Skip to content
Skip to content
TopHapOpen in map
CondominiumResidential
$596,836$879 / 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 74How 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 $215,000 on May 31, 2017

425 UNION ST

PORTSMOUTH, NH 03801
Building report
1
Beds
1
Baths
679 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.
3
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.

Valuation

$597K
$444K low$750K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$215,000 · May 31, 2017

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$4,450 (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.$386,600 (2025)
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$386,600
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$622,725

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

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 · 0.4 mi
E
Little Harbour Elementary SchoolA+
Elementary · Grades KG–5 · 0.5 mi
H
Portsmouth High SchoolA
High · Grades 9–12 · 0.6 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%

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

425 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 97% of homes in Wibird Area
  • Costs more per square foot than 98% of homes in Rockingham County
  • Among the smallest 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 24% 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$596,836
CheaperTypical $838,484Pricier

Pricier than 24% of homes nearby

Price per ft²$879
CheaperTypical $581Pricier

Pricier than 87% of homes nearby

Living area679 ft²
SmallerTypical 1,521 ft²Bigger

Bigger than 4% of homes nearby

Year built1900
OlderTypical 1964Newer

Newer than 19% of homes nearby

How 425 Union St ranks against every home in each area.
MeasureThis homeWibird AreaPortsmouth 03801Rockingham County
Estimated valuepricier than$596,8363% of homes24% of homes44% of homes
Price per ft²pricier than$87982% of homes87% of homes98% of homes
Living areabigger than679 ft²almost no homes4% of homes5% of homes
Year builtnewer than190041% of homes19% of homes7% of homes

About 425 Union St

How much is 425 Union St, Portsmouth, NH worth?

The TopHap Estimate for 425 Union St, Portsmouth, NH is $596,836 as of Sep 24, 2026. The likely range is $443,908 to $749,764. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 425 Union St, Portsmouth, NH last sell?

425 Union St, Portsmouth, NH last sold on May 31, 2017 for $215,000, according to the county's recorded deed.

How big is 425 Union St, Portsmouth, NH?

425 Union St, Portsmouth, NH has 1 bedrooms, 1 bathrooms and 679 square feet of living space.

When was 425 Union St, Portsmouth, NH built?

425 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 425 Union St, Portsmouth, NH?

425 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 425 Union St, Portsmouth, NH compare to other homes in Portsmouth 03801?

Among the 8,130 homes in Portsmouth 03801, it is worth more than 24% of them ($596,836 against a typical $838,484), its price per square foot is higher than 87% of them ($879 against a typical $581), it is bigger than 4% of them (679 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 44% 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 425 Union St, Portsmouth, NH?

The 2025 property tax bill for 425 Union St, Portsmouth, NH was $4,450. The county assessed it at $386,600.

More homes on Union St

Closest homes

More homes in Portsmouth 03801

Assigned schools

Explore the area

See this home in context

Open 425 Union St 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