Skip to content
Skip to content
TopHapOpen in map
Single Family ResidenceResidential
$852,604$251 / 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 95How 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 $579,900 on Feb 13, 2017

4040 HOLLY KNOLL DR

GLEN ARM, MD 21057
3 / 1
Baths
3,397 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.
1.09 ac
Lot SizeThe size of the land the home sits on, from county records.
1978
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.
2
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$853K
$811K low$894K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$579,900 · Feb 13, 2017

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$7,939 (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.$650,100 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$196,700
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$453,400
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$629,300
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$650,100

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.Conventional
CountyBaltimore
Lot (acres)The size of the land the home sits on, from county records.1.09
RoofThe main material covering the roof, such as asphalt shingle or tile.Composition Shingle
HeatingThe type of heating system in the home.Forced Air
CoolingThe type of cooling or air conditioning in the home.Yes
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 · 288 ft²Porch · 80 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
Carroll Manor Elementary SchoolA+
Elementary · Grades PK–5 · 0.9 mi
H
Dulaney High SchoolB-
High · Grades 9–12 · 4.7 mi
M
Cockeysville Middle SchoolB-
Middle · Grades 6–8 · 5.4 mi

District: Baltimore County Public Schools

Neighborhood · ZIP 21057These 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.74
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.88
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.47

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.31%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.3.8%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.0%
PopulationHow many people live in this area.4,918
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.295 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$156,114
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$167,405
Average tempThe average temperature here across a full year.55°F
Annual precipHow much rain and melted snow falls here in a typical year.47 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.57%

Owner Tools

Do you own this home?
Claim this home

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

4040 Holly 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.

  • Worth more than 95% of homes in Baltimore County
  • Bigger than 94% of homes in Baltimore County
  • Has a bigger lot than 89% of homes in Baltimore County
  • Newer than 74% of homes in Glen Arm 21057

What homes are worth in Glen Arm 21057

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

This home
$299K$1.2M

This home is worth more than 89% of homes in Glen Arm 21057.

How it measures up in Glen Arm 21057

The dot is this home. The mark in the middle is the typical home in Glen Arm 21057.

Estimated value$852,604
CheaperTypical $638,091Pricier

Pricier than 89% of homes nearby

Price per ft²$251
CheaperTypical $261Pricier

Pricier than 43% of homes nearby

Living area3,397 ft²
SmallerTypical 2,388 ft²Bigger

Bigger than 83% of homes nearby

Lot size1.09 ac
SmallerTypical 1.51 acBigger

Bigger than 29% of homes nearby

Year built1978
OlderTypical 1969Newer

Newer than 74% of homes nearby

How 4040 Holly Knoll Dr ranks against every home in each area.
MeasureThis homeGlen Arm 21057Baltimore County
Estimated valuepricier than$852,60489% of homes95% of homes
Price per ft²pricier than$25143% of homes63% of homes
Living areabigger than3,397 ft²83% of homes94% of homes
Lot sizebigger than1.09 ac29% of homes89% of homes
Year builtnewer than197874% of homes62% of homes

About 4040 Holly Knoll Dr

How much is 4040 Holly Knoll Dr, Glen Arm, MD worth?

The TopHap Estimate for 4040 Holly Knoll Dr, Glen Arm, MD is $852,604 as of Sep 24, 2026. The likely range is $811,121 to $894,087. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 4040 Holly Knoll Dr, Glen Arm, MD last sell?

4040 Holly Knoll Dr, Glen Arm, MD last sold on Feb 13, 2017 for $579,900, according to the county's recorded deed.

How big is 4040 Holly Knoll Dr, Glen Arm, MD?

4040 Holly Knoll Dr, Glen Arm, MD has 3 bathrooms, 3,397 square feet of living space and a 1.09-acre lot.

When was 4040 Holly Knoll Dr, Glen Arm, MD built?

4040 Holly Knoll Dr, Glen Arm, MD was built in 1978, making it 48 years old. It is a conventional home. The building has 2 stories.

What schools serve 4040 Holly Knoll Dr, Glen Arm, MD?

4040 Holly Knoll Dr, Glen Arm, MD is assigned to Carroll Manor Elementary School (elementary), rated A+; Dulaney High School (high), rated B-; Cockeysville Middle School (middle), rated B-. All sit in Baltimore County Public Schools. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 4040 Holly Knoll Dr, Glen Arm, MD compare to other homes in Glen Arm 21057?

Among the 1,461 homes in Glen Arm 21057, it is worth more than 89% of them ($852,604 against a typical $638,091), its price per square foot is higher than 43% of them ($251 against a typical $261), it is bigger than 83% of them (3,397 ft² against a typical 2,388 ft²), its lot is bigger than 29% of them (1.09 ac against a typical 1.51 ac) and it is newer than 74% of them (1978 against a typical 1969). Measured against all of Baltimore County, it is worth more than 95% 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 4040 Holly Knoll Dr, Glen Arm, MD?

The 2025 property tax bill for 4040 Holly Knoll Dr, Glen Arm, MD was $7,939. The county assessed it at $650,100.

More homes on Holly Knoll Dr

Closest homes

More homes in Glen Arm 21057

Assigned schools

Explore the area

See this home in context

Open 4040 Holly Knoll Dr on TopHap’s interactive map to compare it against every sale nearby, overlay school zones and flood risk, and run a CMA.

Open in map
A flyover of TopHap's photorealistic 3D map, with recorded sale prices pinned to homes
Search any address, city, zip, or county…3D$1.9M$6.25MOpen in map