Portsmouth, NH Cathartes and its joint venture partner, Chinburg Builders Inc., have begun construction on a new waterfront luxury condominium project at 53 Green St. known as The Maris. The mixed-use development will feature 45 residential units with 2,600 s/f of commercial space on its ground level. It will be the city’s only downtown residential community with amenities including an onsite concierge service. In addition, The Maris will create open community space along the North Mill Pond, public art and a walking path as part of the North Mill Pond Trail and Greenway.

“We are excited to introduce The Maris, a mixed-use community inspired by Portsmouth’s deep cultural history,” said Cathartes director of asset management Jackie Huber. “With a number of unique amenities, stunning water views and the downtown location, this will be a welcome destination for people looking to live in vibrant Portsmouth.”

The Maris, which translates from Latin to “of the sea,” offers views of the abutting North Mill Pond as well as the Piscataqua River and will include a full dock and a limited number of boat slips. The building features a curved, nautical-styled front and will serve as a gateway building into the city’s North End.

Residents of The Maris will have access to the building’s numerous amenities, including a fitness center with a yoga studio, bike storage, pet spa, clubroom and conference room.

The Maris will offer a mix of condominium sizes, including one, two- and three-bedroom units. All homes will have balconies with select units offering oversized terraces. Residents will have access to underground garage parking.

Once complete, the project will create more than 22,000 s/f of community space along the tidal pond. The community space will be part of the larger North Mill Pond Trail and Greenway project, offering scenic lookouts, seating areas and a multi-use path for bicyclists and pedestrians.

Sales are anticipated to begin later this year and will be brokered by The Collaborative Companies. An onsite sales gallery is scheduled to open early 2026.

“Cathartes has thoughtfully designed a residential community that celebrates its proximity to the ocean and reflects the historic feel of the surrounding community. The Maris is a one-of-a-kind opportunity for anyone looking to make Portsmouth their home, and we look forward to working with potential buyers soon,” said The Collaborative Companies vice president Laura Gollinger.

Cathartes has been involved in the city market since 2004, when it started construction on the Hilton Garden Inn and Harbour Hill Condominiums. Soon after, it led the redevelopment of the former Parade Mall into Portwalk Place and more recently, Cathartes partnered with XSS Hotels to build the AC Marriott, which abuts The Maris.

The project’s construction partner, Chinburg, has experience building communities across New Hampshire’s seacoast. Chinburg led the development of 233 Vaugh St. in Portsmouth, a luxury condominium building.