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Single Family ResidenceResidential
$428,960$302 / 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 89How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Sep 24, 2026
Last sold for $162,300 on Sep 16, 2020

509 PROSPECT RD

MOUNT AIRY, MD 21771
2.5
Baths
1,420 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.
0.41 ac
Lot SizeThe size of the land the home sits on, from county records.
1972
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
2
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$429K
$382K low$476K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$162,300 · Sep 16, 2020

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$4,673 (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.$346,600 (2026)
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$323,300
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$369,900

Climate Risk

Overall riskThe average of the five hazard scores below, on a 0 to 100 scale. Higher means greater projected risk over the coming decades.43
1
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
14
WildfireProjected wildfire risk, scored 0 to 100, based on how much land burns in a typical year. Higher is riskier.
75
HeatProjected heat risk, scored 0 to 100, based on how many extremely hot days a year are expected. Higher is riskier.
90
StormProjected risk from heavy rainstorms, scored 0 to 100, based on how often extreme rainfall is expected. Higher is riskier.
37
DroughtProjected water shortage risk, scored 0 to 100. Higher means more strain on the local water supply.

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.Split Foyer
CountyFREDERICK
Lot (acres)The size of the land the home sits on, from county records.0.41
RoofThe main material covering the roof, such as asphalt shingle or tile.Composition Shingle
HeatingThe type of heating system in the home.Electric
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 · 320 ft²Patio · 90 ft²

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
Twin Ridge Elementary SchoolA+
Elementary · Grades KG–5 · 1.1 mi
H
Linganore High SchoolB
High · Grades 9–12 · 5.9 mi
M
Windsor Knolls Middle SchoolA-
Middle · Grades 6–8 · 7.4 mi

District: Frederick County Public Schools

Neighborhood · ZIP 21771These 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.59
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.82
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.37

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.97%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.29%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.3.1%
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.32,505
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.382 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$151,406
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$162,296
Average tempThe average temperature here across a full year.53°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

509 Prospect Rd 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 86% of homes in Mount Airy 21771
  • Costs more per square foot than 90% of homes in Frederick County
  • Smaller than 83% of homes in Frederick County
  • Has a smaller lot than 73% of homes in Mount Airy 21771
  • Older than 82% of homes in Mount Airy 21771

What homes are worth in Mount Airy 21771

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

This home
$318K$1.1M

This home is worth more than 14% of homes in Mount Airy 21771.

How it measures up in Mount Airy 21771

The dot is this home. The mark in the middle is the typical home in Mount Airy 21771.

Estimated value$428,960
CheaperTypical $605,835Pricier

Pricier than 14% of homes nearby

Price per ft²$302
CheaperTypical $281Pricier

Pricier than 64% of homes nearby

Living area1,420 ft²
SmallerTypical 2,194 ft²Bigger

Bigger than 18% of homes nearby

Lot size0.41 ac
SmallerTypical 0.95 acBigger

Bigger than 27% of homes nearby

Year built1972
OlderTypical 1988Newer

Newer than 18% of homes nearby

How 509 Prospect Rd ranks against every home in each area.
MeasureThis homeMount Airy 21771Frederick County
Estimated valuepricier than$428,96014% of homes38% of homes
Price per ft²pricier than$30264% of homes90% of homes
Living areabigger than1,420 ft²18% of homes17% of homes
Lot sizebigger than0.41 ac27% of homes66% of homes
Year builtnewer than197218% of homes24% of homes

About 509 Prospect Rd

How much is 509 Prospect Rd, Mount Airy, MD worth?

The TopHap Estimate for 509 Prospect Rd, Mount Airy, MD is $428,960 as of Sep 24, 2026. The likely range is $381,766 to $476,154. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 509 Prospect Rd, Mount Airy, MD last sell?

509 Prospect Rd, Mount Airy, MD last sold on Sep 16, 2020 for $162,300, according to the county's recorded deed.

How big is 509 Prospect Rd, Mount Airy, MD?

509 Prospect Rd, Mount Airy, MD has 2.5 bathrooms, 1,420 square feet of living space and a 0.41-acre lot.

When was 509 Prospect Rd, Mount Airy, MD built?

509 Prospect Rd, Mount Airy, MD was built in 1972, making it 54 years old. It is a split foyer home. The building has 1 story.

What schools serve 509 Prospect Rd, Mount Airy, MD?

509 Prospect Rd, Mount Airy, MD is assigned to Twin Ridge Elementary School (elementary), rated A+; Linganore High School (high), rated B; Windsor Knolls Middle School (middle), rated A-. All sit in Frederick County Public Schools. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 509 Prospect Rd, Mount Airy, MD compare to other homes in Mount Airy 21771?

Among the 10,756 homes in Mount Airy 21771, it is worth more than 14% of them ($428,960 against a typical $605,835), its price per square foot is higher than 64% of them ($302 against a typical $281), it is bigger than 18% of them (1,420 ft² against a typical 2,194 ft²), its lot is bigger than 27% of them (0.41 ac against a typical 0.95 ac) and it is newer than 18% of them (1972 against a typical 1988). Measured against all of Frederick County, it is worth more than 38% 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 Prospect Rd, Mount Airy, MD?

The 2025 property tax bill for 509 Prospect Rd, Mount Airy, MD was $4,673. The county assessed it at $346,600.

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