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Single Family ResidenceResidential
$1,302,575$740 / 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 91How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Aug 30, 2026

15 UNION ST

PORTSMOUTH, NH 03801
4
Beds
1.5
Baths
1,761 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.
1,742 ft²
Lot SizeThe size of the land the home sits on, from county records.
1870
Year BuiltThe year the home was originally built, according to county records.
3
StoriesHow many floors the home has above ground.
7
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.

Valuation

$1.3M
$1.2M low$1.4M high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$8,191 (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.$711,600 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$433,900
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$277,700
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$1,523,230

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountyROCKINGHAM
Lot (acres)The size of the land the home sits on, from county records.0.04
RoofThe main material covering the roof, such as asphalt shingle or tile.Asphalt
HeatingThe type of heating system in the home.Steam
PoolWhether the property has a pool, and what kind, such as in-ground.No

Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.

M
Portsmouth Middle SchoolB
Middle · Grades 6–8 · 0.4 mi
E
Little Harbour Elementary SchoolA
Elementary · Grades KG–5 · 0.8 mi
H
Portsmouth High SchoolA+
High · Grades 9–12 · 0.9 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

15 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 more than 95% of homes in Rockingham County
  • Costs more per square foot than 96% of homes in Rockingham County
  • Among the smallest lots in Portsmouth 03801
  • Older than 97% 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
$278K$2.7M

This home is worth more than 80% 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$1,302,575
CheaperTypical $802,944Pricier

Pricier than 80% of homes nearby

Price per ft²$740
CheaperTypical $554Pricier

Pricier than 78% of homes nearby

Living area1,761 ft²
SmallerTypical 1,526 ft²Bigger

Bigger than 61% of homes nearby

Lot size1,742 ft²
SmallerTypical 0.22 acBigger

Smaller than almost all homes nearby

Year built1870
OlderTypical 1963Newer

Newer than 9% of homes nearby

How 15 Union St ranks against every home in each area.
MeasureThis homeGoodwin ParkPortsmouth 03801Rockingham County
Estimated valuepricier than$1,302,57588% of homes80% of homes95% of homes
Price per ft²pricier than$74083% of homes78% of homes96% of homes
Living areabigger than1,761 ft²57% of homes61% of homes50% of homes
Lot sizebigger than1,742 ft²4% of homesalmost no homes3% of homes
Year builtnewer than187038% of homes9% of homes3% of homes

About 15 Union St

How much is 15 Union St, Portsmouth, NH worth?

The TopHap Estimate for 15 Union St, Portsmouth, NH is $1,302,575 as of Aug 30, 2026. The likely range is $1,184,959 to $1,420,191. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 15 Union St, Portsmouth, NH last sell?

15 Union St, Portsmouth, NH last sold on Jan 1, 1900, according to the county's recorded deed.

How big is 15 Union St, Portsmouth, NH?

15 Union St, Portsmouth, NH has 4 bedrooms, 1.5 bathrooms, 1,761 square feet of living space and a 0.04-acre lot.

When was 15 Union St, Portsmouth, NH built?

15 Union St, Portsmouth, NH was built in 1870, making it 156 years old. The building has 3 stories.

What schools serve 15 Union St, Portsmouth, NH?

15 Union St, Portsmouth, NH is assigned to Portsmouth Middle School (middle), rated B; 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 15 Union St, Portsmouth, NH compare to other homes in Portsmouth 03801?

Among the 8,130 homes in Portsmouth 03801, it is worth more than 80% of them ($1,302,575 against a typical $802,944), its price per square foot is higher than 78% of them ($740 against a typical $554), it is bigger than 61% of them (1,761 ft² against a typical 1,526 ft²), its lot is bigger than almost none of them (1,742 ft² against a typical 0.22 ac) and it is newer than 9% of them (1870 against a typical 1963). Measured against all of Rockingham 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 15 Union St, Portsmouth, NH?

The 2025 property tax bill for 15 Union St, Portsmouth, NH was $8,191. The county assessed it at $711,600.

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