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CondominiumResidential
$853,265$689 / 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 90How 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 $415,000 on Jan 30, 2020

523 UNION ST

PORTSMOUTH, NH 03801
3
Beds
1.5
Baths
1,239 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.
1900
Year BuiltThe year the home was originally built, according to county records.
3
StoriesHow many floors the home has above ground.
6
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.

Valuation

$853K
$772K low$935K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$415,000 · Jan 30, 2020

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$7,745 (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.$672,900 (2025)
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$672,900
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$659,015

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Condominium
StyleThe architectural style of the home, such as ranch or colonial.Conventional
CountyROCKINGHAM
RoofThe main material covering the roof, such as asphalt shingle or tile.Asphalt
HeatingThe type of heating system in the home.Hot Water
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

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.

M
Portsmouth Middle SchoolA
Middle · Grades 6–8 · 0.5 mi
E
Little Harbour Elementary SchoolA+
Elementary · Grades KG–5 · 0.5 mi
H
Portsmouth High SchoolA
High · Grades 9–12 · 0.5 mi

District: Portsmouth School District

Neighborhood · ZIP 03801These 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.138
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.104
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.98

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.41%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.5.0%
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.24,014
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.808 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$107,161
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$136,932
Average tempThe average temperature here across a full year.48°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.54%

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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

523 Union St 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 83% of homes in Wibird Area
  • Costs more per square foot than 94% of homes in Rockingham County
  • Smaller than 88% of homes in Wibird Area
  • Older than 93% of homes in Rockingham County

What homes are worth in Portsmouth 03801

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

This home
$299K$2.8M

This home is worth more than 51% of homes in Portsmouth 03801.

How it measures up in Portsmouth 03801

The dot is this home. The mark in the middle is the typical home in Portsmouth 03801.

Estimated value$853,265
CheaperTypical $838,484Pricier

Pricier than 51% of homes nearby

Price per ft²$689
CheaperTypical $581Pricier

Pricier than 70% of homes nearby

Living area1,239 ft²
SmallerTypical 1,521 ft²Bigger

Bigger than 34% of homes nearby

Year built1900
OlderTypical 1964Newer

Newer than 19% of homes nearby

How 523 Union St ranks against every home in each area.
MeasureThis homeWibird AreaPortsmouth 03801Rockingham County
Estimated valuepricier than$853,26517% of homes51% of homes79% of homes
Price per ft²pricier than$68942% of homes70% of homes94% of homes
Living areabigger than1,239 ft²12% of homes34% of homes26% of homes
Year builtnewer than190041% of homes19% of homes7% of homes

About 523 Union St

How much is 523 Union St, Portsmouth, NH worth?

The TopHap Estimate for 523 Union St, Portsmouth, NH is $853,265 as of Sep 24, 2026. The likely range is $771,623 to $934,907. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 523 Union St, Portsmouth, NH last sell?

523 Union St, Portsmouth, NH last sold on Jan 30, 2020 for $415,000, according to the county's recorded deed.

How big is 523 Union St, Portsmouth, NH?

523 Union St, Portsmouth, NH has 3 bedrooms, 1.5 bathrooms and 1,239 square feet of living space.

When was 523 Union St, Portsmouth, NH built?

523 Union St, Portsmouth, NH was built in 1900, making it 126 years old. It is a conventional home. The building has 3 stories.

What schools serve 523 Union St, Portsmouth, NH?

523 Union St, Portsmouth, NH is assigned to Portsmouth Middle School (middle), rated A; Little Harbour Elementary School (elementary), rated A+; Portsmouth High School (high), rated A. All sit in Portsmouth School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 523 Union St, Portsmouth, NH compare to other homes in Portsmouth 03801?

Among the 8,130 homes in Portsmouth 03801, it is worth more than 51% of them ($853,265 against a typical $838,484), its price per square foot is higher than 70% of them ($689 against a typical $581), it is bigger than 34% of them (1,239 ft² against a typical 1,521 ft²) and it is newer than 19% of them (1900 against a typical 1964). Measured against all of Rockingham County, it is worth more than 79% 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 523 Union St, Portsmouth, NH?

The 2025 property tax bill for 523 Union St, Portsmouth, NH was $7,745. The county assessed it at $672,900.

More homes on Union St

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More homes in Portsmouth 03801

Assigned schools

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