Exterior

Year Built	Built 1955
Effective Year Built	Effective 1955
Lot Area	6,550 sqft (0.15 acres)
Lot Dimensions	131 ft deep x 50 ft wide

Utilities, Heating & Cooling

Cooling System	Central
Heating System	Central

Location & Zoning

Street Address	28 WALNUT AVE
City	ATHERTON
State	CA
Zip	94027-3821
Property Category	Residential
Property Type	Residential > Single Family > Home
Local Zoning Code	R1001A
Legal Description	LOT 7 BLOCK B MENLO PARK VILLA LOTS RSM 1/93 TOWN OF ATHERTON
Legal Subdivision	MENLO PARK VILLA
Legal Block	B
Legal Lot Number	7
Jurisdiction	SAN MATEO CA
Township / Civil Division	SAN MATEO
Census Block Group	2
Census Block	2024
Census Tract	611500

Owner

Source: San Mateo County records · APN 060-332-140

Assessment roll updated July 15, 2026 · Last verified July 2026

Owner names and exact recorded amounts shown locked on this page are available instantly with a free trial.

Owner of Record	2 Company Names on File
Mailing Address	28 WALNUT AVE, ATHERTON, CA 94027-3821
Occupancy	Owner Occupied
Owner Type	Company
Vesting	Trust

Deeds, Mortgages & Sale History

Assessor's Deed Record

Deed Names	2 Verified Names on Deed
Last Sale	Nov 04, 2011 · Amount on Record
Deed Sale	Nov 04, 2011 · Amount on Record
Deed Document Number	2011132696
Last Transfer Date	May 09, 2019
Transfer Doc	0000043532
Record Updated	Sep 20, 2026

June 2019: Intrafamily Transfer, Transfer

Document Type	Intrafamily Transfer
Jurisdiction	SAN MATEO CA
Recording Date	Jun 07, 2019
Property Address	28 WALNUT AVE, ATHERTON, CA 94027-3821
Document Number	0000043532
Map Reference	MB 6 PG 295
Instrument Date	May 09, 2019
Instrument	2019-043532
Transaction Type	Transfer
Record Updated	Aug 05, 2022
Title Company	FIDELITY NATIONAL TITLE CO

Transaction

Tax	$0.00
Amount Accuracy	Transfer Tax Exempt
Additional	Intrafamily Transfer

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Family Trust
Address	28 WALNUT AVE, ATHERTON, CA 94027-3821

Mortgage

Document Number	0000043533
Date	Jun 07, 2019
Instrument	2019-043533

Lender

Name	UBS BANK USA
Type	Bank

Agreement

Type	ARM
Amount	Amount Recorded
Term	361 Months
Due	Jul 01, 2049

Interest

Rate Type	Adjustable Rate
Rate	2.87%
Adjustable	Adjustable Rate Rider
Type Change Date	Jul 01, 2026
Change Frequency	Annually
Min Rate At Change	2.25%
Max Rate At Change	7.87%
Index	1-Year LIBOR
Max Rate	7.87%

Tax Assessment & Valuation

Source: San Mateo County records · Assessment roll updated July 15, 2026 · Last verified July 2026

Property Jurisdictions

Type	Name
State	California
Municipality	Atherton Town
County	San Mateo County
Elementary School District	Menlo Park City Elementary School District (KG - 08)
Secondary School District	Sequoia Union High School District (09 - 12)

Tax Bill & Assessment History

Assessed value and assessed market value are set for property tax purposes and are not market price estimates.

Year	Tax Bill	Assessed Value	Assessed Market Value
2026		$1,505,367 (+2%) Land $1,345,229 Building $160,138
2025	$19,058.00 (+5.16%) Homeowner's exemption	$1,475,851 (+4.04%) Land $1,318,852 Building $156,999
2023	$18,122.00 (+2.52%) Homeowner's exemption	$1,418,544 Land $1,267,641 Building $150,903	$1,465,650
2022	$17,677.00

Flood & Wildfire

Source: FEMA National Flood Hazard Layer as of September 10, 2026 · FEMA NFIP claims and policies as of September 2026 · USDA Forest Service Wildfire Risk to Communities as of 2024 · Last verified October 2026

Flood

FEMA Flood Zone	Zone X minimal risk
Flood Insurance Requirement	Not required lenders may require it
Nearby Flood Policies	4 in force

Wildfire

Wildfire Risk	Low lower than 99.1% of the US · lower than 99.2% of California
Wildfire Likelihood	Under 0.01% annual chance
Exposure	None beyond ember reach

Values are read at the parcel center point; flood claims are located to the census block group, not this parcel; lenders make the official flood determination.

Internet Providers

Source: FCC Broadband Data Collection as of December 31, 2025 · Last verified October 2026

Provider	Max Down / Up (Mbps)
Race Telecommunications Fiber	10,000 / 10,000
Xfinity Cable	2,000 / 250
AT&T Fixed Wireless · DSL · Fiber in parts of the area	100 / 20

May also be available: California Internet, Etheric Communications, LLC., T-Mobile USA.

Based on FCC filings for 283 locations within half a mile of this property.

Drinking Water

Source: EPA Safe Drinking Water Information System as of 2026 Q3 · EPA water system boundaries as of March 2026 · Last verified October 2026

Water System	CALIFORNIA WATER SERVICE - BEAR GULCH private · serves 60,382 people
Water Source	Surface water
Last State Inspection	Feb 2025
Lead	4 ppb (2022–2024) action level 15 ppb

Violations Reported to EPA

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 as reported to EPA, not water tested at this address; lead at the tap also depends on the building's own pipes. The full violation and enforcement history is in the system's EPA record.