Duplex (2 Units, Any Combination)Residential
20 TREMONT ST
COS COB, CT 06807
2
Beds
2
Baths
1,732 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.
0.17 ac
Lot SizeThe size of the land the home sits on, from county records.
1914
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.
7
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.
Tax & Assessment
Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$7,100 (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.$574,490 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$443,380
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$131,110
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$574,490
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$402,143
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
25
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
8
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.19 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.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.Duplex (2 Units, Any Combination)
StyleThe architectural style of the home, such as ranch or colonial.Duplex Single
CountyWESTERN CONNECTICUT
Effective Year BuiltAn adjusted build year that accounts for condition and major remodels. A big renovation can make a home count as newer than it is.1960
Lot (acres)The size of the land the home sits on, from county records.0.17
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.Hot Water
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
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 · 0.2 mi
Central Middle SchoolA-
Middle · Grades 6–8 · 0.6 mi
Greenwich High SchoolA+
High · Grades 9–12 · 0.7 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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Claim this homeData 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
20 Tremont 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.
- Smaller than 76% of homes in Cos Cob 06807
- Has a smaller lot than 89% of homes in Western Connecticut County
- Older than 93% of homes in Western Connecticut County
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 area1,732 ft²
SmallerTypical 2,388 ft²Bigger
Bigger than 24% of homes nearby
Lot size0.17 ac
SmallerTypical 0.29 acBigger
Bigger than 15% of homes nearby
Year built1914
OlderTypical 1964Newer
Newer than 8% of homes nearby
| Measure | This home | Cos Cob 06807 | Western Connecticut County |
|---|---|---|---|
| Living areabigger than | 1,732 ft² | 24% of homes | 41% of homes |
| Lot sizebigger than | 0.17 ac | 15% of homes | 11% of homes |
| Year builtnewer than | 1914 | 8% of homes | 7% of homes |
About 20 Tremont St
When did 20 Tremont St, Cos Cob, CT last sell?
20 Tremont St, Cos Cob, CT last sold on Jan 1, 1900, according to the county's recorded deed.
How big is 20 Tremont St, Cos Cob, CT?
20 Tremont St, Cos Cob, CT has 2 bedrooms, 2 bathrooms, 1,732 square feet of living space and a 0.17-acre lot.
When was 20 Tremont St, Cos Cob, CT built?
20 Tremont St, Cos Cob, CT was built in 1914, making it 112 years old. It is a duplex single home. The building has 2 stories.
What schools serve 20 Tremont St, Cos Cob, CT?
20 Tremont 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 20 Tremont 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 24% of them (1,732 ft² against a typical 2,388 ft²), its lot is bigger than 15% of them (0.17 ac against a typical 0.29 ac) and it is newer than 8% of them (1914 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 20 Tremont St, Cos Cob, CT?
The 2025 property tax bill for 20 Tremont St, Cos Cob, CT was $7,100. The county assessed it at $574,490.
More homes on Tremont St
- 7 Tremont St$2.3M3 bd · 3.5 ba · 2,744 ft² · Sold $1.8M · Apr 2024
- 8 Tremont St$1.9M4 bd · 3 ba · 1,986 ft² · Sold $1.6M · Nov 2023
- 24 Tremont St$1.5M4 bd · 3 ba · 1,938 ft² · Sold $900K · Dec 2022
- 19 Tremont St$1.2M3 bd · 1.5 ba · 1,177 ft² · Sold $765K · Sep 2021
- 10 Tremont St3 bd · 2 ba · 1,344 ft² · Sold $575K · Oct 2019
- 25 Tremont St$1.4M3 bd · 2.5 ba · 1,924 ft² · Sold $770K · Oct 2014
- 14 Tremont St5 bd · 5.5 ba · 3,626 ft² · Sold $775K · Oct 2004
- 6 Tremont St$1.5M4 bd · 2 ba · 1,518 ft² · Sold $720K · Sep 2003
- 17 Tremont St$1.5M2 bd · 3 ba · 1,444 ft² · Sold $415K · Jul 1997
- 18 Tremont St$1.2M1 bd · 2 ba · 866 ft² · Sold $62K · Jun 1996
- 9 Tremont St$1.6M3 bd · 2.5 ba · 1,832 ft² · Sold $308K · Sep 1995
- 22 Tremont St$3.5M5 bd · 4 ba · 3,820 ft² · Sold Jan 1900
Closest homes
- 18 Tremont St$1.2M35 ft · 1 bd · 2 ba · 866 ft² · Sold $62K · Jun 1996
- 22 Tremont St$3.5M55 ft · 5 bd · 4 ba · 3,820 ft² · Sold Jan 1900
- 26 Tremont St72 ft · 3 bd · 1 ba · 1,200 ft² · Sold Jan 1900
- 16 Tremont St$1.3M91 ft · 3 bd · 1 ba · 1,072 ft² · Sold Jan 1900
- 16 Schubert Ln$1.1M113 ft · 2 bd · 1 ba · 795 ft² · Sold Jan 1900
- 14 Schubert Ln$1.7M134 ft · 3 bd · 2.5 ba · 1,648 ft² · Sold $735K · May 2005
- 18 Schubert Ln$2M154 ft · 4 bd · 2.5 ba · 2,096 ft² · Sold $1.1M · Jul 2013
- 24 Tremont St$1.5M127 ft · 4 bd · 3 ba · 1,938 ft² · Sold $900K · Dec 2022
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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