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CondominiumResidential
$551,215$453 / 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 Sep 24, 2026
Last sold for $8,900 on Aug 31, 2011

21100 GARY DR

CASTRO VALLEY, CA 94546
Building report
3
Beds
2.5
Baths
1,218 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.
3.11 ac
Lot SizeThe size of the land the home sits on, from county records.
1981
Year BuiltThe year the home was originally built, according to county records.
7
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.

Valuation

$551K
$522K low$581K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$8,900 · Aug 31, 2011

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$8,276 (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.$639,741 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$191,922
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$447,819
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$627,200
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$621,000

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Condominium
CountyALAMEDA
ConstructionThe main material the home's frame and walls are built from.Wood (Unspecified)
RoofThe main material covering the roof, such as asphalt shingle or tile.Tile
HeatingThe type of heating system in the home.Forced Air With Air Conditioning
GarageWhether the property has a garage, and details like whether it is attached to the home.Carport (Unspecified)
PoolWhether the property has a pool, and what kind, such as in-ground.No
ViewThe type of view from the property, or another feature of the site that affects value.Bay

Transaction History(10)

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

Foreclosure Filings(3)

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

M
Bret Harte Middle SchoolC-
Middle · Grades 7–8 · 1.5 mi
H
Hayward High SchoolC+
High · Grades 9–12 · 1.6 mi
E
Fairview Elementary SchoolD
Elementary · Grades KG–6 · 2.1 mi

District: Hayward 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

21100 Gary Dr 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 less than 93% of homes in Castro Valley 94546
  • Costs less per square foot than 91% of homes in Castro Valley 94546
  • Smaller than 75% of homes in Castro Valley 94546
  • Has a bigger lot than 97% of homes in Castro Valley 94546
  • Newer than 87% of homes in Castro Valley 94546

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
$453K$1.8M

This home is worth more than 7% 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$551,215
CheaperTypical $995,016Pricier

Pricier than 7% of homes nearby

Price per ft²$453
CheaperTypical $630Pricier

Pricier than 9% of homes nearby

Living area1,218 ft²
SmallerTypical 1,543 ft²Bigger

Bigger than 25% of homes nearby

Lot size3.11 ac
SmallerTypical 0.15 acBigger

Bigger than 97% of homes nearby

Year built1981
OlderTypical 1955Newer

Newer than 87% of homes nearby

How 21100 Gary Dr ranks against every home in each area.
MeasureThis homeHayward NorthCastro Valley 94546Alameda County
Estimated valuepricier than$551,21545% of homes7% of homes13% of homes
Price per ft²pricier than$45353% of homes9% of homes11% of homes
Living areabigger than1,218 ft²44% of homes25% of homes27% of homes
Lot sizebigger than3.11 ac84% of homes97% of homes97% of homes
Year builtnewer than198175% of homes87% of homes69% of homes

About 21100 Gary Dr

How much is 21100 Gary Dr, Castro Valley, CA worth?

The TopHap Estimate for 21100 Gary Dr, Castro Valley, CA is $551,215 as of Sep 24, 2026. The likely range is $521,750 to $580,680. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21100 Gary Dr, Castro Valley, CA last sell?

21100 Gary Dr, Castro Valley, CA last sold on Aug 31, 2011 for $8,900, according to the county's recorded deed. TopHap holds 7 recorded sales for this parcel.

How big is 21100 Gary Dr, Castro Valley, CA?

21100 Gary Dr, Castro Valley, CA has 3 bedrooms, 2.5 bathrooms and 1,218 square feet of living space.

When was 21100 Gary Dr, Castro Valley, CA built?

21100 Gary Dr, Castro Valley, CA was built in 1981, making it 45 years old.

What schools serve 21100 Gary Dr, Castro Valley, CA?

21100 Gary Dr, Castro Valley, CA is assigned to Bret Harte Middle School (middle), rated C-; Hayward High School (high), rated C+; Fairview Elementary School (elementary), rated D. All sit in Hayward Unified School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21100 Gary Dr, Castro Valley, CA compare to other homes in Castro Valley 94546?

Among the 13,473 homes in Castro Valley 94546, it is worth more than 7% of them ($551,215 against a typical $995,016), its price per square foot is higher than 9% of them ($453 against a typical $630), it is bigger than 25% of them (1,218 ft² against a typical 1,543 ft²), its lot is bigger than 97% of them (3.11 ac against a typical 0.15 ac) and it is newer than 87% of them (1981 against a typical 1955). Measured against all of Alameda County, it is worth more than 13% 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 21100 Gary Dr, Castro Valley, CA?

The 2025 property tax bill for 21100 Gary Dr, Castro Valley, CA was $8,276. The county assessed it at $639,741.

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