Skip to content
Skip to content
TopHapOpen in map
CondominiumResidential
Last sold for $265,000 on Dec 13, 2024

21 SOUTH ST

WESTBOROUGH, MA 01581
1900
Year BuiltThe year the home was originally built, according to county records.
3
StoriesHow many floors the home has above ground.
Built 190019 units441–1,045 ft²
$4.4M
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.
$262K
Median unit valueThe middle unit value in this building by our estimate: half the units are worth more, half less.
$450
Median $/ft²The middle price per square foot across the building's units, by our current estimates. Useful for comparing units of different sizes.

+9.5%vs the Westborough ZIP median sale $/ft² ($411)

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.
+2.0%per yeartypical hold 5.1 yrsfrom 26 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
20042007201120152017202020222025
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
20042007201120152017202020222025

47 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.

Every unit: size vs estimated valueEvery unit in the building as one dot: across is its size, up is our current value estimate, and color is its bedroom count. Vertical columns of dots are recurring floor plans; the height spread within a column shows how much floor, view and condition move prices for the same layout.
$206K$270K$334K$399K441 ft²562 ft²683 ft²803 ft²924 ft²1,045 ft²
1 bd
1 bed
19 units
Recurring 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.
1 bd · 1 ba · 579 ft²
2 units
1 bd · 1 ba · 596 ft²
2 units
1 bd · 1 ba · 598 ft²
2 units
1 bd · 1 ba · 612 ft²
2 units
One-off layouts
11 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.

$206K–$214K
2 units
$237K–$250K
3 units
$255K–$276K
6 units
$285K–$294K
2 units
$309K–$309K
1 unit
$348K–$348K
1 unit
$399K–$399K
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.53%
Company-ownedUnits owned through an LLC, trust, or other company — a rough proxy for investor ownership.16%
Typical owner tenureThe middle number of years since each unit last changed hands — how long the current owners have been in place.8.0 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.83%
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.39%
Median owner equityThe middle dollar amount of equity (value minus loans) unit owners hold in this building.$274,016
Median tax billThe middle annual property tax bill among the building's units.$3,825
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 34May 21, 2025$265,000Unit 35May 20, 2025$270,000BuildingDec 13, 2024$265,000Unit 32Jun 20, 2023$253,500Unit 22Dec 13, 2022$235,000Unit 25Dec 12, 2022$260,000Unit 32Apr 6, 2021$195,000Unit 27Mar 8, 2021$130,000Unit 26Mar 1, 2021$167,000Unit 34Sep 1, 2020$160,000

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

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$4,144 (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.$254,400 (2025)
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$254,400
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$251,750

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Condominium
StyleThe architectural style of the home, such as ranch or colonial.Condo/Apartment
CountyWORCESTER
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.Roll Tar & Gravel
HeatingThe type of heating system in the home.Forced Air With Air Conditioning
CoolingThe type of cooling or air conditioning in the home.Yes
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(3)

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.

H
Westborough High SchoolA
High · Grades 9–12 · 0.4 mi
E
J. Harding Armstrong Elementary SchoolA-
Elementary · Grades KG–3 · 0.5 mi
M
Sarah W. Gibbons Middle SchoolA
Middle · Grades 7–8 · 0.6 mi

District: Westborough School District

Neighborhood · ZIP 01581These 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.65
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.99
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.59

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.96%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.33%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.5.3%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.5%
PopulationHow many people live in this area.21,880
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.1,023 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$137,510
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$171,995
Average tempThe average temperature here across a full year.48°F
Annual precipHow much rain and melted snow falls here in a typical year.48 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.50%

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.

21 South St
1 bd · 1 ba · 602 ft²
$252K
21 South St # 20
1 bd · 1 ba · 525 ft²
$237K
21 South St # 22
1 bd · 1 ba · 579 ft²
$285K
21 South St # 23
1 bd · 1 ba · 598 ft²
$258K
21 South St # 24
1 bd · 1 ba · 612 ft²
$275K
21 South St # 25
1 bd · 1 ba · 596 ft²
21 South St # 26
1 bd · 1 ba · 522 ft²
21 South St # 27
1 bd · 1 ba · 443 ft²
$206K
21 South St # 28
1 bd · 1 ba · 662 ft²
$309K
21 South St # 29
1 bd · 1 ba · 868 ft²
$348K
21 South St # 30
1 bd · 1 ba · 516 ft²
21 South St # 31
1 bd · 1 ba · 602 ft²
$250K
21 South St # 32
1 bd · 1 ba · 579 ft²
$263K
21 South St # 33
1 bd · 1 ba · 598 ft²
$276K
21 South St # 34
1 bd · 1 ba · 612 ft²
$255K
21 South St # 35
1 bd · 1 ba · 596 ft²
$260K
21 South St # 36
1 bd · 1 ba · 512 ft²
$245K
21 South St # 37
1 bd · 1 ba · 441 ft²
$214K
21 South St # 38
1 bd · 1 ba · 673 ft²
$294K
21 South St # 39
1 bd · 1 ba · 1,045 ft²
$399K

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

About 21 South St

How many units are in 21 South St, Westborough, MA?

21 South St, Westborough, MA has 19 residential units across built in 1900, according to county assessor records.

What is a unit at 21 South St, Westborough, MA worth?

The median TopHap Estimate across the 19 units at 21 South St, Westborough, MA is $261,525. That works out to $450 per square foot. Units run from 441 to 1,045 square feet. Estimates are modelled from recorded sales and assessments, not appraisals.

Is 21 South St, Westborough, MA expensive for Westborough?

Units at 21 South St, Westborough, MA carry a median of $450 per square foot, 10% above the Westborough median of $411 per square foot.

How often do units sell at 21 South St, Westborough, MA?

0 units at 21 South St, Westborough, MA sold in the last 12 months, out of 47 recorded arms-length sales all time. That is a turnover rate of 0.0% of the building per year.

Have units at 21 South St, Westborough, MA appreciated?

Across 26 repeat sales of the same unit, 21 South St, Westborough, MA returned a median 2.0% 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 5.1 years.

What floor plans does 21 South St, Westborough, MA have?

The most common plan at 21 South St, Westborough, MA is a 1-bedroom of 579 square feet, repeated 2 times, with a median estimate of $274,153. TopHap identifies 4 recurring plans in the building.

More homes on South St

Closest homes

More homes in Westborough 01581

Assigned schools

Explore the area

See this home in context

Open 21 South St on TopHap’s interactive map to compare it against every sale nearby, overlay school zones and flood risk, and run a CMA.

Open in map
A flyover of TopHap's photorealistic 3D map, with recorded sale prices pinned to homes
Search any address, city, zip, or county…3D$1.9M$6.25MOpen in map