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Single Family ResidenceResidential
$1,161,577$506 / 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 Oct 21, 2026

20439 GERNSIDE DR

WALNUT, CA 91789
4
Beds
3
Baths
2,294 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.
0.25 ac
Lot SizeThe size of the land the home sits on, from county records.
1975
Year BuiltThe year the home was originally built, according to county records.

Valuation

$1.2M
$1.1M low$1.2M high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$7,367 (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.$566,698 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$198,902
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$367,796
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$555,587

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountyLOS ANGELES
Lot (acres)The size of the land the home sits on, from county records.0.25
ConstructionThe main material the home's frame and walls are built from.Wood (Unspecified)
HeatingThe type of heating system in the home.Central
CoolingThe type of cooling or air conditioning in the home.Central
PoolWhether the property has a pool, and what kind, such as in-ground.Yes

Transaction History(2)

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.

M
South Pointe Middle SchoolA+
Middle · Grades 6–8 · 0.5 mi
E
Walnut Elementary SchoolA+
Elementary · Grades KG–5 · 0.6 mi
H
Diamond Bar High SchoolA
High · Grades 9–12 · 1.4 mi

District: Walnut Valley Unified School District

Neighborhood · ZIP 91789These 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.33
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.103
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.413

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.36%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.6.8%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.6%
PopulationHow many people live in this area.45,013
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.2,690 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$110,530
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$137,487
Average tempThe average temperature here across a full year.64°F
Annual precipHow much rain and melted snow falls here in a typical year.18 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.73%

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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

20439 Gernside 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 more than 73% of homes in Los Angeles County
  • Costs less per square foot than 82% of homes in Walnut 91789
  • Bigger than 77% of homes in Los Angeles County
  • Has a bigger lot than 72% of homes in Los Angeles County
  • Older than 73% of homes in Walnut 91789

What homes are worth in Walnut 91789

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

This home
$503K$2.6M

This home is worth more than 56% of homes in Walnut 91789.

How it measures up in Walnut 91789

The dot is this home. The mark in the middle is the typical home in Walnut 91789.

Estimated value$1,161,577
CheaperTypical $1,103,521Pricier

Pricier than 56% of homes nearby

Price per ft²$506
CheaperTypical $563Pricier

Pricier than 18% of homes nearby

Living area2,294 ft²
SmallerTypical 1,984 ft²Bigger

Bigger than 66% of homes nearby

Lot size0.25 ac
SmallerTypical 0.23 acBigger

Bigger than 60% of homes nearby

Year built1975
OlderTypical 1983Newer

Newer than 27% of homes nearby

How 20439 Gernside Dr ranks against every home in each area.
MeasureThis homeWalnut 91789Los Angeles County
Estimated valuepricier than$1,161,57756% of homes73% of homes
Price per ft²pricier than$50618% of homes33% of homes
Living areabigger than2,294 ft²66% of homes77% of homes
Lot sizebigger than0.25 ac60% of homes72% of homes
Year builtnewer than197527% of homes71% of homes

About 20439 Gernside Dr

How much is 20439 Gernside Dr, Walnut, CA worth?

The TopHap Estimate for 20439 Gernside Dr, Walnut, CA is $1,161,577 as of Oct 21, 2026. The likely range is $1,103,231 to $1,219,923. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 20439 Gernside Dr, Walnut, CA last sell?

20439 Gernside Dr, Walnut, CA last sold on Jan 1, 1900, according to the county's recorded deed.

How big is 20439 Gernside Dr, Walnut, CA?

20439 Gernside Dr, Walnut, CA has 4 bedrooms, 3 bathrooms, 2,294 square feet of living space and a 0.25-acre lot.

When was 20439 Gernside Dr, Walnut, CA built?

20439 Gernside Dr, Walnut, CA was built in 1975, making it 51 years old.

What schools serve 20439 Gernside Dr, Walnut, CA?

20439 Gernside Dr, Walnut, CA is assigned to South Pointe Middle School (middle), rated A+; Walnut Elementary School (elementary), rated A+; Diamond Bar High School (high), rated A. All sit in Walnut Valley Unified School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 20439 Gernside Dr, Walnut, CA compare to other homes in Walnut 91789?

Among the 13,202 homes in Walnut 91789, it is worth more than 56% of them ($1,161,577 against a typical $1,103,521), its price per square foot is higher than 18% of them ($506 against a typical $563), it is bigger than 66% of them (2,294 ft² against a typical 1,984 ft²), its lot is bigger than 60% of them (0.25 ac against a typical 0.23 ac) and it is newer than 27% of them (1975 against a typical 1983). Measured against all of Los Angeles County, it is worth more than 73% 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 20439 Gernside Dr, Walnut, CA?

The 2025 property tax bill for 20439 Gernside Dr, Walnut, CA was $7,367. The county assessed it at $566,698.

More homes on Gernside Dr

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