Browse All Portsmouth NH 6+ Bedroom Properties for Sale

There are properties that simply cannot be replicated. Privately sited on 7.7 waterfront acres on Portsmouth's coveted Shapleigh Island, 518 New Castle Avenue is a once-in-a-generation New England estate, an extraordinary convergence of scale, privacy, architecture, and waterfront living just moments from the heart of downtown Portsmouth. With 13,450± square feet, this magnificent Shingle Style residence was conceived on a grand scale, pairing timeless coastal architecture with exceptional craftsmanship and sophisticated modern living. Georgian-inspired millwork, stately Tuscan columns, intricate wainscoting, and beautifully proportioned interiors create a residence of remarkable presence, while walls of windows capture sweeping water views and an ever-changing maritime landscape. Across 17 rooms, the estate offers 6 bedrooms, 7 full and 2 half baths, and an impressive collection of formal and informal living spaces equally suited for everyday living and grand-scale entertaining. A newly added balcony overlooking the pool creates an elevated vantage point of the estate's sweeping water views. Beyond the home, manicured grounds descend toward the Piscataqua River, where a private deep-water dock provides direct access to Portsmouth Harbor and the open Atlantic beyond. An attached 3-car garage is complemented by a separate 3-car garage with a finished 1-bedroom, 1-bath guest accommodation above, creating a private and flexible retreat for visitors. Nearly 6,000 square feet of unfinished lower-level space offers exceptional flexibility and storage, while a new roof completed in 2025 represents a significant recent improvement. Yet perhaps the estate's greatest luxury is one that cannot be recreated: complete seclusion across 7.7 waterfront acres while remaining connected to downtown Portsmouth and its cultural, culinary, and coastal lifestyle. 518 New Castle Ave is a landmark NH estate and a rare opportunity to steward one of the region's defining legacy properties.

518 New Castle Ave, Portsmouth

$2,100,000

6 Beds ⋅ 6 Baths ⋅ 5099048 MLS

Ideally located on coveted Richards Avenue within the Little Harbour School District, this exceptional residence offers a rare balance of privacy, lush outdoor spaces, and proximity to the best that Portsmouth has to offer. Downtown restaurants, boutique shopping,the waterfront, Prescott Park, and the Farmer's Market are all within easy reach, while nearby athletic fields, the Public Library, and Portsmouth Junior High add everyday convenience just a stone's throw away. Thoughtfully designed gardens create a secluded setting around the home. In the rear, an expansive terrace provides an elegant backdrop for entertaining, leisurely dinners, and evenings outdoors. Gather with family and friends to take in a spectacular view of the Portsmouth Fireworks over Leary Field from a number one vantage point! Beautifully appointed and ideally located, this distinctive property offers a private retreat with the cultural, recreational and civic amenities of Portsmouth just outside your back door.

69 Richards Ave, Portsmouth

$3,600,000

6 Beds ⋅ 6 Baths ⋅ 5095121 MLS

The Pickering-Heffenger House c.1804 Live where history was made and where diplomats, dignitaries, and world leaders once gathered. The Pickering-Heffenger House is one of Portsmouth's most significant residences, prominently featured in Richard Candee's Building Portsmouth and John Mead Howells' Architectural History of the Piscataqua. Its most celebrated chapter occurred in 1905 when Dr. Arthur Heffenger, a retired U.S. Navy physician, hosted members of the Russian delegation during negotiations for the historic Portsmouth Peace Treaty. The grandeur of that era remains evident throughout the home with quadruple crown moldings, marble fireplace mantels, soaring ceilings, and extraordinary millwork. Thoughtfully modernized for today's lifestyle, the residence offers a beautifully appointed granite kitchen, wide-board cherry floors, six bedrooms, and six renovated bathrooms that seamlessly blend historic character with modern comfort. The original carriage house and stable have been transformed into three residences consisting of two one-bedroom apartments and one two-bedroom apartment, creating flexibility for guests, extended family, rental income, or staff accommodations. Perhaps most compelling are the property's future possibilities. It can continue as one of Portsmouth's great private estates, become a multi-generational family compound, or be thoughtfully repositioned as a condominium conversion opportunity. An existing inn license also creates potential for boutique hospitality, subject to approvals. Situated along tree-lined Austin Street and just steps from downtown Portsmouth, this is more than a home, it's an opportunity to own, preserve, and redefine one of the Seacoast's truly iconic properties.

53 Austin St, Portsmouth

Start Your Search

The property listing data and information, or the Images, set forth herein were provided to MLS Property Information Network, Inc. from third party sources, including sellers, lessors, landlords and public records, and were compiled by MLS Property Information Network, Inc. The property listing data and information, and the Images, are for the personal, non commercial use of consumers having a good faith interest in purchasing, leasing or renting listed properties of the type displayed to them and may not be used for any purpose other than to identify prospective properties which such consumers may have a good faith interest in purchasing, leasing or renting. MLS Property Information Network, Inc. and its subscribers disclaim any and all representations and warranties as to the accuracy of the property listing data and information, or as to the accuracy of any of the Images, set forth herein.

board logo 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, noncommercial use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. Data last updated .

6+ Bedroom Portsmouth Real Estate

Our website features the best real estate search for 6+ bedroom properties available in Portsmouth and surrounding areas. It is the only site you will ever need! It is easy-to-use and updated by the official Realtor®’s database every 15 minutes.

You can save searches, and get daily email alerts of new listings, price changes, sold data, and market reports. Our Interactive Map Search allows you to view properties on a map or refine your search by drawing the boundaries around the area you desire.

Curious about what’s happening in your neighborhood? You can create a custom market report to see what’s active, under contract, and sold in your neighborhood!

Considering selling or refinancing your home? Get an INSTANT property valuation now!

Browse All Portsmouth NH 6+ Bedroom Properties for Sale

6+ Bedroom Portsmouth Real Estate

How much is your home worth?

How much is your home worth?