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CondominiumResidential
$1,231,042$510 / 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 88How 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 $645,000 on Feb 3, 2010

21 CHRISTIANO ST

COS COB, CT 06807
Building report
3
Beds
3.5
Baths
2,412 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.
2004
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.
8
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

$1.2M
$1.1M low$1.4M high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$645,000 · Feb 3, 2010

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$7,776 (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.$629,160 (2025)
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$629,160
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$629,160
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$440,412

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Condominium
StyleThe architectural style of the home, such as ranch or colonial.Condo/Apartment
CountyWESTERN CONNECTICUT
ConstructionThe main material the home's frame and walls are built from.Frame (Unspecified)
RoofThe main material covering the roof, such as asphalt shingle or tile.Asphalt
HeatingThe type of heating system in the home.Forced Air With Air Conditioning
CoolingThe type of cooling or air conditioning in the home.Yes
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
Cos Cob SchoolB
Elementary · Grades KG–5 · 0.5 mi
M
Central Middle SchoolA-
Middle · Grades 6–8 · 0.6 mi
H
Greenwich High SchoolA+
High · Grades 9–12 · 1.1 mi

District: Greenwich School District

Neighborhood · ZIP 06807These 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.54
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.112
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.94%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.34%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.6.3%
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.7,630
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.2,321 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$180,144
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$235,340
Average tempThe average temperature here across a full year.52°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.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 Christiano 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 83% of homes in Cos Cob 06807
  • Costs less per square foot than 94% of homes in Cos Cob 06807
  • Newer than 91% of homes in Western Connecticut County

What homes are worth in Cos Cob 06807

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

This home
$674K$4.4M

This home is worth more than 17% of homes in Cos Cob 06807.

How it measures up in Cos Cob 06807

The dot is this home. The mark in the middle is the typical home in Cos Cob 06807.

Estimated value$1,231,042
CheaperTypical $1,757,850Pricier

Pricier than 17% of homes nearby

Price per ft²$510
CheaperTypical $751Pricier

Pricier than 6% of homes nearby

Living area2,412 ft²
SmallerTypical 2,388 ft²Bigger

Bigger than 51% of homes nearby

Year built2004
OlderTypical 1964Newer

Newer than 90% of homes nearby

How 21 Christiano St ranks against every home in each area.
MeasureThis homeCos Cob 06807Western Connecticut County
Estimated valuepricier than$1,231,04217% of homes70% of homes
Price per ft²pricier than$5106% of homes67% of homes
Living areabigger than2,412 ft²51% of homes63% of homes
Year builtnewer than200490% of homes91% of homes

About 21 Christiano St

How much is 21 Christiano St, Cos Cob, CT worth?

The TopHap Estimate for 21 Christiano St, Cos Cob, CT is $1,231,042 as of Sep 24, 2026. The likely range is $1,077,756 to $1,384,328. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Christiano St, Cos Cob, CT last sell?

21 Christiano St, Cos Cob, CT last sold on Feb 3, 2010 for $645,000, according to the county's recorded deed.

How big is 21 Christiano St, Cos Cob, CT?

21 Christiano St, Cos Cob, CT has 3 bedrooms, 3.5 bathrooms and 2,412 square feet of living space.

When was 21 Christiano St, Cos Cob, CT built?

21 Christiano St, Cos Cob, CT was built in 2004, making it 22 years old. It is a condo/apartment home. The building has 2 stories.

What schools serve 21 Christiano St, Cos Cob, CT?

21 Christiano St, Cos Cob, CT is assigned to Cos Cob School (elementary), rated B; Central Middle School (middle), rated A-; Greenwich High School (high), rated A+. All sit in Greenwich School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 Christiano St, Cos Cob, CT compare to other homes in Cos Cob 06807?

Among the 2,396 homes in Cos Cob 06807, it is worth more than 17% of them ($1,231,042 against a typical $1,757,850), its price per square foot is higher than 6% of them ($510 against a typical $751), it is bigger than 51% of them (2,412 ft² against a typical 2,388 ft²) and it is newer than 90% of them (2004 against a typical 1964). Measured against all of Western Connecticut County, it is worth more than 70% 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 Christiano St, Cos Cob, CT?

The 2025 property tax bill for 21 Christiano St, Cos Cob, CT was $7,776. The county assessed it at $629,160.

More homes on Christiano St

Closest homes

More homes in Cos Cob 06807

Assigned schools

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