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Single Family ResidenceResidential
$706,538$406 / 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 96How 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 $130,000 on Dec 4, 1990

21 RIVER ST

SOUTH YARMOUTH, MA 02664
3
Beds
2.5
Baths
1,740 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.
0.42 ac
Lot SizeThe size of the land the home sits on, from county records.
1780
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.

Valuation

$707K
$677K low$737K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$130,000 · Dec 4, 1990
Est. Owner EquityRoughly how much of the home's value the owner would keep after paying off known loans. It is our estimate minus the loans still owed.$406,538
Est. Lendable EquityThe part of the owner's equity a lender would typically let them borrow against — about 80% of their equity.$325,230
Loan-to-ValueHow much is still owed on the home compared to what it is worth. 80% means loans equal 80% of our estimate, so it shifts when the estimate does.48%
1st MortgageA loan still believed to be open on this home, in the order lenders get repaid. The first position is paid back before the second.$200,000
CITIZENS BANK · recorded Jul 5, 2007
2nd MortgageA loan still believed to be open on this home, in the order lenders get repaid. The first position is paid back before the second.$100,000
ROCKLAND TRUST CO

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$3,675 (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.$519,100 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$256,000
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$263,100
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$640,205

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.24 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.45%
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.0.2 percent flood zone

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
CountyBARNSTABLE
Lot (acres)The size of the land the home sits on, from county records.0.42
RoofThe main material covering the roof, such as asphalt shingle or tile.Asphalt
HeatingThe type of heating system in the home.Hot Water
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(10)

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
Dennis Yarmouth Regional High SchoolC
High · Grades 9–12 · 1.4 mi
E
Station Avenue Elementary SchoolB+
Elementary · Grades KG–3 · 1.5 mi
M
Mattacheese Middle SchoolB-
Middle · Grades 6–8 · 2.5 mi

District: Dennis-Yarmouth School District

Neighborhood · ZIP 02664These 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.94
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.96
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.44

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.66%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.22%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.8.9%
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.10,036
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.1,247 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$85,867
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$102,512
Average tempThe average temperature here across a full year.50°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%

Ownership

OccupancyWhether the owner appears to live here or somewhere else. It is inferred from the mailing address on record.Owner occupied
Company ownedWhether the owner is a company or trust rather than a person.Yes

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 River 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 95% of homes in South Yarmouth 02664
  • Bigger than 78% of homes in South Yarmouth 02664
  • Has a bigger lot than 80% of homes in South Yarmouth 02664
  • Among the oldest homes in South Yarmouth 02664

What homes are worth in South Yarmouth 02664

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

This home
$374K$2M

This home is worth more than 53% of homes in South Yarmouth 02664.

How it measures up in South Yarmouth 02664

The dot is this home. The mark in the middle is the typical home in South Yarmouth 02664.

Estimated value$706,538
CheaperTypical $697,094Pricier

Pricier than 53% of homes nearby

Price per ft²$406
CheaperTypical $562Pricier

Pricier than 5% of homes nearby

Living area1,740 ft²
SmallerTypical 1,296 ft²Bigger

Bigger than 78% of homes nearby

Lot size0.42 ac
SmallerTypical 0.29 acBigger

Bigger than 80% of homes nearby

Year built1780
OlderTypical 1968Newer

Older than almost all homes nearby

How 21 River St ranks against every home in each area.
MeasureThis homeSouth Yarmouth 02664Barnstable County
Estimated valuepricier than$706,53853% of homes43% of homes
Price per ft²pricier than$4065% of homes21% of homes
Living areabigger than1,740 ft²78% of homes59% of homes
Lot sizebigger than0.42 ac80% of homes48% of homes
Year builtnewer than1780almost no homesalmost no homes

About 21 River St

How much is 21 River St, South Yarmouth, MA worth?

The TopHap Estimate for 21 River St, South Yarmouth, MA is $706,538 as of Jul 14, 2026. The likely range is $676,504 to $736,572. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 River St, South Yarmouth, MA last sell?

21 River St, South Yarmouth, MA last sold on Dec 4, 1990 for $130,000, according to the county's recorded deed.

How big is 21 River St, South Yarmouth, MA?

21 River St, South Yarmouth, MA has 3 bedrooms, 2.5 bathrooms, 1,740 square feet of living space and a 0.42-acre lot.

When was 21 River St, South Yarmouth, MA built?

21 River St, South Yarmouth, MA was built in 1780, making it 246 years old. The building has 2 stories.

What schools serve 21 River St, South Yarmouth, MA?

21 River St, South Yarmouth, MA is assigned to Dennis Yarmouth Regional High School (high), rated C; Station Avenue Elementary School (elementary), rated B+; Mattacheese Middle School (middle), rated B-. All sit in Dennis-Yarmouth School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 River St, South Yarmouth, MA compare to other homes in South Yarmouth 02664?

Among the 6,149 homes in South Yarmouth 02664, it is worth more than 53% of them ($706,538 against a typical $697,094), its price per square foot is higher than 5% of them ($406 against a typical $562), it is bigger than 78% of them (1,740 ft² against a typical 1,296 ft²), its lot is bigger than 80% of them (0.42 ac against a typical 0.29 ac) and it is newer than almost none of them (1780 against a typical 1968). Measured against all of Barnstable County, it is worth more than 43% 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 River St, South Yarmouth, MA?

The 2025 property tax bill for 21 River St, South Yarmouth, MA was $3,675. The county assessed it at $519,100.

More homes on River St

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Assigned schools

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