Morris Adjmi Architects

350 & 400 Summer

1,000,000 square feet
17 stories
Boston, Massachusetts

350 and 400 Summer Street are two adjacent 17-story commercial buildings located within Boston’s Seaport District. Once complete, the new structures will host a mix of state-of-the-art office and laboratory spaces, featuring extra tall floor-to-ceiling heights. Below, the carefully considered public realm is activated with a tiered public plaza called the “Summer Steps” and more than 50,000 total square feet of retail and restaurant uses.

For the design of 350 and 400 Summer Street, MA created contemporary, high-performance buildings that connect the context of the adjacent Fort Point Channel Landmark District to the revitalized Seaport, which does not have a consistent style but instead features a vast range of glassy, modern styles. Remnants of the site’s industrial waterfront setting were also referenced, including disbanded railway tracks, bridges, and other historic structures found throughout the harbor.

Three sides of each building were directly inspired by the ubiquitous 19th-century brick warehouses found throughout Fort Point to achieve this concept. Interestingly, most of Fort Point’s historic buildings were designed for a single company, the Boston Wharf Co., by two staff architects. As a result, many similarities between these buildings are apparent; most are masonry lofts with a recurring ratio of an articulated top, upper portion with small bays, and lower portion with large bays. A similar progression of bays was mirrored on 350 and 400 Summer’s three brick-clad façades. 350 Summer features textured black brick with arched-topped openings, while 400 Summer features light gray brick with rectangular openings. On each, the factory-style windows are surrounded by pre-finished extruded aluminum frames.

To create a dialogue with the Seaport’s newer buildings, 350 and 400 Summer’s facing façades are glazed curtain walls that cut into each building’s volume. These façades open the two buildings up to abundant natural light, as well as the Summer Steps—a series of tiered public plazas that runs along the entire length of the two new structures. The glass façades allow the buildings to connect to the steps both visually and through multiple openings, which tie into elongated interior lobbies that also connect Summer Street to Congress Street—two disparate and important thoroughfares separated by a 25-foot grade change.


350 and 400 Summer are expected to achieve LEED Gold certification, which will be realized through onsite rainwater management and the reduction of indoor water use, optimized energy performance, and enhanced commissioning. Further, 400 Summer will be built with a high-performance, prefabricated and unitized curtain wall system that will reduce energy consumption to a third of the national average for similar laboratory buildings.

The Summer Steps will move pedestrians in a gracious way from Summer Street down to Congress Street. In addition to providing the much-needed pedestrian connection between the two streets, the Summer Steps will serve as a vibrant activation of the public space between 350 and 400 Summer Street. Built-in amphitheater-style seating and gathering spaces will allow the steps to host a wide range of performances and community events year-round.