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Single Family ResidenceResidential
$2,319,265$1,434 / 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 Jul 14, 2026

20 PROSPECT ST

CHARLESTOWN, MA 02129
3
Beds
3.5
Baths
1,617 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.
3,305 ft²
Lot SizeThe size of the land the home sits on, from county records.
1970
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

$2.3M
$2.2M low$2.4M high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$21,982 (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.$1,898,300 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$695,300
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$1,203,000
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$1,690,905

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.Colonial
CountySUFFOLK
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.2021
Lot (acres)The size of the land the home sits on, from county records.0.08
RoofThe main material covering the roof, such as asphalt shingle or tile.Asphalt
HeatingThe type of heating system in the home.Hot Water
CoolingThe type of cooling or air conditioning in the home.Yes
FireplaceWhether the home has a fireplace, and what kind.Yes
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(15)

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
Harvard / Kent Elementary SchoolC-
Elementary · Grades PK–5 · 0.1 mi
H
Charlestown High SchoolD+
High · Grades 9–12 · 0.4 mi
M
Warren / Prescott K-8 SchoolA-
Middle · Grades PK–8 · 0.4 mi

District: Boston School District

Neighborhood · ZIP 02129These 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.89
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.101
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.73

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.35%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.8.3%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.3%
PopulationHow many people live in this area.18,397
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.10,594 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$152,177
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$178,903
Average tempThe average temperature here across a full year.50°F
Annual precipHow much rain and melted snow falls here in a typical year.46 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

20 Prospect 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 more than 95% of homes in Suffolk County
  • Among the highest price per square foot in Charlestown 02129
  • Bigger than 70% of homes in Charlestown 02129
  • Has a bigger lot than 95% of homes in Charlestown 02129
  • Newer than 77% of homes in Suffolk County

What homes are worth in Charlestown 02129

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

This home
$467K$3.1M

This home is worth more than 93% of homes in Charlestown 02129.

How it measures up in Charlestown 02129

The dot is this home. The mark in the middle is the typical home in Charlestown 02129.

Estimated value$2,319,265
CheaperTypical $1,099,135Pricier

Pricier than 93% of homes nearby

Price per ft²$1434
CheaperTypical $945Pricier

Pricier than almost all homes nearby

Living area1,617 ft²
SmallerTypical 1,192 ft²Bigger

Bigger than 70% of homes nearby

Lot size3,305 ft²
SmallerTypical 1,089 ft²Bigger

Bigger than 95% of homes nearby

Year built1970
OlderTypical 1899Newer

Newer than 73% of homes nearby

How 20 Prospect St ranks against every home in each area.
MeasureThis homeCharlestown 02129Suffolk County
Estimated valuepricier than$2,319,26593% of homes95% of homes
Price per ft²pricier than$1434almost all homes94% of homes
Living areabigger than1,617 ft²70% of homes55% of homes
Lot sizebigger than3,305 ft²95% of homes57% of homes
Year builtnewer than197073% of homes77% of homes

About 20 Prospect St

How much is 20 Prospect St, Charlestown, MA worth?

The TopHap Estimate for 20 Prospect St, Charlestown, MA is $2,319,265 as of Jul 14, 2026. The likely range is $2,205,607 to $2,432,923. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 20 Prospect St, Charlestown, MA last sell?

20 Prospect St, Charlestown, MA last sold on Aug 3, 2007, according to the county's recorded deed. TopHap holds 5 recorded sales for this parcel.

How big is 20 Prospect St, Charlestown, MA?

20 Prospect St, Charlestown, MA has 3 bedrooms, 3.5 bathrooms, 1,617 square feet of living space and a 0.08-acre lot.

When was 20 Prospect St, Charlestown, MA built?

20 Prospect St, Charlestown, MA was built in 1970, making it 56 years old. It is a colonial home. The building has 2 stories.

What schools serve 20 Prospect St, Charlestown, MA?

20 Prospect St, Charlestown, MA is assigned to Harvard / Kent Elementary School (elementary), rated C-; Charlestown High School (high), rated D+; Warren / Prescott K-8 School (middle), rated A-. All sit in Boston School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 20 Prospect St, Charlestown, MA compare to other homes in Charlestown 02129?

Among the 5,259 homes in Charlestown 02129, it is worth more than 93% of them ($2,319,265 against a typical $1,099,135), its price per square foot is higher than almost all of them ($1434 against a typical $945), it is bigger than 70% of them (1,617 ft² against a typical 1,192 ft²), its lot is bigger than 95% of them (3,305 ft² against a typical 1,089 ft²) and it is newer than 73% of them (1970 against a typical 1899). Measured against all of Suffolk County, it is worth more than 95% 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 20 Prospect St, Charlestown, MA?

The 2025 property tax bill for 20 Prospect St, Charlestown, MA was $21,982. The county assessed it at $1,898,300.

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