ACS 2021 release
2017-2021 five-year estimate
- Median home value B25077
- $2,000,001Margin of error not available
- Median gross rent B25064
- $3,501Margin of error not available
- Population B01003
- 6,582Margin of error ±420
Rental market · ZIP 94028 · Portola Valley, CA
ZIP 94028, Portola Valley, CA rental market
Population 6,531 · Portola Valley, San Mateo County, CA · ZIP Code Tabulation Area
Profile · ACS 2024 5-year
Not ranked
This ZIP Code area does not meet the ranking eligibility criteria; the figures below are shown as available.
It stays searchable; available government estimates remain below (data tier: Profile).
Key metrics
6,531
Population
±600 ±9.2% tight
$2,000,001
Median home value (ACS, owner-reported)
Direct ACS estimate: the Census Bureau publishes no margin of error for it
$3,501
Median gross rent (ACS, incl. utilities)
Direct ACS estimate: the Census Bureau publishes no margin of error for it
2.1%
Survey gross-rent yield (proxy)
Derived from ACS estimates: no published margin of error
$250,001
Median household income
Direct ACS estimate: the Census Bureau publishes no margin of error for it
0.0%
Rental vacancy
Derived from ACS estimates: no published margin of error
18.1%
Renter share
Derived from ACS estimates: no published margin of error
0.5%
Estimated property-tax burden
Derived from ACS estimates: no published margin of error
1965
Median year built
±2 years margin in years; a share of a year number would not mean anything
5.5%
Multifamily (5+ units)
Derived from ACS estimates: no published margin of error
Market context
Trend context
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View source data
Each point is one ACS 5-year estimate on the same 2020-Census ZCTA boundary. Adjacent releases overlap, so the release-to-release differences are not independent annual market movement.
| Series | 2017–2021 | 2018–2022 | 2019–2023 | 2020–2024 |
|---|---|---|---|---|
| Median home value B25077 | $2,000,001 | $2,000,001 | $2,000,001 | $2,000,001 |
| Median gross rent B25064 | $3,501 | $3,501 | $3,501 | $3,501 |
| Population B01003 | 6,582 ±420 | 6,888 ±693 | 6,645 ±633 | 6,531 ±600 |
ACS 2022 release
2018-2022 five-year estimate
- Median home value B25077
- $2,000,001Margin of error not available
- Median gross rent B25064
- $3,501Margin of error not available
- Population B01003
- 6,888Margin of error ±693
ACS 2023 release
2019-2023 five-year estimate
- Median home value B25077
- $2,000,001Margin of error not available
- Median gross rent B25064
- $3,501Margin of error not available
- Population B01003
- 6,645Margin of error ±633
ACS 2024 release
2020-2024 five-year estimate
- Median home value B25077
- $2,000,001Margin of error not available
- Median gross rent B25064
- $3,501Margin of error not available
- Population B01003
- 6,531Margin of error ±600
Source: U.S. Census Bureau, American Community Survey 5-year, table-based Summary File (ZCTA geography); tables B25077 (median value), B25064 (median gross rent), and B01003 (population); estimate + margin of error. Missing releases remain gaps and are never interpolated. Home value is owner-reported; gross rent describes renter housing stock; population is a ZCTA estimate. Dollar figures are nominal.
Measured market data
Measured observations for this ZIP Code, published beside the government survey figures above rather than replacing them. They measure different things and will legitimately disagree; the reconciliation below states on which axis, one axis at a time, instead of leaving a reader to guess. ZORI does not correct the ACS rent; neither is a better version of the other. Monthly series, revised in recent months, observed 2026-08, not live.
| Figure | ACS survey estimate | Zillow measured index |
|---|---|---|
| Typical home value | $2,000,001no published margin of error | $4,267,312no published margin of error |
| Methodology typical home value | The median of what owners themselves estimate their own home to be worth, across owner-occupied homes only. | A smoothed index of the typical value of homes in the middle tier (35th to 65th percentile) of the local stock, whether or not they sold. |
| Source | U.S. Census Bureau, American Community Survey 5-year estimates. | Zillow Economic Research public research data. |
| Vintage | ACS 2024 5-year: one estimate pooled over 2020–2024. Restated once a year, not monthly, and adjacent releases overlap. | Monthly series, observed 2026-08 and revised in recent months. Not live. |
| Geography | 2020 Census ZIP Code Tabulation Area 94028. | USPS ZIP code 94028: a related, but not identical, area. |
| Zillow Home Value Index (ZHVI, mid tier) | $4,267,312 |
|---|---|
| ZHVI bottom tier (5th–35th pct) | $3,034,840 |
| ZHVI top tier (65th–95th pct) | $6,376,662 |
| Market heat index | 111 |
| For-sale inventory | 17 |
| New listings | 4 |
| Measured 3-yr value growth | 6.17%/yr |
| Measured 5-yr value growth | 4.32%/yr |
| Measured 10-yr value growth | 4.14%/yr |
| ZHVI, 2-bedroom | $2,419,068 |
| ZHVI, 3-bedroom | $3,654,132 |
| ZHVI, 4-bedroom | $4,578,697 |
| ZHVI, 5-bedroom | $5,898,565 |
Source: Zillow Economic Research public research data, observation month 2026-08. Zillow keys on USPS ZIP codes; this page is a 2020 Census ZCTA, related but not identical geographies, so a Zillow value is matched to this ZCTA by code and is not a statement that the two areas are the same. Zillow is not affiliated with, and does not endorse, Compounding Estates.
Underwrite with these as starting points
Opening a calculator pre-loads the ACS median owner value and median gross rent as a survey-level starting point; every calculator input is editable. Owner-occupied median value and renter median gross rent describe different housing stock: the median-valued home is not the typical rental, so this is a screen, not a listing, appraisal, asking rent, cap rate, or forecast. Bring your own entry price and rent.
Evidence, sources & limitations
Official geography: Portola Valley town, San Mateo County. Analytical entity: the U.S. Census ZIP Code Tabulation Area (ZCTA) 94028, an approximation of the USPS ZIP delivery area, not its exact route boundaries. Model z3-measured-v1; data ACS 2024 5-year.
This ZIP Code area is primarily in San Mateo County (spans multiple counties), overlapping Portola Valley and other places, by land-area overlap from the official Census 2020 ZCTA relationship files (not population or address share).
| Population | survey ACS B01003 · ±9.2% margin of error |
|---|---|
| Median home value (ACS, owner-reported) | survey ACS B25077 · no published margin of error |
| Median gross rent (ACS, incl. utilities) | survey ACS B25064 · no published margin of error |
| Survey gross-rent yield (proxy) | derived 12 * ACS B25064 / B25077 · no published margin of error |
| Median household income | survey ACS B19013 · no published margin of error |
| Rental vacancy | derived ACS B25004 E002 / (B25003 E003 + B25004 E002) · no published margin of error |
| Renter share | derived ACS B25003 E003/E001 · no published margin of error |
| Estimated property-tax burden | derived ACS B25103 / B25077 · no published margin of error |
| Median year built | survey ACS B25035 · ±<1% margin of error |
| Multifamily (5+ units) | derived ACS B25024 (5+ unit structures / total) · no published margin of error |
Class: survey = ACS estimate (with margin of error); derived = computed from ACS. The survey gross-rent yield is a proxy (renter gross rent vs owner-occupied value, different housing stock; ACS top-codes very high values/rents) and is not a cap rate. Subscores are national percentiles among data-eligible areas; ranks are competition-ranked with deterministic ties. No vendor, listing, parcel, or school data. Not investment advice.