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Single Family ResidenceResidential
$685,527$500 / 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 96How 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 $170,000 on Oct 30, 1996

21 ROTTKAMP ST

VALLEY STREAM, NY 11580
2
Baths
1,370 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.
4,000 ft²
Lot SizeThe size of the land the home sits on, from county records.
1941
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
7
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.
1
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$686K
$658K low$713K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$170,000 · Oct 30, 1996

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$11,739 (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.$454 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$196
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$258
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$454
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$454,000

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.Cape Cod
CountyNASSAU
Lot (acres)The size of the land the home sits on, from county records.0.09
ConstructionThe main material the home's frame and walls are built from.Frame (Unspecified)
HeatingThe type of heating system in the home.Central
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, Detached
PoolWhether the property has a pool, and what kind, such as in-ground.No
FeaturesExtra features found in county records. Records are not complete everywhere, so a missing feature does not always mean the home lacks it.Patio · 432 ft²

Transaction History(3)

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(1)

Neighborhood · ZIP 11580These 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.63
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.111
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.94

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.26%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.3.6%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.0%
PopulationHow many people live in this area.43,040
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.11,017 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$129,895
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$156,272
Average tempThe average temperature here across a full year.54°F
Annual precipHow much rain and melted snow falls here in a typical year.49 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.56%

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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

21 Rottkamp St 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 80% of homes in Nassau County
  • Smaller than 74% of homes in Nassau County
  • Has a smaller lot than 98% of homes in North Valley Stream
  • Older than 85% of homes in North Valley Stream

What homes are worth in Valley Stream 11580

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

This home
$502K$1.1M

This home is worth more than 29% of homes in Valley Stream 11580.

How it measures up in Valley Stream 11580

The dot is this home. The mark in the middle is the typical home in Valley Stream 11580.

Estimated value$685,527
CheaperTypical $736,879Pricier

Pricier than 29% of homes nearby

Price per ft²$500
CheaperTypical $519Pricier

Pricier than 41% of homes nearby

Living area1,370 ft²
SmallerTypical 1,404 ft²Bigger

Bigger than 45% of homes nearby

Lot size4,000 ft²
SmallerTypical 0.12 acBigger

Bigger than 5% of homes nearby

Year built1941
OlderTypical 1949Newer

Newer than 29% of homes nearby

How 21 Rottkamp St ranks against every home in each area.
MeasureThis homeNorth Valley StreamValley Stream 11580Nassau County
Estimated valuepricier than$685,52726% of homes29% of homes20% of homes
Price per ft²pricier than$50038% of homes41% of homes43% of homes
Living areabigger than1,370 ft²53% of homes45% of homes26% of homes
Lot sizebigger than4,000 ft²2% of homes5% of homes4% of homes
Year builtnewer than194115% of homes29% of homes25% of homes

About 21 Rottkamp St

How much is 21 Rottkamp St, Valley Stream, NY worth?

The TopHap Estimate for 21 Rottkamp St, Valley Stream, NY is $685,527 as of Oct 21, 2026. The likely range is $657,783 to $713,271. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Rottkamp St, Valley Stream, NY last sell?

21 Rottkamp St, Valley Stream, NY last sold on Oct 30, 1996 for $170,000, according to the county's recorded deed.

How big is 21 Rottkamp St, Valley Stream, NY?

21 Rottkamp St, Valley Stream, NY has 2 bathrooms, 1,370 square feet of living space and a 0.09-acre lot.

When was 21 Rottkamp St, Valley Stream, NY built?

21 Rottkamp St, Valley Stream, NY was built in 1941, making it 85 years old. It is a cape cod home. The building has 1 story.

How does 21 Rottkamp St, Valley Stream, NY compare to other homes in Valley Stream 11580?

Among the 10,974 homes in Valley Stream 11580, it is worth more than 29% of them ($685,527 against a typical $736,879), its price per square foot is higher than 41% of them ($500 against a typical $519), it is bigger than 45% of them (1,370 ft² against a typical 1,404 ft²), its lot is bigger than 5% of them (4,000 ft² against a typical 0.12 ac) and it is newer than 29% of them (1941 against a typical 1949). Measured against all of Nassau County, it is worth more than 20% 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 21 Rottkamp St, Valley Stream, NY?

The 2025 property tax bill for 21 Rottkamp St, Valley Stream, NY was $11,739. The county assessed it at $454.

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