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Single Family ResidenceResidential
$687,327$378 / 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 97How 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
Last sold for $309,900 on May 29, 2015

21 SOUTH ST

BILLERICA, MA 01821
2
Beds
2
Baths
1,817 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.
1980
Year BuiltThe year the home was originally built, according to county records.
2
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

$687K
$668K low$706K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$309,900 · May 29, 2015

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$6,385 (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.$561,600 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$263,000
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$298,600
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$604,865

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
CountyMIDDLESEX
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.Forced Air With Air Conditioning
CoolingThe type of cooling or air conditioning in the home.Yes
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

Transaction History(8)

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.

M
Locke Middle SchoolB+
Middle · Grades 5–7 · 1.4 mi
H
Billerica Memorial High SchoolC
High · Grades 8–12 · 1.6 mi

District: Billerica School District

Neighborhood · ZIP 01821These 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.40
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.100
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.82

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.98%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.28%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.3.8%
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.31,495
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.1,857 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$133,460
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$152,991
Average tempThe average temperature here across a full year.49°F
Annual precipHow much rain and melted snow falls here in a typical year.47 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

21 South 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.

  • Costs less per square foot than 73% of homes in Middlesex County
  • Has a smaller lot than 89% of homes in Billerica 01821
  • Newer than 72% of homes in Middlesex County

What homes are worth in Billerica 01821

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

This home
$286K$1.1M

This home is worth more than 55% of homes in Billerica 01821.

How it measures up in Billerica 01821

The dot is this home. The mark in the middle is the typical home in Billerica 01821.

Estimated value$687,327
CheaperTypical $672,655Pricier

Pricier than 55% of homes nearby

Price per ft²$378
CheaperTypical $368Pricier

Pricier than 56% of homes nearby

Living area1,817 ft²
SmallerTypical 1,872 ft²Bigger

Bigger than 46% of homes nearby

Lot size0.17 ac
SmallerTypical 0.57 acBigger

Bigger than 11% of homes nearby

Year built1980
OlderTypical 1970Newer

Newer than 69% of homes nearby

How 21 South St ranks against every home in each area.
MeasureThis homeBillerica 01821Middlesex County
Estimated valuepricier than$687,32755% of homes36% of homes
Price per ft²pricier than$37856% of homes27% of homes
Living areabigger than1,817 ft²46% of homes50% of homes
Lot sizebigger than0.17 ac11% of homes30% of homes
Year builtnewer than198069% of homes72% of homes

About 21 South St

How much is 21 South St, Billerica, MA worth?

The TopHap Estimate for 21 South St, Billerica, MA is $687,327 as of Jul 14, 2026. The likely range is $668,204 to $706,450. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 South St, Billerica, MA last sell?

21 South St, Billerica, MA last sold on May 29, 2015 for $309,900, according to the county's recorded deed. TopHap holds 3 recorded sales for this parcel.

How big is 21 South St, Billerica, MA?

21 South St, Billerica, MA has 2 bedrooms, 2 bathrooms, 1,817 square feet of living space and a 0.17-acre lot.

When was 21 South St, Billerica, MA built?

21 South St, Billerica, MA was built in 1980, making it 46 years old. It is a cape cod home. The building has 2 stories.

What schools serve 21 South St, Billerica, MA?

21 South St, Billerica, MA is assigned to Locke Middle School (middle), rated B+; Billerica Memorial High School (high), rated C. All sit in Billerica School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 South St, Billerica, MA compare to other homes in Billerica 01821?

Among the 10,003 homes in Billerica 01821, it is worth more than 55% of them ($687,327 against a typical $672,655), its price per square foot is higher than 56% of them ($378 against a typical $368), it is bigger than 46% of them (1,817 ft² against a typical 1,872 ft²), its lot is bigger than 11% of them (0.17 ac against a typical 0.57 ac) and it is newer than 69% of them (1980 against a typical 1970). Measured against all of Middlesex County, it is worth more than 36% 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 South St, Billerica, MA?

The 2025 property tax bill for 21 South St, Billerica, MA was $6,385. The county assessed it at $561,600.

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