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Single Family ResidenceResidential
$1,993,418$579 / 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 59How 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

21 ROUND HILL RD

ARMONK, NY 10504
3
Beds
2
Baths
3,443 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.
1 ac
Lot SizeThe size of the land the home sits on, from county records.
2000
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.

Valuation

$2M
$1.2M low$2.8M high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$18,151 (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.$22,000 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$2,200
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$19,800
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$22,000
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$1,358,024

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.45
1
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
23
WildfireProjected wildfire risk, scored 0 to 100, based on how much land burns in a typical year. Higher is riskier.
64
HeatProjected heat risk, scored 0 to 100, based on how many extremely hot days a year are expected. Higher is riskier.
95
StormProjected risk from heavy rainstorms, scored 0 to 100, based on how often extreme rainfall is expected. Higher is riskier.
43
DroughtProjected water shortage risk, scored 0 to 100. Higher means more strain on the local water supply.
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.Split Level
CountyWESTCHESTER
Lot (acres)The size of the land the home sits on, from county records.1.00
HeatingThe type of heating system in the home.Hot Water
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, Basement
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
Coman Hill Elementary School
Elementary · Grades KG–2 · 1.3 mi
H
Byram Hills High SchoolA+
High · Grades 9–12 · 1.8 mi
M
H. C. Crittenden Middle SchoolA-
Middle · Grades 6–8 · 2.8 mi

District: Byram Hills Central School District

Neighborhood · ZIP 10504These 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.1
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.114
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.103

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.39%
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.1.1%
PopulationHow many people live in this area.8,155
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.454 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$226,553
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$315,450
Average tempThe average temperature here across a full year.51°F
Annual precipHow much rain and melted snow falls here in a typical year.51 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.55%

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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 Round Hill Rd 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 89% of homes in Westchester County
  • Costs more per square foot than 67% of homes in Westchester County
  • Bigger than 85% of homes in Westchester County
  • Has a bigger lot than 87% of homes in Westchester County
  • Newer than 94% of homes in Westchester County

What homes are worth in Armonk 10504

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

This home
$608K$5M

This home is worth more than 50% of homes in Armonk 10504.

How it measures up in Armonk 10504

The dot is this home. The mark in the middle is the typical home in Armonk 10504.

Estimated value$1,993,418
CheaperTypical $1,987,662Pricier

Pricier than 50% of homes nearby

Price per ft²$579
CheaperTypical $638Pricier

Pricier than 34% of homes nearby

Living area3,443 ft²
SmallerTypical 3,134 ft²Bigger

Bigger than 58% of homes nearby

Lot size1 ac
SmallerTypical 1.53 acBigger

Bigger than 30% of homes nearby

Year built2000
OlderTypical 1972Newer

Newer than 81% of homes nearby

How 21 Round Hill Rd ranks against every home in each area.
MeasureThis homeArmonk 10504Westchester County
Estimated valuepricier than$1,993,41850% of homes89% of homes
Price per ft²pricier than$57934% of homes67% of homes
Living areabigger than3,443 ft²58% of homes85% of homes
Lot sizebigger than1 ac30% of homes87% of homes
Year builtnewer than200081% of homes94% of homes

About 21 Round Hill Rd

How much is 21 Round Hill Rd, Armonk, NY worth?

The TopHap Estimate for 21 Round Hill Rd, Armonk, NY is $1,993,418 as of Aug 30, 2026. The likely range is $1,173,709 to $2,813,127. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Round Hill Rd, Armonk, NY last sell?

21 Round Hill Rd, Armonk, NY last sold on Jan 1, 1900, according to the county's recorded deed.

How big is 21 Round Hill Rd, Armonk, NY?

21 Round Hill Rd, Armonk, NY has 3 bedrooms, 2 bathrooms, 3,443 square feet of living space and a 1.00-acre lot.

When was 21 Round Hill Rd, Armonk, NY built?

21 Round Hill Rd, Armonk, NY was built in 2000, making it 26 years old. It is a split level home. The building has 2 stories.

What schools serve 21 Round Hill Rd, Armonk, NY?

21 Round Hill Rd, Armonk, NY is assigned to Coman Hill Elementary School (elementary); Byram Hills High School (high), rated A+; H. C. Crittenden Middle School (middle), rated A-. All sit in Byram Hills Central School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 Round Hill Rd, Armonk, NY compare to other homes in Armonk 10504?

Among the 2,694 homes in Armonk 10504, it is worth more than 50% of them ($1,993,418 against a typical $1,987,662), its price per square foot is higher than 34% of them ($579 against a typical $638), it is bigger than 58% of them (3,443 ft² against a typical 3,134 ft²), its lot is bigger than 30% of them (1 ac against a typical 1.53 ac) and it is newer than 81% of them (2000 against a typical 1972). Measured against all of Westchester County, it is worth more than 89% 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 Round Hill Rd, Armonk, NY?

The 2025 property tax bill for 21 Round Hill Rd, Armonk, NY was $18,151. The county assessed it at $22,000.

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