Duplex (2 Units, Any Combination)Residential
Last sold for $58,536 on Apr 23, 1998
21 DECATUR ST
COS COB, CT 06807
4
Beds
3 / 2
Baths
2,128 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.
0.1 ac
Lot SizeThe size of the land the home sits on, from county records.
1989
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.
Valuation
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$58,536 · Apr 23, 1998
Tax & Assessment
Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$7,213 (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.$583,590 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$411,040
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$172,550
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$408,513
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.47
23
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
13
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.
96
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.
Projected Flood DepthHow deep a serious flood is expected to get here at some point in the next 30 years. Shown in inches.3 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.30%
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.Duplex (2 Units, Any Combination)
StyleThe architectural style of the home, such as ranch or colonial.Duplex Single
CountyWESTERN CONNECTICUT
Lot (acres)The size of the land the home sits on, from county records.0.10
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
PoolWhether the property has a pool, and what kind, such as in-ground.No
FeaturesExtra features found in county records. Records are not complete everywhere, so a missing feature does not always mean the home lacks it.Deck
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.
EMH
Cos Cob SchoolB
Elementary · Grades KG–5 · 0.5 mi
Central Middle SchoolA-
Middle · Grades 6–8 · 0.7 mi
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%
Owner Tools
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How this home compares
21 Decatur 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.
- Has a smaller lot than 98% of homes in Cos Cob 06807
- Newer than 84% 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.
Living area2,128 ft²
SmallerTypical 2,388 ft²Bigger
Bigger than 41% of homes nearby
Lot size0.1 ac
SmallerTypical 0.29 acBigger
Bigger than 2% of homes nearby
Year built1989
OlderTypical 1964Newer
Newer than 84% of homes nearby
| Measure | This home | Cos Cob 06807 | Western Connecticut County |
|---|---|---|---|
| Living areabigger than | 2,128 ft² | 41% of homes | 54% of homes |
| Lot sizebigger than | 0.1 ac | 2% of homes | 2% of homes |
| Year builtnewer than | 1989 | 84% of homes | 80% of homes |
About 21 Decatur St
When did 21 Decatur St, Cos Cob, CT last sell?
21 Decatur St, Cos Cob, CT last sold on Apr 23, 1998 for $58,536, according to the county's recorded deed. TopHap holds 2 recorded sales for this parcel.
How big is 21 Decatur St, Cos Cob, CT?
21 Decatur St, Cos Cob, CT has 4 bedrooms, 3 bathrooms, 2,128 square feet of living space and a 0.10-acre lot.
When was 21 Decatur St, Cos Cob, CT built?
21 Decatur St, Cos Cob, CT was built in 1989, making it 37 years old. It is a duplex single home. The building has 2 stories.
What schools serve 21 Decatur St, Cos Cob, CT?
21 Decatur 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 Decatur St, Cos Cob, CT compare to other homes in Cos Cob 06807?
Among the 2,396 homes in Cos Cob 06807, it is bigger than 41% of them (2,128 ft² against a typical 2,388 ft²), its lot is bigger than 2% of them (0.1 ac against a typical 0.29 ac) and it is newer than 84% of them (1989 against a typical 1964). 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 Decatur St, Cos Cob, CT?
The 2024 property tax bill for 21 Decatur St, Cos Cob, CT was $7,213. The county assessed it at $583,590.
More homes on Decatur St
- 24 Decatur St # 2$859K2 bd · 2.5 ba · 1,643 ft² · Sold $850K · Jul 2026
- 36 Decatur St0.36 ac · Sold $1.3M · May 2019
- 24 Decatur St # 3$951K3 bd · 2.5 ba · 1,835 ft² · Sold $585K · Jun 2012
- 40 Decatur St$1.6M3 bd · 3 ba · 1,896 ft² · Sold $400K · Nov 2011
- 25 Decatur St8 bd · 7 ba · 4,801 ft² · Sold Jun 2010
- 17 Decatur St$1.3M0.19 ac · Sold $500K · Jun 2002
- 19 Decatur St5 bd · 3.5 ba · 2,487 ft² · Sold $417K · Jan 2002
- 24 Decatur St # 1$884K2 bd · 2.5 ba · 1,631 ft² · Sold $280K · Sep 2000
- 1 Decatur St6 bd · 2 ba · 2,052 ft² · Sold $275K · Jun 1993
- 32 Decatur St6 bd · 3 ba · 2,940 ft² · Sold Jan 1900
- 22 Decatur St$1.2M2 bd · 1 ba · 1,291 ft² · Sold Jan 1900
- 34 Decatur St6 bd · 3 ba · 2,940 ft² · Sold Jan 1900
Closest homes
- 19 Decatur St63 ft · 5 bd · 3.5 ba · 2,487 ft² · Sold $417K · Jan 2002
- 25 Cedar St65 ft · 8 bd · 7 ba · 4,801 ft² · Sold $800K · May 2005
- 13 Rippowam Rd96 ft · 6 bd · 3 ba · 3,457 ft² · Sold $725K · Mar 2003
- 17 Decatur St$1.3M132 ft · 0.19 ac · Sold $500K · Jun 2002
- 34 Decatur St140 ft · 6 bd · 3 ba · 2,940 ft² · Sold Jan 1900
- 15 Rippowam Rd$1.5M164 ft · 3 bd · 2 ba · 1,868 ft² · Sold $75K · Aug 2001
- 32 Decatur St140 ft · 6 bd · 3 ba · 2,940 ft² · Sold Jan 1900
- 40 Decatur St$1.6M206 ft · 3 bd · 3 ba · 1,896 ft² · Sold $400K · Nov 2011
More homes in Cos Cob 06807
- 33 Mead Ave$2.7M4 bd · 4.5 ba · 3,492 ft² · Sold $2.7M · Aug 2026
- 51 Dandy Dr$3.3M4 bd · 3 ba · 3,543 ft² · Sold $3.3M · Aug 2026
- 9 Deluca Dr$2.4M4 bd · 3 ba · 2,620 ft² · Sold $2.4M · Aug 2026
- 4 Cos Cob Ave$1.5M4 bd · 3 ba · 2,720 ft² · Sold $1.5M · Aug 2026
- 86 Dandy Dr$1.9M4 bd · 3.5 ba · 3,546 ft² · Sold $1.9M · Aug 2026
- 12 Old Post Rd$2M4 bd · 2.5 ba · 3,034 ft² · Sold $2M · Aug 2026
- 15 River Rd$918K2 bd · 2 ba · 1,270 ft² · Sold $914K · Aug 2026
- 9 Walnut St0.52 ac · Sold $1.4M · Aug 2026
- 106 Orchard St$2.5M5 bd · 4.5 ba · 2,939 ft² · Sold $2.5M · Jul 2026
- 681 River Rd$2.5M4 bd · 4.5 ba · 3,826 ft² · Sold $2.4M · Jul 2026
- 500 River Rd$1.2M2 bd · 2 ba · 1,830 ft² · Sold $1.2M · Jul 2026
- 14 Pond Pl$3M3 bd · 2.5 ba · 2,082 ft² · Sold $3M · Jul 2026
Assigned schools
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