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Single Family ResidenceResidential
$425,074$290 / 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 94How 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

100 UNION ST

MARLBOROUGH, MA 01752
3
Beds
1.5
Baths
1,468 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.
0.77 ac
Lot SizeThe size of the land the home sits on, from county records.
1938
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.

Valuation

$425K
$399K low$451K high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$4,406 (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.$446,900 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$222,100
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$224,800
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$511,955

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.0.77
RoofThe main material covering the roof, such as asphalt shingle or tile.Asphalt
HeatingThe type of heating system in the home.Steam
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(7)

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
1LT Charles W. Whitcomb SchoolD
Middle · Grades 6–8 · 0.3 mi
E
Goodnow Brothers Elementary SchoolD+
Elementary · Grades KG–5 · 0.6 mi
H
Marlborough High SchoolD+
High · Grades 9–12 · 0.7 mi

District: Marlborough School District

Neighborhood · ZIP 01752These 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.100
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 100.65

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.26%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.9.1%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.2%
PopulationHow many people live in this area.42,223
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.1,953 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$88,959
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$112,206
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.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

100 Union 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 less than 91% of homes in Middlesex County
  • Costs less per square foot than 92% of homes in Middlesex County
  • Smaller than 67% of homes in Middlesex County
  • Has a bigger lot than 73% of homes in Middlesex County
  • Older than 78% of homes in Marlborough 01752

What homes are worth in Marlborough 01752

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

This home
$197K$1M

This home is worth more than 24% of homes in Marlborough 01752.

How it measures up in Marlborough 01752

The dot is this home. The mark in the middle is the typical home in Marlborough 01752.

Estimated value$425,074
CheaperTypical $527,945Pricier

Pricier than 24% of homes nearby

Price per ft²$290
CheaperTypical $336Pricier

Pricier than 21% of homes nearby

Living area1,468 ft²
SmallerTypical 1,591 ft²Bigger

Bigger than 43% of homes nearby

Lot size0.77 ac
SmallerTypical 0.46 acBigger

Bigger than 68% of homes nearby

Year built1938
OlderTypical 1967Newer

Newer than 22% of homes nearby

How 100 Union St ranks against every home in each area.
MeasureThis homeMarlborough 01752Middlesex County
Estimated valuepricier than$425,07424% of homes9% of homes
Price per ft²pricier than$29021% of homes8% of homes
Living areabigger than1,468 ft²43% of homes33% of homes
Lot sizebigger than0.77 ac68% of homes73% of homes
Year builtnewer than193822% of homes35% of homes

About 100 Union St

How much is 100 Union St, Marlborough, MA worth?

The TopHap Estimate for 100 Union St, Marlborough, MA is $425,074 as of Sep 24, 2026. The likely range is $398,675 to $451,473. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 100 Union St, Marlborough, MA last sell?

100 Union St, Marlborough, MA last sold on May 22, 2025, according to the county's recorded deed. TopHap holds 2 recorded sales for this parcel.

How big is 100 Union St, Marlborough, MA?

100 Union St, Marlborough, MA has 3 bedrooms, 1.5 bathrooms, 1,468 square feet of living space and a 0.77-acre lot.

When was 100 Union St, Marlborough, MA built?

100 Union St, Marlborough, MA was built in 1938, making it 88 years old. It is a cape cod home. The building has 2 stories.

What schools serve 100 Union St, Marlborough, MA?

100 Union St, Marlborough, MA is assigned to 1LT Charles W. Whitcomb School (middle), rated D; Goodnow Brothers Elementary School (elementary), rated D+; Marlborough High School (high), rated D+. All sit in Marlborough School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 100 Union St, Marlborough, MA compare to other homes in Marlborough 01752?

Among the 10,751 homes in Marlborough 01752, it is worth more than 24% of them ($425,074 against a typical $527,945), its price per square foot is higher than 21% of them ($290 against a typical $336), it is bigger than 43% of them (1,468 ft² against a typical 1,591 ft²), its lot is bigger than 68% of them (0.77 ac against a typical 0.46 ac) and it is newer than 22% of them (1938 against a typical 1967). Measured against all of Middlesex County, it is worth more than 9% 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 100 Union St, Marlborough, MA?

The 2025 property tax bill for 100 Union St, Marlborough, MA was $4,406. The county assessed it at $446,900.

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