Welcome to 25 South Mill Street — a rare offering of newer construction (built in 2013) located on the waterfront in one of Portsmouth’s most sought-after neighborhoods. This thoughtfully designed two-family home presents a unique opportunity to own a versatile, income-generating property in a premier location. Each of the two units features 2 bedrooms, 1 full bath, and in-unit laundry, offering comfortable, modern living with a coastal flair. The upper unit enjoys elevated views and higher ceilings, maximizing light and enhancing the stunning water vistas. Outdoors, you'll find no shortage of parking with a deep, oversized garage (approx. 14' x 26') and a driveway that accommodates 6+ vehicles — an exceptional amenity for South End living. With flexible use options, this property is ideal for an owner-occupant looking to offset their costs with rental income, investors seeking a premium location asset, or those envisioning a condo conversion or conversion to a single-family residence. The upper unit is currently vacant in order to make showing the property easier (most recently rented in 2025 for $2900/month), while the lower unit is leased through April 2026, providing both immediate flexibility and reliable income. Don’t miss this exceptional opportunity in the heart of the South End — just a short stroll to downtown Portsmouth, Prescott Park, and the city’s vibrant waterfront scene.
Lot & Building Features
UtilitiesPropane
ConstructionClapboard Exterior, Wood Siding
CoolingNone
HeatingHot Water
Parking DescriptionPaved, Garage
SewerPublic
Tax Year2025
Taxes Paid$14,253
WaterPublic
Basement DescriptionUnfinished
FoundationBrick
Lot DescriptionCity Lot
RoofShingle
GarageYes
Community and Schools
Elementary SchoolLittle Harbor School
Junior High SchoolPortsmouth Middle School
Senior High SchoolPortsmouth High School
Unit Features
Unit 1 Baths1
Unit 1 Bedrooms2
Unit 1 Lease TermAnnual
Unit 1 Level Number1
Unit 1 Rental AgreementYes
Unit 1 Rental Amount2600.00
Unit 1 Rental Amt FreqMonthly
Unit 1 Rooms4
Unit 1 StatusLeased
Unit 1 Tenant PaysHeat, Electric
Unit 1 Total Area880
Unit 2 Baths1
Unit 2 Bedrooms2
Unit 2 Level Number2
Unit 2 Rental AgreementNo
Unit 2 Rooms4
Unit 2 StatusVacant
Unit 2 Tenant PaysHeat, Electric
Unit 2 Total Area880
Price History of 25 South Mill Street, Portsmouth, NH
Date
Name
Price
Difference
04/21/2026
Price Adjustment
$1,795,000
2.97%
02/09/2026
Price Adjustment
$1,850,000
5.13%
01/06/2026
Listing Price
$1,950,000
N/A
*Information provided by REWS for your reference only. The accuracy of this information cannot be verified and is not guaranteed.
25 South Mill Street (MLS #5073158) is a multi-family multi-family listing located in Portsmouth, NH.
This multi-family listing is 1,760 sqft and on a lot of 5,227 sqft (or 0.12 acres) with 4 bedrooms, 2 baths and is 13 years old. This property was listed on 01/06/2026 and has been priced for sale at $1,795,000.
Listing Last updated . Some properties which appear for sale on this web site may subsequently have sold or may no longer be available. Walk Score map and data provided by Walk Score. Google map provided by Google. Bing map provided by Microsoft Corporation.
All information provided is deemed reliable but is not guaranteed and should be independently verified.
Listing information courtesy of: Great Island Realty LLC
Copyright 2026 PrimeMLS, Inc. All rights reserved. This information is deemed reliable, but not guaranteed. The data relating to real estate displayed on this display comes in part from the IDX Program of PrimeMLS. The information being provided is for consumers. personal, non- commercial use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. Data last updated 05/18/2026