Skip to content
Skip to content
TopHapOpen in map
CondominiumResidential

51 Islington St

PORTSMOUTH, NH 03801
2011
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
Built 20115 floors26 units742–3,081 ft²
$31M
All units combinedThe sum of our current value estimates for every unit in the building — roughly what the whole building's homes are worth together.
$1.1M
Median unit valueThe middle unit value in this building by our estimate: half the units are worth more, half less.
$877
Median $/ft²The middle price per square foot across the building's units, by our current estimates. Useful for comparing units of different sizes.

+11.4%vs the Portsmouth ZIP median sale $/ft² ($787)

Sales Performance

$1.3M
Median sale (12 mo)The middle sale price among this building's units that sold in the last 12 months, from recorded deeds.
+40.4%
1-yr changeHow the building's median sale price over the last 12 months compares with the 12 months before that.
2
Sales (12 mo)Units in this building that sold in the last 12 months, from recorded arms-length deeds.
7.7%
Turnover (12 mo)The share of units that changed hands in the last 12 months. Around 4–6% a year is typical; much higher can signal investor churn or a wave of exits.
Median sale price (yearly, all time)Every recorded arms-length sale in the building since records begin, grouped by year: the bars count sales and the line tracks the median price paid.MedianSales
20212022202420252026
Sale price per ft² (yearly, all time)The middle price per square foot across the building's units, by our current estimates. Useful for comparing units of different sizes.$/ft²
20212022202420252026

8 arms-length sales on record for this building.

Unit Mix & Floor PlansThe building's recurring floor plans, found by grouping units with identical beds, baths and square footage in county records. Larger groups are the building's standard layouts; leftover units have one-off sizes.

Every unit: size vs estimated valueEvery unit in the building as one dot: across is its size, up is our current value estimate, and color is its bedroom count. Vertical columns of dots are recurring floor plans; the height spread within a column shows how much floor, view and condition move prices for the same layout.
$653K$1.4M$2.1M$2.8M742 ft²1,210 ft²1,678 ft²2,145 ft²2,613 ft²3,081 ft²
1 bd2 bd3 bd
1 bed
2 units
2 bed
20 units
3 bed
4 units
Recurring floor plansThe building's recurring floor plans, found by grouping units with identical beds, baths and square footage in county records. Larger groups are the building's standard layouts; leftover units have one-off sizes.
2 bd · 2 ba · 1,084 ft²
2 units
2 bd · 2.5 ba · 1,519 ft²
2 units
One-off layouts
22 units

Value DistributionHow the building's units spread across value ranges by our current estimates. A wide spread usually means big differences in size, floor or view.

$653K–$874K
4 units
$934K–$1.2M
12 units
$1.2M–$1.4M
7 units
$1.5M–$1.7M
2 units
$2.8M–$2.8M
1 unit

Value by Floor & LineAverage estimated price per square foot by floor range, using unit numbers to infer floors. Higher floors usually price higher — the gap shows how much the view is worth here.

Floor 2
$862/ft²
Floor 3
$865/ft²
Floor 4
$901/ft²
Floor 5
$876/ft²
Unit lines by $/ft²Condo units stacked vertically share a unit line — the last digits of the unit number (like 05 in 1205, 1305, 1405). Lines share a layout and exposure, so comparing estimated $/ft² by line shows which position in the building commands a premium.
Line ·05
$956/ft²
Line ·04
$919/ft²
Line ·01
$905/ft²
Line ·02
$900/ft²
Line ·03
$853/ft²
Line ·06
$790/ft²
Line ·07
$787/ft²

Ownership & Financing

Owner-occupiedThe share of units where the owner lives in the unit, per county records. The rest are second homes or rentals.58%
Company-ownedUnits owned through an LLC, trust, or other company — a rough proxy for investor ownership.31%
Typical owner tenureThe middle number of years since each unit last changed hands — how long the current owners have been in place.9.7 yrs
Cash purchases (5 yrs)The share of purchases in the last 5 years with no mortgage recorded. High cash share is common in second-home and investor buildings.100%
Avg. loan-to-valueAverage current loan balance against unit value across the building. Low numbers mean owners hold lots of equity — a sign of financial stability.18%
Median owner equityThe middle dollar amount of equity (value minus loans) unit owners hold in this building.$1,000,542
Median tax billThe middle annual property tax bill among the building's units.$10,221
Pre-foreclosure noticesUnits with an active pre-foreclosure or foreclosure notice on file.0

Recent SalesThe latest recorded arms-length sales in the building, newest first.

Unit 201Oct 9, 2026$1,112,533Unit 406Dec 16, 2025$1,400,000Unit 204Jan 10, 2025$895,000Unit 1BApr 11, 2024$1,249,000Unit 401Apr 2, 2024$1,240,000Unit 1BNov 7, 2022$1,249,000Unit 301Sep 27, 2022$863,533Unit 401Jul 20, 2021$840,000

Values are TopHap estimates, not appraisals. Sales, ownership and tax figures come from recorded county documents via ATTOM and can lag by several weeks.

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.Condo/Apartment
CountyROCKINGHAM
RoofThe main material covering the roof, such as asphalt shingle or tile.Asphalt
HeatingThe type of heating system in the home.Forced Air With Air Conditioning
CoolingThe type of cooling or air conditioning in the home.Yes
FireplaceWhether the home has a fireplace, and what kind.Yes
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 · 0.2 mi
E
Little Harbour Elementary SchoolA+
Elementary · Grades KG–5 · 0.8 mi
H
Portsmouth High SchoolA
High · Grades 9–12 · 1.1 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%

All UnitsEvery property record the county has at this street address, such as the units in a condo building. Prices shown are our estimates, not asking prices.

51 Islington St # 1b
2 bd · 2 ba · 2,118 ft²
$1.4M
51 Islington St # 201
2 bd · 2 ba · 1,414 ft²
$1.2M
51 Islington St # 202
1 bd · 1 ba · 742 ft²
$653K
51 Islington St # 203
3 bd · 2 ba · 1,359 ft²
$1.2M
51 Islington St # 204
2 bd · 2 ba · 1,084 ft²
$874K
51 Islington St # 205
2 bd · 2 ba · 1,156 ft²
$1M
51 Islington St # 206
2 bd · 2 ba · 1,527 ft²
$1.3M
51 Islington St # 207
3 bd · 3 ba · 1,891 ft²
$1.7M
51 Islington St # 301
2 bd · 2 ba · 1,294 ft²
$1.1M
51 Islington St # 302
2 bd · 2 ba · 941 ft²
$934K
51 Islington St # 303
2 bd · 2 ba · 1,284 ft²
$1.1M
51 Islington St # 304
2 bd · 2 ba · 1,084 ft²
$963K
51 Islington St # 305
2 bd · 2 ba · 1,158 ft²
$1.1M
51 Islington St # 306
3 bd · 2 ba · 1,891 ft²
$1.2M
51 Islington St # 307
2 bd · 2.5 ba · 1,519 ft²
$1.3M
51 Islington St # 401
2 bd · 2 ba · 1,211 ft²
$1.2M
51 Islington St # 402
2 bd · 2 ba · 899 ft²
$835K
51 Islington St # 403
2 bd · 2 ba · 1,228 ft²
$975K
51 Islington St # 404
2 bd · 2 ba · 1,028 ft²
$1.1M
51 Islington St # 405
1 bd · 1 ba · 799 ft²
$805K
51 Islington St # 406
2 bd · 2 ba · 1,547 ft²
$1.4M
51 Islington St # 407
2 bd · 2 ba · 1,833 ft²
$1.2M
51 Islington St # 501
3 bd · 4.5 ba · 3,081 ft²
$2.8M
51 Islington St # 502
2 bd · 2.5 ba · 1,519 ft²
$1.2M
51 Islington St # 503
2 bd · 2.5 ba · 1,761 ft²
$1.5M
51 Islington St # 504
2 bd · 2 ba · 1,142 ft²
$1M

Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.

About 51 Islington St

How many units are in 51 Islington St, Portsmouth, NH?

51 Islington St, Portsmouth, NH has 26 residential units across 5 floors, built in 2011, according to county assessor records.

What is a unit at 51 Islington St, Portsmouth, NH worth?

The median TopHap Estimate across the 26 units at 51 Islington St, Portsmouth, NH is $1,137,783. That works out to $877 per square foot. Units run from 742 to 3,081 square feet. Estimates are modelled from recorded sales and assessments, not appraisals.

Is 51 Islington St, Portsmouth, NH expensive for Portsmouth?

Units at 51 Islington St, Portsmouth, NH carry a median of $877 per square foot, 11% above the Portsmouth median of $787 per square foot.

How often do units sell at 51 Islington St, Portsmouth, NH?

2 units at 51 Islington St, Portsmouth, NH sold in the last 12 months, out of 8 recorded arms-length sales all time. That is a turnover rate of 7.7% of the building per year. The median sale over that period was $1.3M.

What floor plans does 51 Islington St, Portsmouth, NH have?

The most common plan at 51 Islington St, Portsmouth, NH is a 2-bedroom of 1,084 square feet, repeated 2 times, with a median estimate of $918,428. TopHap identifies 2 recurring plans in the building.

More homes on Islington St

Closest homes

More homes in Portsmouth 03801

Assigned schools

Explore the area

See this home in context

Open 51 Islington 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