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CondominiumResidential

421 Main St

CHARLESTOWN, MA 02129
885 ft²
Lot SizeThe size of the land the home sits on, from county records.
1899
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
Built 18993 units885–1,661 ft²
$2.7M
All units combinedThe sum of our current value estimates for every unit in the building — roughly what the whole building's homes are worth together.
$870K
Median unit valueThe middle unit value in this building by our estimate: half the units are worth more, half less.
$937
Median $/ft²The middle price per square foot across the building's units, by our current estimates. Useful for comparing units of different sizes.

+14.2%vs the Charlestown ZIP median sale $/ft² ($821)

Sales Performance

—
Median sale (12 mo)The middle sale price among this building's units that sold in the last 12 months, from recorded deeds.
—
1-yr changeHow the building's median sale price over the last 12 months compares with the 12 months before that.
0
Sales (12 mo)Units in this building that sold in the last 12 months, from recorded arms-length deeds.
0.0%
Turnover (12 mo)The share of units that changed hands in the last 12 months. Around 4–6% a year is typical; much higher can signal investor churn or a wave of exits.
This building's own appreciationThe building's own appreciation: for every unit that sold twice (held over a year), we compute its yearly price change between the two sales and take the middle value. This is the cleanest read on how this specific building performs, because it compares each unit to itself.
+2.9%per yeartypical hold 4.5 yrsfrom 7 same-unit resales
Median sale price (yearly, all time)Every recorded arms-length sale in the building since records begin, grouped by year: the bars count sales and the line tracks the median price paid.MedianSales
20032005200620102012202120232025
Sale price per ft² (yearly, all time)The middle price per square foot across the building's units, by our current estimates. Useful for comparing units of different sizes.$/ft²
20032005200620102012202120232025

10 arms-length sales on record for this building.

Unit Mix & Floor PlansThe building's recurring floor plans, found by grouping units with identical beds, baths and square footage in county records. Larger groups are the building's standard layouts; leftover units have one-off sizes.

2 bed
3 units

Value DistributionHow the building's units spread across value ranges by our current estimates. A wide spread usually means big differences in size, floor or view.

$830K–$830K
1 unit
$870K–$870K
1 unit
$1M–$1M
1 unit

Ownership & Financing

Owner-occupiedThe share of units where the owner lives in the unit, per county records. The rest are second homes or rentals.100%
Company-ownedUnits owned through an LLC, trust, or other company — a rough proxy for investor ownership.0%
Typical owner tenureThe middle number of years since each unit last changed hands — how long the current owners have been in place.3.6 yrs
Cash purchases (5 yrs)The share of purchases in the last 5 years with no mortgage recorded. High cash share is common in second-home and investor buildings.0%
Avg. loan-to-valueAverage current loan balance against unit value across the building. Low numbers mean owners hold lots of equity — a sign of financial stability.72%
Median owner equityThe middle dollar amount of equity (value minus loans) unit owners hold in this building.$861,938
Median tax billThe middle annual property tax bill among the building's units.$8,861
Pre-foreclosure noticesUnits with an active pre-foreclosure or foreclosure notice on file.0

Recent SalesThe latest recorded arms-length sales in the building, newest first.

Unit 3Jun 18, 2025$844,000Unit 1Mar 21, 2023$867,500Unit 3Nov 15, 2021$700,000Unit 3Jun 22, 2012$411,000Unit 2Feb 16, 2010$395,500Unit 3May 26, 2006$435,000Unit 2Aug 16, 2005$430,000Unit 2Oct 20, 2003$390,000Unit 3Jun 19, 2003$400,000Unit 1May 30, 2003$500,000

Values are TopHap estimates, not appraisals. Sales, ownership and tax figures come from recorded county documents via ATTOM and can lag by several weeks.

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.48 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.26%
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.Condominium
CountySUFFOLK
Lot (acres)The size of the land the home sits on, from county records.0.02
HeatingThe type of heating system in the home.Hot Water
FireplaceWhether the home has a fireplace, and what kind.Yes
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.

M
Clarence R. Edwards Middle School
Middle · Grades 6–8 · 0.2 mi
E
Horace Mann School For The Deaf
Elementary · Grades PK–12 · 0.2 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%

All UnitsEvery property record the county has at this street address, such as the units in a condo building. Prices shown are our estimates, not asking prices.

421 Main St
2 bd · 2.5 ba · 1,661 ft²
$1M
421 Main St
2 bd · 1.5 ba · 885 ft²
$830K
421 Main St # 3
2 bd · 1.5 ba · 900 ft²
$870K

Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.

About 421 Main St

How many units are in 421 Main St, Charlestown, MA?

421 Main St, Charlestown, MA has 3 residential units across built in 1899, according to county assessor records.

What is a unit at 421 Main St, Charlestown, MA worth?

The median TopHap Estimate across the 3 units at 421 Main St, Charlestown, MA is $870,045. That works out to $937 per square foot. Units run from 885 to 1,661 square feet. Estimates are modelled from recorded sales and assessments, not appraisals.

Is 421 Main St, Charlestown, MA expensive for Charlestown?

Units at 421 Main St, Charlestown, MA carry a median of $937 per square foot, 14% above the Charlestown median of $821 per square foot.

How often do units sell at 421 Main St, Charlestown, MA?

0 units at 421 Main St, Charlestown, MA sold in the last 12 months, out of 10 recorded arms-length sales all time. That is a turnover rate of 0.0% of the building per year.

Have units at 421 Main St, Charlestown, MA appreciated?

Across 7 repeat sales of the same unit, 421 Main St, Charlestown, MA returned a median 2.9% per year. Because each pair is the same unit bought and sold, the figure is not distorted by which units traded. The median owner held for 4.5 years.

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Assigned schools

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