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Single Family ResidenceResidential
$684,105$441 / 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 Sep 24, 2026
Last sold for $405,000 on Nov 15, 2017

21 DONCASTER AVE

WEST ISLIP, NY 11795
0
Baths
1,550 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.
1959
Year BuiltThe year the home was originally built, according to county records.

Valuation

$684K
$660K low$709K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$405,000 · Nov 15, 2017

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$12,010 (2024)
Assessed ValueThe value the county assigns to this home to calculate property tax. It is often lower than what the home would sell for.$40,600 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$8,400
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$32,200
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$571,831

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountySUFFOLK
Lot (acres)The size of the land the home sits on, from county records.0.25
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(1)

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
Manetuck Elementary SchoolC-
Elementary · Grades KG–5 · 0.3 mi
M
Udall Road Middle SchoolA-
Middle · Grades 6–8 · 0.5 mi
H
West Islip High SchoolA-
High · Grades 9–12 · 1.9 mi

District: West Islip Union Free School District

Neighborhood · ZIP 11795These 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.37
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.104
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.72

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.2.7%
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.25,576
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.3,944 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$160,580
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$181,705
Average tempThe average temperature here across a full year.53°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.58%

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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 Doncaster 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.

  • Smaller than 71% of homes in West Islip 11795
  • Older than 71% of homes in Suffolk County

What homes are worth in West Islip 11795

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

This home
$509K$1.8M

This home is worth more than 42% of homes in West Islip 11795.

How it measures up in West Islip 11795

The dot is this home. The mark in the middle is the typical home in West Islip 11795.

Estimated value$684,105
CheaperTypical $703,740Pricier

Pricier than 42% of homes nearby

Price per ft²$441
CheaperTypical $435Pricier

Pricier than 52% of homes nearby

Living area1,550 ft²
SmallerTypical 1,840 ft²Bigger

Bigger than 29% of homes nearby

Lot size0.25 ac
SmallerTypical 0.25 acBigger

Bigger than 60% of homes nearby

Year built1959
OlderTypical 1957Newer

Newer than 58% of homes nearby

How 21 Doncaster Ave ranks against every home in each area.
MeasureThis homeWest Islip 11795Suffolk County
Estimated valuepricier than$684,10542% of homes48% of homes
Price per ft²pricier than$44152% of homes59% of homes
Living areabigger than1,550 ft²29% of homes43% of homes
Lot sizebigger than0.25 ac60% of homes46% of homes
Year builtnewer than195958% of homes29% of homes

About 21 Doncaster Ave

How much is 21 Doncaster Ave, West Islip, NY worth?

The TopHap Estimate for 21 Doncaster Ave, West Islip, NY is $684,105 as of Sep 24, 2026. The likely range is $659,667 to $708,543. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Doncaster Ave, West Islip, NY last sell?

21 Doncaster Ave, West Islip, NY last sold on Nov 15, 2017 for $405,000, according to the county's recorded deed.

How big is 21 Doncaster Ave, West Islip, NY?

21 Doncaster Ave, West Islip, NY has 1,550 square feet of living space and a 0.25-acre lot.

When was 21 Doncaster Ave, West Islip, NY built?

21 Doncaster Ave, West Islip, NY was built in 1959, making it 67 years old.

What schools serve 21 Doncaster Ave, West Islip, NY?

21 Doncaster Ave, West Islip, NY is assigned to Manetuck Elementary School (elementary), rated C-; Udall Road Middle School (middle), rated A-; West Islip High School (high), rated A-. All sit in West Islip Union Free School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 Doncaster Ave, West Islip, NY compare to other homes in West Islip 11795?

Among the 8,125 homes in West Islip 11795, it is worth more than 42% of them ($684,105 against a typical $703,740), its price per square foot is higher than 52% of them ($441 against a typical $435), it is bigger than 29% of them (1,550 ft² against a typical 1,840 ft²), its lot is bigger than 60% of them (0.25 ac against a typical 0.25 ac) and it is newer than 58% of them (1959 against a typical 1957). Measured against all of Suffolk County, it is worth more than 48% 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 Doncaster Ave, West Islip, NY?

The 2024 property tax bill for 21 Doncaster Ave, West Islip, NY was $12,010. The county assessed it at $40,600.

More homes on Doncaster Ave

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Assigned schools

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