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TownhouseResidential
$428,346$301 / 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 $297,000 on Mar 11, 2021

20421 BOULDER RIDGE TER

GAITHERSBURG, MD 20879
2.5
Baths
1,422 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.
2,310 ft²
Lot SizeThe size of the land the home sits on, from county records.
1993
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.

Valuation

$428K
$400K low$457K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$297,000 · Mar 11, 2021

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$4,396 (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.$382,000 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$144,000
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$238,000
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$343,967
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$382,000

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Townhouse
StyleThe architectural style of the home, such as ranch or colonial.Townhouse
CountyMONTGOMERY
Lot (acres)The size of the land the home sits on, from county records.0.05
RoofThe main material covering the roof, such as asphalt shingle or tile.Composition Shingle
HeatingThe type of heating system in the home.Yes
CoolingThe type of cooling or air conditioning in the home.Central
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 · 160 ft²

Transaction History(1)

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
Goshen Elementary SchoolC+
Elementary · Grades KG–5 · 0.9 mi
M
Forest Oak Middle SchoolD-
Middle · Grades 6–8 · 2.7 mi
H
Gaithersburg High SchoolD
High · Grades 9–12 · 4.0 mi

District: Montgomery County Public Schools

Neighborhood · ZIP 20879These 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.77
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.86
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.39

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.98%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.24%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.10%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.0.9%
PopulationHow many people live in this area.29,513
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.3,576 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$104,978
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$132,194
Average tempThe average temperature here across a full year.54°F
Annual precipHow much rain and melted snow falls here in a typical year.44 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.57%

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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

20421 Boulder Ridge Ter 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 77% of homes in Montgomery County
  • Costs more per square foot than 77% of homes in Gaithersburg 20879
  • Smaller than 74% of homes in Montgomery County
  • Has a smaller lot than 72% of homes in Montgomery County
  • Newer than 91% of homes in Gaithersburg 20879

What homes are worth in Gaithersburg 20879

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

This home
$174K$1.1M

This home is worth more than 46% of homes in Gaithersburg 20879.

How it measures up in Gaithersburg 20879

The dot is this home. The mark in the middle is the typical home in Gaithersburg 20879.

Estimated value$428,346
CheaperTypical $438,498Pricier

Pricier than 46% of homes nearby

Price per ft²$301
CheaperTypical $260Pricier

Pricier than 77% of homes nearby

Living area1,422 ft²
SmallerTypical 1,584 ft²Bigger

Bigger than 40% of homes nearby

Lot size2,310 ft²
SmallerTypical 2,701 ft²Bigger

Bigger than 43% of homes nearby

Year built1993
OlderTypical 1985Newer

Newer than 91% of homes nearby

How 20421 Boulder Ridge Ter ranks against every home in each area.
MeasureThis homeGaithersburg 20879Montgomery County
Estimated valuepricier than$428,34646% of homes23% of homes
Price per ft²pricier than$30177% of homes49% of homes
Living areabigger than1,422 ft²40% of homes26% of homes
Lot sizebigger than2,310 ft²43% of homes28% of homes
Year builtnewer than199391% of homes77% of homes

About 20421 Boulder Ridge Ter

How much is 20421 Boulder Ridge Ter, Gaithersburg, MD worth?

The TopHap Estimate for 20421 Boulder Ridge Ter, Gaithersburg, MD is $428,346 as of Aug 30, 2026. The likely range is $399,701 to $456,991. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 20421 Boulder Ridge Ter, Gaithersburg, MD last sell?

20421 Boulder Ridge Ter, Gaithersburg, MD last sold on Mar 11, 2021 for $297,000, according to the county's recorded deed.

How big is 20421 Boulder Ridge Ter, Gaithersburg, MD?

20421 Boulder Ridge Ter, Gaithersburg, MD has 2.5 bathrooms, 1,422 square feet of living space and a 0.05-acre lot.

When was 20421 Boulder Ridge Ter, Gaithersburg, MD built?

20421 Boulder Ridge Ter, Gaithersburg, MD was built in 1993, making it 33 years old. It is a townhouse home. The building has 2 stories.

What schools serve 20421 Boulder Ridge Ter, Gaithersburg, MD?

20421 Boulder Ridge Ter, Gaithersburg, MD is assigned to Goshen Elementary School (elementary), rated C+; Forest Oak Middle School (middle), rated D-; Gaithersburg High School (high), rated D. All sit in Montgomery County Public Schools. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 20421 Boulder Ridge Ter, Gaithersburg, MD compare to other homes in Gaithersburg 20879?

Among the 7,859 homes in Gaithersburg 20879, it is worth more than 46% of them ($428,346 against a typical $438,498), its price per square foot is higher than 77% of them ($301 against a typical $260), it is bigger than 40% of them (1,422 ft² against a typical 1,584 ft²), its lot is bigger than 43% of them (2,310 ft² against a typical 2,701 ft²) and it is newer than 91% of them (1993 against a typical 1985). Measured against all of Montgomery County, it is worth more than 23% 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 20421 Boulder Ridge Ter, Gaithersburg, MD?

The 2025 property tax bill for 20421 Boulder Ridge Ter, Gaithersburg, MD was $4,396. The county assessed it at $382,000.

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