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TownhouseResidential
$681,358$411 / 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 Jul 14, 2026

509 OAK KNOLL DR

ROCKVILLE, MD 20850
3.5
Baths
1,656 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.
1,089 ft²
Lot SizeThe size of the land the home sits on, from county records.
2002
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.
1
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$681K
$633K low$730K high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$7,917 (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.$618,567 (2026)
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$593,133
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$644,000

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.0.03
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.Composition Shingle
HeatingThe type of heating system in the home.Yes
CoolingThe type of cooling or air conditioning in the home.Central
FireplaceWhether the home has a fireplace, and what kind.Yes
GarageWhether the property has a garage, and details like whether it is attached to the home.Garage, Attached
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 · 122 ft²

Transaction History(4)

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
Julius West Middle SchoolA
Middle · Grades 6–8 · 2.0 mi
E
Ritchie Park Elementary SchoolA-
Elementary · Grades KG–5 · 2.4 mi
H
Richard Montgomery High SchoolA-
High · Grades 9–12 · 2.7 mi

District: Montgomery County Public Schools

Neighborhood · ZIP 20850These 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.104
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.89
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.40

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.95%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.28%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.7.8%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.0.8%
PopulationHow many people live in this area.51,693
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.3,703 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$126,425
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$154,183
Average tempThe average temperature here across a full year.54°F
Annual precipHow much rain and melted snow falls here in a typical year.43 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.57%

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

509 Oak Knoll Dr 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 83% of homes in Montgomery County
  • Smaller than 65% of homes in Rockville 20850
  • Has a smaller lot than 92% of homes in Montgomery County
  • Newer than 88% of homes in Montgomery County

What homes are worth in Rockville 20850

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

This home
$181K$1.6M

This home is worth more than 41% of homes in Rockville 20850.

How it measures up in Rockville 20850

The dot is this home. The mark in the middle is the typical home in Rockville 20850.

Estimated value$681,358
CheaperTypical $769,254Pricier

Pricier than 41% of homes nearby

Price per ft²$411
CheaperTypical $340Pricier

Pricier than 81% of homes nearby

Living area1,656 ft²
SmallerTypical 2,048 ft²Bigger

Bigger than 35% of homes nearby

Lot size1,089 ft²
SmallerTypical 4,138 ft²Bigger

Bigger than 13% of homes nearby

Year built2002
OlderTypical 1991Newer

Newer than 79% of homes nearby

How 509 Oak Knoll Dr ranks against every home in each area.
MeasureThis homeRockvilleRockville 20850Montgomery County
Estimated valuepricier than$681,35852% of homes41% of homes55% of homes
Price per ft²pricier than$41179% of homes81% of homes83% of homes
Living areabigger than1,656 ft²40% of homes35% of homes36% of homes
Lot sizebigger than1,089 ft²10% of homes13% of homes8% of homes
Year builtnewer than200283% of homes79% of homes88% of homes

About 509 Oak Knoll Dr

How much is 509 Oak Knoll Dr, Rockville, MD worth?

The TopHap Estimate for 509 Oak Knoll Dr, Rockville, MD is $681,358 as of Jul 14, 2026. The likely range is $632,612 to $730,104. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 509 Oak Knoll Dr, Rockville, MD last sell?

509 Oak Knoll Dr, Rockville, MD last sold on Oct 16, 2008, according to the county's recorded deed. TopHap holds 2 recorded sales for this parcel.

How big is 509 Oak Knoll Dr, Rockville, MD?

509 Oak Knoll Dr, Rockville, MD has 3.5 bathrooms, 1,656 square feet of living space and a 0.03-acre lot.

When was 509 Oak Knoll Dr, Rockville, MD built?

509 Oak Knoll Dr, Rockville, MD was built in 2002, making it 24 years old. It is a townhouse home. The building has 2 stories.

What schools serve 509 Oak Knoll Dr, Rockville, MD?

509 Oak Knoll Dr, Rockville, MD is assigned to Julius West Middle School (middle), rated A; Ritchie Park Elementary School (elementary), rated A-; Richard Montgomery High School (high), rated A-. All sit in Montgomery County Public Schools. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 509 Oak Knoll Dr, Rockville, MD compare to other homes in Rockville 20850?

Among the 14,094 homes in Rockville 20850, it is worth more than 41% of them ($681,358 against a typical $769,254), its price per square foot is higher than 81% of them ($411 against a typical $340), it is bigger than 35% of them (1,656 ft² against a typical 2,048 ft²), its lot is bigger than 13% of them (1,089 ft² against a typical 4,138 ft²) and it is newer than 79% of them (2002 against a typical 1991). Measured against all of Montgomery County, it is worth more than 55% 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 509 Oak Knoll Dr, Rockville, MD?

The 2025 property tax bill for 509 Oak Knoll Dr, Rockville, MD was $7,917. The county assessed it at $618,567.

More homes on Oak Knoll Dr

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Assigned schools

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