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Single Family ResidenceResidential
$765,737$570 / 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 97How 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 $522,000 on Jul 20, 2016

509 LASSEN CT

ROHNERT PARK, CA 94928
4
Beds
2
Baths
1,344 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.
0.3 ac
Lot SizeThe size of the land the home sits on, from county records.
1973
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
4
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

$766K
$744K low$787K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$522,000 · Jul 20, 2016

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$6,984 (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.$617,934 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$247,409
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$370,525
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$605,818

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.31
51
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
79
WildfireProjected wildfire risk, scored 0 to 100, based on how much land burns in a typical year. Higher is riskier.
27
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.15 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.30%
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.minimal

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
StyleThe architectural style of the home, such as ranch or colonial.Custom Design
CountySONOMA
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.1994
Lot (acres)The size of the land the home sits on, from county records.0.30
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.Composition Shingle
HeatingThe type of heating system in the home.None
CoolingThe type of cooling or air conditioning in the home.Yes
FireplaceWhether the home has a fireplace, and what kind.Yes
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(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.

H
Rancho Cortate High SchoolC-
High · Grades 9–12 · 1.4 mi
E
Thomas Page AcademyB-
Elementary · Grades KG–8 · 2.0 mi

District: Cotati-Rohnert Park Unified School District

Neighborhood · ZIP 94928These 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.74
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.87
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.429

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.20%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.9.1%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.4%
PopulationHow many people live in this area.38,270
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.5,396 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$93,170
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$115,834
Average tempThe average temperature here across a full year.58°F
Annual precipHow much rain and melted snow falls here in a typical year.33 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

509 Lassen Ct 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 90% of homes in Holiday Park
  • Costs more per square foot than 96% of homes in Rohnert Park 94928
  • Smaller than 65% of homes in Sonoma County
  • Has a bigger lot than 97% of homes in Holiday Park
  • Newer than 94% of homes in Holiday Park

What homes are worth in Rohnert Park 94928

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

This home
$329K$999K

This home is worth more than 67% of homes in Rohnert Park 94928.

How it measures up in Rohnert Park 94928

The dot is this home. The mark in the middle is the typical home in Rohnert Park 94928.

Estimated value$765,737
CheaperTypical $699,668Pricier

Pricier than 67% of homes nearby

Price per ft²$570
CheaperTypical $427Pricier

Pricier than 96% of homes nearby

Living area1,344 ft²
SmallerTypical 1,546 ft²Bigger

Bigger than 37% of homes nearby

Lot size0.3 ac
SmallerTypical 0.13 acBigger

Bigger than 94% of homes nearby

Year built1973
OlderTypical 1980Newer

Newer than 21% of homes nearby

How 509 Lassen Ct ranks against every home in each area.
MeasureThis homeHoliday ParkRohnert Park 94928Sonoma County
Estimated valuepricier than$765,73790% of homes67% of homes49% of homes
Price per ft²pricier than$57083% of homes96% of homes70% of homes
Living areabigger than1,344 ft²64% of homes37% of homes35% of homes
Lot sizebigger than0.3 ac97% of homes94% of homes71% of homes
Year builtnewer than197394% of homes21% of homes41% of homes

About 509 Lassen Ct

How much is 509 Lassen Ct, Rohnert Park, CA worth?

The TopHap Estimate for 509 Lassen Ct, Rohnert Park, CA is $765,737 as of Aug 30, 2026. The likely range is $744,378 to $787,096. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 509 Lassen Ct, Rohnert Park, CA last sell?

509 Lassen Ct, Rohnert Park, CA last sold on Jul 20, 2016 for $522,000, according to the county's recorded deed.

How big is 509 Lassen Ct, Rohnert Park, CA?

509 Lassen Ct, Rohnert Park, CA has 4 bedrooms, 2 bathrooms, 1,344 square feet of living space and a 0.30-acre lot.

When was 509 Lassen Ct, Rohnert Park, CA built?

509 Lassen Ct, Rohnert Park, CA was built in 1973, making it 53 years old. It is a custom design home. The building has 1 story.

What schools serve 509 Lassen Ct, Rohnert Park, CA?

509 Lassen Ct, Rohnert Park, CA is assigned to Rancho Cortate High School (high), rated C-; Thomas Page Academy (elementary), rated B-. All sit in Cotati-Rohnert Park Unified School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 509 Lassen Ct, Rohnert Park, CA compare to other homes in Rohnert Park 94928?

Among the 13,012 homes in Rohnert Park 94928, it is worth more than 67% of them ($765,737 against a typical $699,668), its price per square foot is higher than 96% of them ($570 against a typical $427), it is bigger than 37% of them (1,344 ft² against a typical 1,546 ft²), its lot is bigger than 94% of them (0.3 ac against a typical 0.13 ac) and it is newer than 21% of them (1973 against a typical 1980). Measured against all of Sonoma County, it is worth more than 49% 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 509 Lassen Ct, Rohnert Park, CA?

The 2025 property tax bill for 509 Lassen Ct, Rohnert Park, CA was $6,984. The county assessed it at $617,934.

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