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Single Family ResidenceResidential
$1,559,883$550 / ft²
TopHap EstimateOur estimate of what this home would sell for today, based on nearby sales, the home's size and features, and local price trends. It is a starting point, not an appraisal.· confidence 95How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Aug 30, 2026
Last sold for $736,500 on Jun 11, 2010

18639 ALCORN PL

CASTRO VALLEY, CA 94546
4
Beds
3.5
Baths
2,837 ft²
Living AreaTotal finished area of the structures, from county records. Some counties include shared space like hallways or a building gym, so it may not match a listing.
0.18 ac
Lot SizeThe size of the land the home sits on, from county records.
2010
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.
9
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.
3
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$1.6M
$1.5M low$1.6M high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$736,500 · Jun 11, 2010

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$12,459 (2025)
Assessed ValueThe value the county assigns to this home to calculate property tax. It is often lower than what the home would sell for.$1,001,932 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$290,692
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$718,240
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$982,152
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$1,445,670

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountyALAMEDA
Lot (acres)The size of the land the home sits on, from county records.0.18
ConstructionThe main material the home's frame and walls are built from.Wood (Unspecified)
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(1)

Sales and refinances filed with the county for this home. Not every transfer is a normal sale, so check the type before comparing prices.

Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.

H
Castro Valley High SchoolA
High · Grades 9–12 · 0.5 mi
E
Proctor Elementary SchoolA+
Elementary · Grades KG–5 · 0.5 mi
M
Creekside Middle SchoolA+
Middle · Grades 6–8 · 1.0 mi

District: Castro Valley Unified School District

Neighborhood · ZIP 94546These are comparison scores, not percentages. 100 equals the national average, so 150 means about 50% above average.

CrimeLocal crime compared with the rest of the country, where 100 is average. It reflects things like population density, income, and how crime gets reported.78
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.91
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.657

Index scale: 100 = US average (tick). Lower is better.

Homes occupiedThe share of homes here that someone lives in. The rest sit empty, including vacation and for-sale homes.96%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.27%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.8.9%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.3%
PopulationHow many people live in this area.46,776
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.4,466 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$117,352
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$142,642
Average tempThe average temperature here across a full year.57°F
Annual precipHow much rain and melted snow falls here in a typical year.23 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.78%

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Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.

How this home compares

18639 Alcorn Pl measured against every home in its neighborhood, its ZIP code and its county, using county assessor records refreshed nightly. A home can stand out in one of those areas and look ordinary in another, because each one holds a different mix of homes.

  • Worth more than 95% of homes in Castro Valley 94546
  • Costs less per square foot than 76% of homes in Castro Valley
  • Bigger than 92% of homes in Castro Valley 94546
  • Has a bigger lot than 70% of homes in Alameda County
  • Newer than 98% of homes in Castro Valley

What homes are worth in Castro Valley 94546

Each bar is how many homes fall in that price range. The marker is this home.

This home
$456K$1.8M

This home is worth more than 95% of homes in Castro Valley 94546.

How it measures up in Castro Valley 94546

The dot is this home. The mark in the middle is the typical home in Castro Valley 94546.

Estimated value$1,559,883
CheaperTypical $977,150Pricier

Pricier than 95% of homes nearby

Price per ft²$550
CheaperTypical $620Pricier

Pricier than 30% of homes nearby

Living area2,837 ft²
SmallerTypical 1,551 ft²Bigger

Bigger than 92% of homes nearby

Lot size0.18 ac
SmallerTypical 0.16 acBigger

Bigger than 62% of homes nearby

Year built2010
OlderTypical 1955Newer

Newer than 98% of homes nearby

How 18639 Alcorn Pl ranks against every home in each area.
MeasureThis homeCastro ValleyCastro Valley 94546Alameda County
Estimated valuepricier than$1,559,88387% of homes95% of homes78% of homes
Price per ft²pricier than$55024% of homes30% of homes27% of homes
Living areabigger than2,837 ft²91% of homes92% of homes89% of homes
Lot sizebigger than0.18 ac65% of homes62% of homes70% of homes
Year builtnewer than201098% of homes98% of homes93% of homes

About 18639 Alcorn Pl

How much is 18639 Alcorn Pl, Castro Valley, CA worth?

The TopHap Estimate for 18639 Alcorn Pl, Castro Valley, CA is $1,559,883 as of Aug 30, 2026. The likely range is $1,485,350 to $1,634,416. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 18639 Alcorn Pl, Castro Valley, CA last sell?

18639 Alcorn Pl, Castro Valley, CA last sold on Jun 11, 2010 for $736,500, according to the county's recorded deed.

How big is 18639 Alcorn Pl, Castro Valley, CA?

18639 Alcorn Pl, Castro Valley, CA has 4 bedrooms, 3.5 bathrooms, 2,837 square feet of living space and a 0.18-acre lot.

When was 18639 Alcorn Pl, Castro Valley, CA built?

18639 Alcorn Pl, Castro Valley, CA was built in 2010, making it 16 years old. The building has 2 stories.

What schools serve 18639 Alcorn Pl, Castro Valley, CA?

18639 Alcorn Pl, Castro Valley, CA is assigned to Castro Valley High School (high), rated A; Proctor Elementary School (elementary), rated A+; Creekside Middle School (middle), rated A+. All sit in Castro Valley Unified School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 18639 Alcorn Pl, Castro Valley, CA compare to other homes in Castro Valley 94546?

Among the 13,469 homes in Castro Valley 94546, it is worth more than 95% of them ($1,559,883 against a typical $977,150), its price per square foot is higher than 30% of them ($550 against a typical $620), it is bigger than 92% of them (2,837 ft² against a typical 1,551 ft²), its lot is bigger than 62% of them (0.18 ac against a typical 0.16 ac) and it is newer than 98% of them (2010 against a typical 1955). Measured against all of Alameda County, it is worth more than 78% of homes there. These shares are recounted nightly from the full county assessor record for each area, not from active listings.

What are the property taxes on 18639 Alcorn Pl, Castro Valley, CA?

The 2025 property tax bill for 18639 Alcorn Pl, Castro Valley, CA was $12,459. The county assessed it at $1,001,932.

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