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Single Family ResidenceResidential
$4,198,414$536 / 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 84How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Oct 21, 2026
Last sold for $2,250,000 on Mar 24, 2020

512 HEMME AVE

ALAMO, CA 94507
10
Beds
7
Baths
7,833 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.
1.44 ac
Lot SizeThe size of the land the home sits on, from county records.
1930
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.
18
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.
2
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$4.2M
$3.5M low$4.9M high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$2,250,000 · Mar 24, 2020

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$27,952 (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.$2,509,913 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$1,505,948
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$1,003,965
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$2,460,700

Climate Risk

Overall riskThe average of the five hazard scores below, on a 0 to 100 scale. Higher means greater projected risk over the coming decades.55
86
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
85
WildfireProjected wildfire risk, scored 0 to 100, based on how much land burns in a typical year. Higher is riskier.
39
HeatProjected heat risk, scored 0 to 100, based on how many extremely hot days a year are expected. Higher is riskier.
51
StormProjected risk from heavy rainstorms, scored 0 to 100, based on how often extreme rainfall is expected. Higher is riskier.
14
DroughtProjected water shortage risk, scored 0 to 100. Higher means more strain on the local water supply.
Projected Flood DepthHow deep a serious flood is expected to get here at some point in the next 30 years. Shown in inches.91 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.34%
FEMA Flood ZoneFEMA's flood zone for this address. Zones starting with A or V are high risk, and lenders usually require flood insurance there.1 percent flood zone

Scores 0–100; higher = greater projected risk.

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountyCONTRA COSTA
Effective Year BuiltAn adjusted build year that accounts for condition and major remodels. A big renovation can make a home count as newer than it is.1995
CoolingThe type of cooling or air conditioning in the home.Central
GarageWhether the property has a garage, and details like whether it is attached to the home.Garage, Attached
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(5)

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.

E
Rancho Romero Elementary SchoolA+
Elementary · Grades KG–5 · 0.3 mi
M
Stone Valley Middle SchoolA
Middle · Grades 6–8 · 1.4 mi
H
San Ramon High SchoolA
High · Grades 9–12 · 1.7 mi

District: San Ramon Valley Unified School District

Neighborhood · ZIP 94507These 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.48
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.88
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.567

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.97%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.44%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.3.8%
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.13,817
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.1,241 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$216,734
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$278,668
Average tempThe average temperature here across a full year.58°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

512 Hemme Ave 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.

  • Among the most valuable homes in Contra Costa County
  • Costs less per square foot than 97% of homes in Alamo 94507
  • Among the largest homes in Alamo 94507
  • Has a bigger lot than 98% of homes in Contra Costa County
  • Among the oldest homes in Alamo 94507

What homes are worth in Alamo 94507

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

This home
$1M$5M

This home is worth more than 95% of homes in Alamo 94507.

How it measures up in Alamo 94507

The dot is this home. The mark in the middle is the typical home in Alamo 94507.

Estimated value$4,198,414
CheaperTypical $2,436,554Pricier

Pricier than 95% of homes nearby

Price per ft²$536
CheaperTypical $780Pricier

Pricier than 3% of homes nearby

Living area7,833 ft²
SmallerTypical 3,113 ft²Bigger

Bigger than almost all homes nearby

Lot size1.44 ac
SmallerTypical 0.5 acBigger

Bigger than 94% of homes nearby

Year built1930
OlderTypical 1977Newer

Older than almost all homes nearby

How 512 Hemme Ave ranks against every home in each area.
MeasureThis homeAlamo 94507Contra Costa County
Estimated valuepricier than$4,198,41495% of homesalmost all homes
Price per ft²pricier than$5363% of homes64% of homes
Living areabigger than7,833 ft²almost all homesalmost all homes
Lot sizebigger than1.44 ac94% of homes98% of homes
Year builtnewer than1930almost no homes3% of homes

About 512 Hemme Ave

How much is 512 Hemme Ave, Alamo, CA worth?

The TopHap Estimate for 512 Hemme Ave, Alamo, CA is $4,198,414 as of Oct 21, 2026. The likely range is $3,533,632 to $4,863,196. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 512 Hemme Ave, Alamo, CA last sell?

512 Hemme Ave, Alamo, CA last sold on Mar 24, 2020 for $2,250,000, according to the county's recorded deed. TopHap holds 2 recorded sales for this parcel.

How big is 512 Hemme Ave, Alamo, CA?

512 Hemme Ave, Alamo, CA has 10 bedrooms, 7 bathrooms and 7,833 square feet of living space.

When was 512 Hemme Ave, Alamo, CA built?

512 Hemme Ave, Alamo, CA was built in 1930, making it 96 years old. The building has 2 stories.

What schools serve 512 Hemme Ave, Alamo, CA?

512 Hemme Ave, Alamo, CA is assigned to Rancho Romero Elementary School (elementary), rated A+; Stone Valley Middle School (middle), rated A; San Ramon High School (high), rated A. All sit in San Ramon Valley Unified School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 512 Hemme Ave, Alamo, CA compare to other homes in Alamo 94507?

Among the 5,469 homes in Alamo 94507, it is worth more than 95% of them ($4,198,414 against a typical $2,436,554), its price per square foot is higher than 3% of them ($536 against a typical $780), it is bigger than almost all of them (7,833 ft² against a typical 3,113 ft²), its lot is bigger than 94% of them (1.44 ac against a typical 0.5 ac) and it is newer than almost none of them (1930 against a typical 1977). Measured against all of Contra Costa County, it is worth more than almost all 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 512 Hemme Ave, Alamo, CA?

The 2025 property tax bill for 512 Hemme Ave, Alamo, CA was $27,952. The county assessed it at $2,509,913.

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