CondominiumResidential
21100 Gary Dr
CASTRO VALLEY, CA 94546
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.
Built 19803 floors62 units1,037–1,259 ft²
$29M
All units combinedThe sum of our current value estimates for every unit in the building — roughly what the whole building's homes are worth together.
$462K
Median unit valueThe middle unit value in this building by our estimate: half the units are worth more, half less.
$432
Median $/ft²The middle price per square foot across the building's units, by our current estimates. Useful for comparing units of different sizes.
-56.4%vs the Castro Valley ZIP median sale $/ft² ($989)
Sales Performance
—
Median sale (12 mo)The middle sale price among this building's units that sold in the last 12 months, from recorded deeds.
—
1-yr changeHow the building's median sale price over the last 12 months compares with the 12 months before that.
0
Sales (12 mo)Units in this building that sold in the last 12 months, from recorded arms-length deeds.
0.0%
Turnover (12 mo)The share of units that changed hands in the last 12 months. Around 4–6% a year is typical; much higher can signal investor churn or a wave of exits.
This building's own appreciationThe building's own appreciation: for every unit that sold twice (held over a year), we compute its yearly price change between the two sales and take the middle value. This is the cleanest read on how this specific building performs, because it compares each unit to itself.
+4.8%per yeartypical hold 7.2 yrsfrom 82 same-unit resales
Median sale price (yearly, all time)Every recorded arms-length sale in the building since records begin, grouped by year: the bars count sales and the line tracks the median price paid.MedianSales
19881993199820032009201620202025
Sale price per ft² (yearly, all time)The middle price per square foot across the building's units, by our current estimates. Useful for comparing units of different sizes.$/ft²
19881993199820032009201620202025
140 arms-length sales on record for this building.
Unit Mix & Floor PlansThe building's recurring floor plans, found by grouping units with identical beds, baths and square footage in county records. Larger groups are the building's standard layouts; leftover units have one-off sizes.
Every unit: size vs estimated valueEvery unit in the building as one dot: across is its size, up is our current value estimate, and color is its bedroom count. Vertical columns of dots are recurring floor plans; the height spread within a column shows how much floor, view and condition move prices for the same layout.
2 bd3 bd
2 bed
49 units$454K · $432/ft²
3 bed
13 units$524K · $428/ft²
Recurring floor plansThe building's recurring floor plans, found by grouping units with identical beds, baths and square footage in county records. Larger groups are the building's standard layouts; leftover units have one-off sizes.
2 bd · 2 ba · 1,056 ft²
25 units$452K · $428/ft²
2 bd · 2 ba · 1,050 ft²
10 units$456K · $434/ft²
2 bd · 2 ba · 1,037 ft²
5 units$480K · $463/ft²
3 bd · 2.5 ba · 1,218 ft²
4 units$527K · $433/ft²
3 bd · 2.5 ba · 1,232 ft²
4 units$528K · $428/ft²
2 bd · 2 ba · 1,070 ft²
3 units$454K · $424/ft²
3 bd · 2 ba · 1,245 ft²
3 units$518K · $416/ft²
One-off layouts
8 units
Value DistributionHow the building's units spread across value ranges by our current estimates. A wide spread usually means big differences in size, floor or view.
$393K–$393K
1 unit
$435K–$438K
6 units
$441K–$460K
23 units
$462K–$482K
11 units
$487K–$505K
8 units
$507K–$524K
5 units
$532K–$552K
6 units
$560K–$575K
2 units
Value by Floor & LineAverage estimated price per square foot by floor range, using unit numbers to infer floors. Higher floors usually price higher — the gap shows how much the view is worth here.
Floor 1
$436/ft²25 units · +1%
Floor 2
$435/ft²22 units · +1%
Floor 3
$435/ft²13 units · +1%
Unit lines by $/ft²Condo units stacked vertically share a unit line — the last digits of the unit number (like 05 in 1205, 1305, 1405). Lines share a layout and exposure, so comparing estimated $/ft² by line shows which position in the building commands a premium.
Line ·11
$456/ft²3 units · +6%
Line ·09
$452/ft²3 units · +5%
Line ·12
$444/ft²3 units · +3%
Line ·04
$437/ft²3 units · +1%
Line ·10
$435/ft²3 units · +1%
Line ·06
$434/ft²3 units · +1%
Line ·02
$434/ft²4 units · +1%
Line ·07
$432/ft²5 units · +0%
Line ·08
$426/ft²4 units · -1%
Line ·03
$423/ft²3 units · -2%
Line ·13
$418/ft²3 units · -3%
Line ·05
$416/ft²3 units · -4%
Ownership & Financing
Owner-occupiedThe share of units where the owner lives in the unit, per county records. The rest are second homes or rentals.82%
Company-ownedUnits owned through an LLC, trust, or other company — a rough proxy for investor ownership.23%
Typical owner tenureThe middle number of years since each unit last changed hands — how long the current owners have been in place.10.4 yrs
Cash purchases (5 yrs)The share of purchases in the last 5 years with no mortgage recorded. High cash share is common in second-home and investor buildings.9%
Avg. loan-to-valueAverage current loan balance against unit value across the building. Low numbers mean owners hold lots of equity — a sign of financial stability.51%
Median owner equityThe middle dollar amount of equity (value minus loans) unit owners hold in this building.$463,560
Median tax billThe middle annual property tax bill among the building's units.$6,000
Pre-foreclosure noticesUnits with an active pre-foreclosure or foreclosure notice on file.0
Recent SalesThe latest recorded arms-length sales in the building, newest first.
Unit 215Sep 4, 2025$426,000$403/ft²Unit 102Dec 20, 2024$530,000$505/ft²Unit 102Dec 20, 2024$530,000$505/ft²Unit 307Aug 19, 2024$558,000$528/ft²Unit 307Aug 19, 2024$558,000$528/ft²Unit 106Aug 28, 2023$540,000$521/ft²Unit 116Jun 2, 2022$645,000$614/ft²Unit 217May 5, 2022$635,000$601/ft²Unit 117May 4, 2022$655,000$610/ft²Unit 213Apr 18, 2022$698,000$561/ft²
Values are TopHap estimates, not appraisals. Sales, ownership and tax figures come from recorded county documents via ATTOM and can lag by several weeks.
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
Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.
MHE
Bret Harte Middle SchoolC-
Middle · Grades 7–8 · 1.5 mi
Hayward High SchoolC+
High · Grades 9–12 · 1.6 mi
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%
All UnitsEvery property record the county has at this street address, such as the units in a condo building. Prices shown are our estimates, not asking prices.
21100 Gary Dr # 101
3 bd · 2.5 ba · 1,218 ft²
21100 Gary Dr # 101
3 bd · 2.5 ba · 1,218 ft²
21100 Gary Dr # 102
2 bd · 2 ba · 1,050 ft²
21100 Gary Dr # 102
2 bd · 2 ba · 1,050 ft²
21100 Gary Dr # 103
2 bd · 2 ba · 1,050 ft²
21100 Gary Dr # 104
2 bd · 2 ba · 1,259 ft²
21100 Gary Dr # 105
3 bd · 2.5 ba · 1,232 ft²
21100 Gary Dr # 106
2 bd · 2 ba · 1,037 ft²
21100 Gary Dr # 107
2 bd · 2 ba · 1,050 ft²
21100 Gary Dr # 107
2 bd · 2 ba · 1,050 ft²
21100 Gary Dr # 108
2 bd · 2 ba
21100 Gary Dr # 108
2 bd · 2 ba · 1,050 ft²
21100 Gary Dr # 109
2 bd · 2 ba · 1,050 ft²
21100 Gary Dr
2 bd · 2 ba · 1,050 ft²
21100 Gary Dr # 111
2 bd · 2 ba · 1,037 ft²
21100 Gary Dr # 112
3 bd · 2.5 ba · 1,232 ft²
21100 Gary Dr # 113
3 bd · 2 ba · 1,245 ft²
21100 Gary Dr # 114
2 bd · 2 ba · 1,070 ft²
21100 Gary Dr # 115
2 bd · 2 ba · 1,037 ft²
21100 Gary Dr # 116
2 bd · 2 ba · 1,050 ft²
21100 Gary Dr # 117
2 bd · 1.5 ba · 1,073 ft²
21100 Gary Dr # 118
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 119
2 bd · 2 ba · 1,070 ft²
21100 Gary Dr # 120
2 bd · 2 ba · 1,037 ft²
21100 Gary Dr # 121
2 bd · 2 ba · 1,050 ft²
21100 Gary Dr # 122
2 bd · 1.5 ba · 1,063 ft²
21100 Gary Dr # 201
3 bd · 2.5 ba
21100 Gary Dr # 202
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 202
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 203
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 204
3 bd · 2 ba · 1,259 ft²
21100 Gary Dr # 205
3 bd · 2.5 ba · 1,232 ft²
21100 Gary Dr # 206a
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 207
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 208
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 209
2 bd · 2 ba · 1,070 ft²
21100 Gary Dr # 210
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 212
3 bd · 2.5 ba · 1,232 ft²
21100 Gary Dr # 213
3 bd · 2 ba · 1,245 ft²
21100 Gary Dr # 214
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 215
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 216
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 217
2 bd · 1.5 ba · 1,057 ft²
21100 Gary Dr # 218
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 219
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 220
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 221
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 222
2 bd · 1.5 ba · 1,047 ft²
21100 Gary Dr # 303
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 304
3 bd · 2 ba · 1,245 ft²
21100 Gary Dr # 305
3 bd · 2.5 ba · 1,218 ft²
21100 Gary Dr # 306
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 307
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 307
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 308
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 308
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 309
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 310
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 311
2 bd · 2 ba · 1,056 ft²
21100 Gary Dr # 312
3 bd · 2.5 ba · 1,218 ft²
21100 Gary Dr # 313
2 bd · 2 ba · 1,037 ft²
Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.
About 21100 Gary Dr
How many units are in 21100 Gary Dr, Castro Valley, CA?
21100 Gary Dr, Castro Valley, CA has 62 residential units across 3 floors, built in 1980, according to county assessor records.
What is a unit at 21100 Gary Dr, Castro Valley, CA worth?
The median TopHap Estimate across the 62 units at 21100 Gary Dr, Castro Valley, CA is $462,059. That works out to $432 per square foot. Units run from 1,037 to 1,259 square feet. Estimates are modelled from recorded sales and assessments, not appraisals.
Is 21100 Gary Dr, Castro Valley, CA expensive for Castro Valley?
Units at 21100 Gary Dr, Castro Valley, CA carry a median of $432 per square foot, 56% below the Castro Valley median of $989 per square foot.
How often do units sell at 21100 Gary Dr, Castro Valley, CA?
0 units at 21100 Gary Dr, Castro Valley, CA sold in the last 12 months, out of 140 recorded arms-length sales all time. That is a turnover rate of 0.0% of the building per year.
Have units at 21100 Gary Dr, Castro Valley, CA appreciated?
Across 82 repeat sales of the same unit, 21100 Gary Dr, Castro Valley, CA returned a median 4.8% per year. Because each pair is the same unit bought and sold, the figure is not distorted by which units traded. The median owner held for 7.2 years.
What floor plans does 21100 Gary Dr, Castro Valley, CA have?
The most common plan at 21100 Gary Dr, Castro Valley, CA is a 2-bedroom of 1,056 square feet, repeated 25 times, with a median estimate of $452,137. TopHap identifies 7 recurring plans in the building.
More homes on Gary Dr
- 21103 Gary Dr # 307d$447K2 bd · 2 ba · 1,025 ft² · Sold $450K · Sep 2026
- 21062 Gary Dr # 118$469K2 bd · 2 ba · 1,050 ft² · Sold $475K · Aug 2026
- 21103 Gary Dr # 116e$540K3 bd · 2 ba · 1,354 ft² · Sold $551K · Jul 2026
- 21109 Gary Dr # 203$471K2 bd · 2 ba · 1,041 ft² · Sold $484K · Jun 2026
- 21103 Gary Dr # 215a$552K2 bd · 2 ba · 1,393 ft² · Sold $570K · May 2026
- 21117 Gary Dr # 217$418K2 bd · 2 ba · 1,056 ft² · Sold $435K · Apr 2026
- 21117 Gary Dr # 119$495K2 bd · 2 ba · 1,070 ft² · Sold $515K · Apr 2026
- 21071 Gary Dr # 204$442K2 bd · 2 ba · 1,101 ft² · Sold $460K · Apr 2026
- 21239 Gary Dr # 206a$638K2 bd · 2 ba · 1,393 ft² · Sold $612K · Mar 2026
- 21117 Gary Dr # 106$400K1 bd · 1 ba · 798 ft² · Sold $418K · Mar 2026
- 21117 Gary Dr # 116$406K2 bd · 1 ba · 1,070 ft² · Sold $425K · Mar 2026
- 21228 Gary Dr # 105$523K3 bd · 2 ba · 1,276 ft² · Sold $550K · Feb 2026
Closest homes
- 21062 Gary Dr$452K0 ft · 2 bd · 2 ba · 1,056 ft² · Sold $225K · Nov 2010
- 21100 Gary Dr$475K0 ft · 2 bd · 2 ba · 1,056 ft² · Sold $558K · Aug 2024
- 21062 Gary Dr$543K0 ft · 3 bd · 2.5 ba · 1,232 ft² · Sold $640K · Sep 2022
- 21062 Gary Dr$380K0 ft · 1 bd · 1 ba · 798 ft² · Sold $323K · Jun 2016
- 21100 Gary Dr$444K0 ft · 2 bd · 2 ba · 1,056 ft² · Sold $296K · Nov 2013
- 21100 Gary Dr$450K0 ft · 2 bd · 2 ba · 1,050 ft² · Sold $287K · Jul 2002
- 21100 Gary Dr$446K0 ft · 2 bd · 2 ba · 1,056 ft² · Sold $385K · May 2023
- 21100 Gary Dr$467K0 ft · 2 bd · 2 ba · 1,050 ft² · Sold $530K · Dec 2024
More homes in Castro Valley 94546
- 4618 Ewing Rd$1.8M3 bd · 1.5 ba · 1,851 ft² · Sold $1.8M · Oct 2026
- 19453 Vaughn Ave$986K3 bd · 2 ba · 1,440 ft² · Sold $1.2M · Sep 2026
- 4315 Omega Ave$1.1M4 bd · 3 ba · 1,591 ft² · Sold $1.1M · Sep 2026
- 1540 Crescent Ave$799K2 bd · 2 ba · 1,122 ft² · Sold $800K · Sep 2026
- 16989 Brierly Ct$1.9M4 bd · 3.5 ba · 3,379 ft² · Sold $2.2M · Sep 2026
- 2500 Miramar Ave$489K2 bd · 2 ba · 1,133 ft² · Sold $429K · Sep 2026
- 3125 Alexis Pl$1.1M4 bd · 2.5 ba · 2,044 ft² · Sold $1.1M · Sep 2026
- 5223 Crane Ave$1.3M3 bd · 2 ba · 1,604 ft² · Sold $1.3M · Sep 2026
- 19961 Redwood Rd$915K2 bd · 1.5 ba · 1,257 ft² · Sold $1.8M · Sep 2026
- 18467 Clifton Way$1.4M5 bd · 3 ba · 2,460 ft² · Sold $431K · Sep 2026
- 17845 Center St$1.8M4 bd · 2.5 ba · 3,446 ft² · Sold $119K · Sep 2026
- 20927 Nunes Ave$924K3 bd · 2 ba · 1,539 ft² · Sold $925K · Sep 2026
Assigned schools
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