Skip to content
Skip to content
TopHapOpen in map
Single Family ResidenceResidential
$995,598$252 / 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 94How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Jul 14, 2026
Last sold for $639,450 on Jan 6, 2014

21 RIVER ST

SAYVILLE, NY 11782
0
Baths
3,944 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.
0.39 ac
Lot SizeThe size of the land the home sits on, from county records.
1925
Year BuiltThe year the home was originally built, according to county records.

Valuation

$996K
$937K low$1.1M high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$639,450 · Jan 6, 2014
Est. Owner EquityRoughly how much of the home's value the owner would keep after paying off known loans. It is our estimate minus the loans still owed.$995,598
Est. Lendable EquityThe part of the owner's equity a lender would typically let them borrow against — about 80% of their equity.$796,478

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$15,928 (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.$56,500 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$15,400
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$41,100
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$795,774

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.79 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.78%
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.0.2 percent flood zone

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
CountySUFFOLK
Lot (acres)The size of the land the home sits on, from county records.0.39
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

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.

H
Sayville High SchoolA
High · Grades 9–12 · 1.0 mi
E
Lincoln Avenue Elementary SchoolA-
Elementary · Grades PK–5 · 1.6 mi
M
Sayville Middle SchoolB
Middle · Grades 6–8 · 2.1 mi

District: Sayville Union Free School District

Neighborhood · ZIP 11782These 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.81
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.108
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.61

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.31%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.3.8%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.1%
PopulationHow many people live in this area.16,111
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.3,152 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$137,080
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$164,768
Average tempThe average temperature here across a full year.52°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%

Ownership

OccupancyWhether the owner appears to live here or somewhere else. It is inferred from the mailing address on record.Owner occupied
Company ownedWhether the owner is a company or trust rather than a person.No

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 River 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 more than 87% of homes in Sayville 11782
  • Among the lowest price per square foot in Sayville 11782
  • Among the largest homes in Sayville 11782
  • Has a bigger lot than 79% of homes in Sayville 11782
  • Older than 97% of homes in Suffolk County

What homes are worth in Sayville 11782

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

This home
$508K$1.6M

This home is worth more than 87% of homes in Sayville 11782.

How it measures up in Sayville 11782

The dot is this home. The mark in the middle is the typical home in Sayville 11782.

Estimated value$995,598
CheaperTypical $738,455Pricier

Pricier than 87% of homes nearby

Price per ft²$252
CheaperTypical $470Pricier

Cheaper than almost all homes nearby

Living area3,944 ft²
SmallerTypical 1,525 ft²Bigger

Bigger than almost all homes nearby

Lot size0.39 ac
SmallerTypical 0.25 acBigger

Bigger than 79% of homes nearby

Year built1925
OlderTypical 1964Newer

Newer than 8% of homes nearby

How 21 River St ranks against every home in each area.
MeasureThis homeSayville 11782Suffolk County
Estimated valuepricier than$995,59887% of homes80% of homes
Price per ft²pricier than$252almost no homes3% of homes
Living areabigger than3,944 ft²almost all homes97% of homes
Lot sizebigger than0.39 ac79% of homes65% of homes
Year builtnewer than19258% of homes3% of homes

About 21 River St

How much is 21 River St, Sayville, NY worth?

The TopHap Estimate for 21 River St, Sayville, NY is $995,598 as of Jul 14, 2026. The likely range is $936,926 to $1,054,270. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 River St, Sayville, NY last sell?

21 River St, Sayville, NY last sold on Jan 6, 2014 for $639,450, according to the county's recorded deed. TopHap holds 2 recorded sales for this parcel.

How big is 21 River St, Sayville, NY?

21 River St, Sayville, NY has 3,944 square feet of living space and a 0.39-acre lot.

When was 21 River St, Sayville, NY built?

21 River St, Sayville, NY was built in 1925, making it 101 years old.

What schools serve 21 River St, Sayville, NY?

21 River St, Sayville, NY is assigned to Sayville High School (high), rated A; Lincoln Avenue Elementary School (elementary), rated A-; Sayville Middle School (middle), rated B. All sit in Sayville Union Free School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 River St, Sayville, NY compare to other homes in Sayville 11782?

Among the 5,681 homes in Sayville 11782, it is worth more than 87% of them ($995,598 against a typical $738,455), its price per square foot is higher than almost none of them ($252 against a typical $470), it is bigger than almost all of them (3,944 ft² against a typical 1,525 ft²), its lot is bigger than 79% of them (0.39 ac against a typical 0.25 ac) and it is newer than 8% of them (1925 against a typical 1964). Measured against all of Suffolk County, it is worth more than 80% 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 River St, Sayville, NY?

The 2024 property tax bill for 21 River St, Sayville, NY was $15,928. The county assessed it at $56,500.

Closest homes

More homes in Sayville 11782

Assigned schools

Explore the area

See this home in context

Open 21 River St on TopHap’s interactive map to compare it against every sale nearby, overlay school zones and flood risk, and run a CMA.

Open in map
A flyover of TopHap's photorealistic 3D map, with recorded sale prices pinned to homes
Search any address, city, zip, or county…3D$1.9M$6.25MOpen in map