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Single Family ResidenceResidential
$334,460$311 / 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 95How 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

21 KNOLL DR

GROTON, CT 06340
3
Beds
1
Baths
1,075 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.
0.27 ac
Lot SizeThe size of the land the home sits on, from county records.
1955
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
6
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

$334K
$316K low$353K high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$3,832 (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.$129,850 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$64,974
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$64,876
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$129,850
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$90,895

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.19 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.34%
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.1 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
StyleThe architectural style of the home, such as ranch or colonial.Cape Cod
CountySOUTHEASTERN CONNECTICUT
Lot (acres)The size of the land the home sits on, from county records.0.27
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
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
FeaturesExtra features found in county records. Records are not complete everywhere, so a missing feature does not always mean the home lacks it.Elevator

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
Thames River Magnet SchoolC+
Elementary · Grades PK–5 · 0.4 mi
M
Groton Middle SchoolC
Middle · Grades 6–8 · 3.0 mi
H
Robert E. Fitch High SchoolC+
High · Grades 9–12 · 3.2 mi

District: Groton School District

Neighborhood · ZIP 06340These 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.104
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.109
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.56

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.91%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.23%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.9.6%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.0.8%
PopulationHow many people live in this area.27,657
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.992 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$80,998
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$95,942
Average tempThe average temperature here across a full year.51°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.56%

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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 Knoll Dr 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 73% of homes in Southeastern Connecticut County
  • Costs more per square foot than 67% of homes in Southeastern Connecticut County
  • Smaller than 81% of homes in Southeastern Connecticut County
  • Has a smaller lot than 74% of homes in Southeastern Connecticut County
  • Older than 66% of homes in Southeastern Connecticut County

What homes are worth in Groton 06340

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

This home
$191K$2M

This home is worth more than 34% of homes in Groton 06340.

How it measures up in Groton 06340

The dot is this home. The mark in the middle is the typical home in Groton 06340.

Estimated value$334,460
CheaperTypical $385,579Pricier

Pricier than 34% of homes nearby

Price per ft²$311
CheaperTypical $289Pricier

Pricier than 62% of homes nearby

Living area1,075 ft²
SmallerTypical 1,425 ft²Bigger

Bigger than 25% of homes nearby

Lot size0.27 ac
SmallerTypical 0.28 acBigger

Bigger than 46% of homes nearby

Year built1955
OlderTypical 1960Newer

Newer than 43% of homes nearby

How 21 Knoll Dr ranks against every home in each area.
MeasureThis homeGroton 06340Southeastern Connecticut County
Estimated valuepricier than$334,46034% of homes27% of homes
Price per ft²pricier than$31162% of homes67% of homes
Living areabigger than1,075 ft²25% of homes19% of homes
Lot sizebigger than0.27 ac46% of homes26% of homes
Year builtnewer than195543% of homes34% of homes

About 21 Knoll Dr

How much is 21 Knoll Dr, Groton, CT worth?

The TopHap Estimate for 21 Knoll Dr, Groton, CT is $334,460 as of Sep 24, 2026. The likely range is $316,115 to $352,805. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Knoll Dr, Groton, CT last sell?

21 Knoll Dr, Groton, CT last sold on Jan 1, 1900, according to the county's recorded deed.

How big is 21 Knoll Dr, Groton, CT?

21 Knoll Dr, Groton, CT has 3 bedrooms, 1 bathrooms, 1,075 square feet of living space and a 0.27-acre lot.

When was 21 Knoll Dr, Groton, CT built?

21 Knoll Dr, Groton, CT was built in 1955, making it 71 years old. It is a cape cod home. The building has 1 story.

What schools serve 21 Knoll Dr, Groton, CT?

21 Knoll Dr, Groton, CT is assigned to Thames River Magnet School (elementary), rated C+; Groton Middle School (middle), rated C; Robert E. Fitch High School (high), rated C+. All sit in Groton School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 Knoll Dr, Groton, CT compare to other homes in Groton 06340?

Among the 7,236 homes in Groton 06340, it is worth more than 34% of them ($334,460 against a typical $385,579), its price per square foot is higher than 62% of them ($311 against a typical $289), it is bigger than 25% of them (1,075 ft² against a typical 1,425 ft²), its lot is bigger than 46% of them (0.27 ac against a typical 0.28 ac) and it is newer than 43% of them (1955 against a typical 1960). Measured against all of Southeastern Connecticut County, it is worth more than 27% 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 Knoll Dr, Groton, CT?

The 2025 property tax bill for 21 Knoll Dr, Groton, CT was $3,832. The county assessed it at $129,850.

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