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Single Family ResidenceResidential
$455,119$266 / 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 Oct 21, 2026

521 CASTLEBAY DR

WILLIAMSTOWN, NJ 08094
0
Baths
1,710 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.
0.16 ac
Lot SizeThe size of the land the home sits on, from county records.
2020
Year BuiltThe year the home was originally built, according to county records.

Valuation

$455K
$432K low$478K high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$9,404 (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.$249,500 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$51,600
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$197,900
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$249,500
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$249,500

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.8 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.30%
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.minimal

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
CountyGLOUCESTER
Lot (acres)The size of the land the home sits on, from county records.0.16
PoolWhether the property has a pool, and what kind, such as in-ground.No

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
Holly Glen Elementary SchoolC+
Elementary · Grades KG–4 · 2.5 mi
H
Williamstown High SchoolD+
High · Grades 9–12 · 2.7 mi
M
Williamstown Middle SchoolC
Middle · Grades 5–8 · 3.1 mi

District: Monroe Township School District

Neighborhood · ZIP 08094These 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.101
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 100.64

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.20%
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.1.4%
PopulationHow many people live in this area.42,046
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.755 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$103,564
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$123,493
Average tempThe average temperature here across a full year.55°F
Annual precipHow much rain and melted snow falls here in a typical year.46 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.56%

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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

521 Castlebay 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 72% of homes in Williamstown 08094
  • Costs more per square foot than 91% of homes in Williamstown 08094
  • Has a smaller lot than 85% of homes in Williamstown 08094
  • Newer than 98% of homes in Gloucester County

What homes are worth in Williamstown 08094

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

This home
$197K$659K

This home is worth more than 72% of homes in Williamstown 08094.

How it measures up in Williamstown 08094

The dot is this home. The mark in the middle is the typical home in Williamstown 08094.

Estimated value$455,119
CheaperTypical $356,400Pricier

Pricier than 72% of homes nearby

Price per ft²$266
CheaperTypical $213Pricier

Pricier than 91% of homes nearby

Living area1,710 ft²
SmallerTypical 1,747 ft²Bigger

Bigger than 48% of homes nearby

Lot size0.16 ac
SmallerTypical 0.3 acBigger

Bigger than 15% of homes nearby

Year built2020
OlderTypical 1981Newer

Newer than 96% of homes nearby

How 521 Castlebay Dr ranks against every home in each area.
MeasureThis homeWilliamstown 08094Gloucester County
Estimated valuepricier than$455,11972% of homes69% of homes
Price per ft²pricier than$26691% of homes86% of homes
Living areabigger than1,710 ft²48% of homes46% of homes
Lot sizebigger than0.16 ac15% of homes24% of homes
Year builtnewer than202096% of homes98% of homes

About 521 Castlebay Dr

How much is 521 Castlebay Dr, Williamstown, NJ worth?

The TopHap Estimate for 521 Castlebay Dr, Williamstown, NJ is $455,119 as of Oct 21, 2026. The likely range is $432,212 to $478,026. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 521 Castlebay Dr, Williamstown, NJ last sell?

521 Castlebay Dr, Williamstown, NJ last sold on Jan 1, 1900, according to the county's recorded deed.

How big is 521 Castlebay Dr, Williamstown, NJ?

521 Castlebay Dr, Williamstown, NJ has 1,710 square feet of living space and a 0.16-acre lot.

When was 521 Castlebay Dr, Williamstown, NJ built?

521 Castlebay Dr, Williamstown, NJ was built in 2020, making it 6 years old.

What schools serve 521 Castlebay Dr, Williamstown, NJ?

521 Castlebay Dr, Williamstown, NJ is assigned to Holly Glen Elementary School (elementary), rated C+; Williamstown High School (high), rated D+; Williamstown Middle School (middle), rated C. All sit in Monroe Township School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 521 Castlebay Dr, Williamstown, NJ compare to other homes in Williamstown 08094?

Among the 12,852 homes in Williamstown 08094, it is worth more than 72% of them ($455,119 against a typical $356,400), its price per square foot is higher than 91% of them ($266 against a typical $213), it is bigger than 48% of them (1,710 ft² against a typical 1,747 ft²), its lot is bigger than 15% of them (0.16 ac against a typical 0.3 ac) and it is newer than 96% of them (2020 against a typical 1981). Measured against all of Gloucester County, it is worth more than 69% 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 521 Castlebay Dr, Williamstown, NJ?

The 2025 property tax bill for 521 Castlebay Dr, Williamstown, NJ was $9,404. The county assessed it at $249,500.

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