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Single Family ResidenceResidential
$755,532$561 / 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 93How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Aug 30, 2026
Last sold for $419,000 on Jul 20, 2005

21 ALDER ST

WALTHAM, MA 02453
1.5
Baths
1,346 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.
2,631 ft²
Lot SizeThe size of the land the home sits on, from county records.
1880
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.

Valuation

$756K
$705K low$806K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$419,000 · Jul 20, 2005

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$6,238 (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.$635,200 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$329,600
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$305,600
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$1,217,900

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
CountyMIDDLESEX
Lot (acres)The size of the land the home sits on, from county records.0.06
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.Steam
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(2)

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
Henry Whittemore Elementary SchoolB
Elementary · Grades KG–5 · 0.4 mi
M
John W. McDevitt Middle SchoolB
Middle · Grades 6–8 · 0.8 mi
H
Waltham Sr High SchoolC
High · Grades 9–12 · 1.9 mi

District: Waltham School District

Neighborhood · ZIP 02453These 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.106
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.104
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.31%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.6.8%
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.32,080
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.8,464 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$106,981
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$136,606
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 Alder 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 more per square foot than 74% of homes in Waltham 02453
  • Smaller than 75% of homes in Waltham 02453
  • Has a smaller lot than 98% of homes in Southside
  • Older than 95% of homes in Middlesex County

What homes are worth in Waltham 02453

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

This home
$349K$1.3M

This home is worth more than 45% of homes in Waltham 02453.

How it measures up in Waltham 02453

The dot is this home. The mark in the middle is the typical home in Waltham 02453.

Estimated value$755,532
CheaperTypical $779,900Pricier

Pricier than 45% of homes nearby

Price per ft²$561
CheaperTypical $492Pricier

Pricier than 74% of homes nearby

Living area1,346 ft²
SmallerTypical 1,867 ft²Bigger

Bigger than 25% of homes nearby

Lot size2,631 ft²
SmallerTypical 0.15 acBigger

Bigger than 2% of homes nearby

Year built1880
OlderTypical 1930Newer

Newer than 6% of homes nearby

How 21 Alder St ranks against every home in each area.
MeasureThis homeSouthsideWaltham 02453Middlesex County
Estimated valuepricier than$755,53259% of homes45% of homes47% of homes
Price per ft²pricier than$56167% of homes74% of homes71% of homes
Living areabigger than1,346 ft²29% of homes25% of homes27% of homes
Lot sizebigger than2,631 ft²2% of homes2% of homes3% of homes
Year builtnewer than18809% of homes6% of homes5% of homes

About 21 Alder St

How much is 21 Alder St, Waltham, MA worth?

The TopHap Estimate for 21 Alder St, Waltham, MA is $755,532 as of Aug 30, 2026. The likely range is $705,189 to $805,875. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Alder St, Waltham, MA last sell?

21 Alder St, Waltham, MA last sold on Jul 20, 2005 for $419,000, according to the county's recorded deed.

How big is 21 Alder St, Waltham, MA?

21 Alder St, Waltham, MA has 1.5 bathrooms, 1,346 square feet of living space and a 0.06-acre lot.

When was 21 Alder St, Waltham, MA built?

21 Alder St, Waltham, MA was built in 1880, making it 146 years old. It is a colonial home. The building has 2 stories.

What schools serve 21 Alder St, Waltham, MA?

21 Alder St, Waltham, MA is assigned to Henry Whittemore Elementary School (elementary), rated B; John W. McDevitt Middle School (middle), rated B; Waltham Sr High School (high), rated C. All sit in Waltham School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 Alder St, Waltham, MA compare to other homes in Waltham 02453?

Among the 6,296 homes in Waltham 02453, it is worth more than 45% of them ($755,532 against a typical $779,900), its price per square foot is higher than 74% of them ($561 against a typical $492), it is bigger than 25% of them (1,346 ft² against a typical 1,867 ft²), its lot is bigger than 2% of them (2,631 ft² against a typical 0.15 ac) and it is newer than 6% of them (1880 against a typical 1930). Measured against all of Middlesex County, it is worth more than 47% 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 Alder St, Waltham, MA?

The 2025 property tax bill for 21 Alder St, Waltham, MA was $6,238. The county assessed it at $635,200.

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