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Single Family ResidenceResidential
$474,156$555 / 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 90How 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 $300,000 on Jan 18, 2006

21 SYLVAN AVE

RIVERHEAD, NY 11901
3
Beds
1
Baths
855 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.
0.24 ac
Lot SizeThe size of the land the home sits on, from county records.
1997
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.

Valuation

$474K
$426K low$522K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$300,000 · Jan 18, 2006

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$3,841 (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.$225,500 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$122,200
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$103,300
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$357,936

Climate Risk

Projected Flood DepthHow deep a serious flood is expected to get here at some point in the next 30 years. Shown in inches.12 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.45%
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.Mobile Home
CountySUFFOLK
Lot (acres)The size of the land the home sits on, from county records.0.24
FoundationWhat the home is built on, such as a concrete slab, a crawl space, or a basement.No Foundation
HeatingThe type of heating system in the home.Yes
PoolWhether the property has a pool, and what kind, such as in-ground.No
ViewThe type of view from the property, or another feature of the site that affects value.Inferior

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.

Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.

E
Phillips Avenue SchoolD-
Elementary · Grades PK–4 · 2.3 mi
M
Riverhead Middle SchoolD
Middle · Grades 6–8 · 3.8 mi
H
Riverhead Senior High SchoolC-
High · Grades 9–12 · 3.9 mi

District: Riverhead Central School District

Neighborhood · ZIP 11901These 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.129
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.107
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.50

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.90%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.14%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.10%
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.29,638
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.531 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$77,609
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$107,711
Average tempThe average temperature here across a full year.52°F
Annual precipHow much rain and melted snow falls here in a typical year.47 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 Sylvan 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.

  • Worth less than 93% of homes in Suffolk County
  • Costs more per square foot than 90% of homes in Flanders
  • Smaller than 95% of homes in Suffolk County
  • Has a smaller lot than 67% of homes in Riverhead 11901
  • Newer than 84% of homes in Suffolk County

What homes are worth in Riverhead 11901

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

This home
$338K$1.8M

This home is worth more than 22% of homes in Riverhead 11901.

How it measures up in Riverhead 11901

The dot is this home. The mark in the middle is the typical home in Riverhead 11901.

Estimated value$474,156
CheaperTypical $606,742Pricier

Pricier than 22% of homes nearby

Price per ft²$555
CheaperTypical $405Pricier

Pricier than 87% of homes nearby

Living area855 ft²
SmallerTypical 1,374 ft²Bigger

Bigger than 16% of homes nearby

Lot size0.24 ac
SmallerTypical 0.31 acBigger

Bigger than 33% of homes nearby

Year built1997
OlderTypical 1991Newer

Newer than 68% of homes nearby

How 21 Sylvan Ave ranks against every home in each area.
MeasureThis homeFlandersRiverhead 11901Suffolk County
Estimated valuepricier than$474,15644% of homes22% of homes7% of homes
Price per ft²pricier than$55590% of homes87% of homes79% of homes
Living areabigger than855 ft²18% of homes16% of homes5% of homes
Lot sizebigger than0.24 ac40% of homes33% of homes39% of homes
Year builtnewer than199771% of homes68% of homes84% of homes

About 21 Sylvan Ave

How much is 21 Sylvan Ave, Riverhead, NY worth?

The TopHap Estimate for 21 Sylvan Ave, Riverhead, NY is $474,156 as of Sep 24, 2026. The likely range is $426,120 to $522,192. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Sylvan Ave, Riverhead, NY last sell?

21 Sylvan Ave, Riverhead, NY last sold on Jan 18, 2006 for $300,000, according to the county's recorded deed. TopHap holds 3 recorded sales for this parcel.

How big is 21 Sylvan Ave, Riverhead, NY?

21 Sylvan Ave, Riverhead, NY has 3 bedrooms, 1 bathrooms, 855 square feet of living space and a 0.24-acre lot.

When was 21 Sylvan Ave, Riverhead, NY built?

21 Sylvan Ave, Riverhead, NY was built in 1997, making it 29 years old. It is a mobile home home. The building has 1 story.

What schools serve 21 Sylvan Ave, Riverhead, NY?

21 Sylvan Ave, Riverhead, NY is assigned to Phillips Avenue School (elementary), rated D-; Riverhead Middle School (middle), rated D; Riverhead Senior High School (high), rated C-. All sit in Riverhead Central School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 Sylvan Ave, Riverhead, NY compare to other homes in Riverhead 11901?

Among the 9,720 homes in Riverhead 11901, it is worth more than 22% of them ($474,156 against a typical $606,742), its price per square foot is higher than 87% of them ($555 against a typical $405), it is bigger than 16% of them (855 ft² against a typical 1,374 ft²), its lot is bigger than 33% of them (0.24 ac against a typical 0.31 ac) and it is newer than 68% of them (1997 against a typical 1991). Measured against all of Suffolk County, it is worth more than 7% 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 Sylvan Ave, Riverhead, NY?

The 2024 property tax bill for 21 Sylvan Ave, Riverhead, NY was $3,841. The county assessed it at $225,500.

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