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Single Family ResidenceResidential
$478,822$264 / 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 Aug 30, 2026
Last sold for $210,000 on Dec 13, 2001

21 RIVERBY ST

LOWELL, MA 01850
3
Beds
2
Baths
1,811 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.
0.25 ac
Lot SizeThe size of the land the home sits on, from county records.
1988
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.
7
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.

Valuation

$479K
$449K low$508K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$210,000 · Dec 13, 2001

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$5,858 (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.$510,300 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$161,900
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$348,400
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$494,190

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.17 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.30%
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.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.0.25
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
PoolWhether the property has a pool, and what kind, such as in-ground.No
FeaturesExtra features found in county records. Records are not complete everywhere, so a missing feature does not always mean the home lacks it.Deck

Transaction History(9)

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
GreenhalgeC-
Elementary · Grades PK–4 · 0.4 mi
M
Henry J Robinson Middle SchoolC-
Middle · Grades 5–8 · 0.7 mi
H
Lowell High SchoolC-
High · Grades 9–12 · 0.8 mi

District: Lowell School District

Neighborhood · ZIP 01850These 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.109
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 100.82

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.96%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.11%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.18%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.1%
PopulationHow many people live in this area.16,865
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.11,591 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$64,769
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$72,358
Average tempThe average temperature here across a full year.48°F
Annual precipHow much rain and melted snow falls here in a typical year.45 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 Riverby 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 87% of homes in Middlesex County
  • Costs less per square foot than 95% of homes in Middlesex County
  • Has a bigger lot than 76% of homes in Lowell 01850
  • Newer than 93% of homes in Lowell 01850

What homes are worth in Lowell 01850

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

This home
$200K$593K

This home is worth more than 83% of homes in Lowell 01850.

How it measures up in Lowell 01850

The dot is this home. The mark in the middle is the typical home in Lowell 01850.

Estimated value$478,822
CheaperTypical $406,113Pricier

Pricier than 83% of homes nearby

Price per ft²$264
CheaperTypical $293Pricier

Pricier than 26% of homes nearby

Living area1,811 ft²
SmallerTypical 1,561 ft²Bigger

Bigger than 61% of homes nearby

Lot size0.25 ac
SmallerTypical 0.14 acBigger

Bigger than 76% of homes nearby

Year built1988
OlderTypical 1925Newer

Newer than 93% of homes nearby

How 21 Riverby St ranks against every home in each area.
MeasureThis homeLowell 01850Middlesex County
Estimated valuepricier than$478,82283% of homes13% of homes
Price per ft²pricier than$26426% of homes5% of homes
Living areabigger than1,811 ft²61% of homes50% of homes
Lot sizebigger than0.25 ac76% of homes43% of homes
Year builtnewer than198893% of homes81% of homes

About 21 Riverby St

How much is 21 Riverby St, Lowell, MA worth?

The TopHap Estimate for 21 Riverby St, Lowell, MA is $478,822 as of Aug 30, 2026. The likely range is $449,445 to $508,199. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Riverby St, Lowell, MA last sell?

21 Riverby St, Lowell, MA last sold on Dec 13, 2001 for $210,000, according to the county's recorded deed. TopHap holds 3 recorded sales for this parcel.

How big is 21 Riverby St, Lowell, MA?

21 Riverby St, Lowell, MA has 3 bedrooms, 2 bathrooms, 1,811 square feet of living space and a 0.25-acre lot.

When was 21 Riverby St, Lowell, MA built?

21 Riverby St, Lowell, MA was built in 1988, making it 38 years old. It is a cape cod home. The building has 2 stories.

What schools serve 21 Riverby St, Lowell, MA?

21 Riverby St, Lowell, MA is assigned to Greenhalge (elementary), rated C-; Henry J Robinson Middle School (middle), rated C-; Lowell High School (high), rated C-. All sit in Lowell School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 Riverby St, Lowell, MA compare to other homes in Lowell 01850?

Among the 3,731 homes in Lowell 01850, it is worth more than 83% of them ($478,822 against a typical $406,113), its price per square foot is higher than 26% of them ($264 against a typical $293), it is bigger than 61% of them (1,811 ft² against a typical 1,561 ft²), its lot is bigger than 76% of them (0.25 ac against a typical 0.14 ac) and it is newer than 93% of them (1988 against a typical 1925). Measured against all of Middlesex County, it is worth more than 13% 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 Riverby St, Lowell, MA?

The 2025 property tax bill for 21 Riverby St, Lowell, MA was $5,858. The county assessed it at $510,300.

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