Skanska Tops Out on Green Office Building in Boston

The tower, designed by CBT Architects, will feature double the traditional amount of vision glass in an elliptical, bevel-edged frame.
121 Seaport, Topping Out
121 Seaport, Topping Out

Boston–Skanska USA’s bid to build the most sustainable block in Boston moves closer toward realization with the development and construction services company’s topping out the office tower at 121 Seaport. Skanska is on track to complete the 400,000-square-foot building, located in the city’s Seaport District in 2018.

“The Seaport District is an old industrial area, close to CBD downtown. It’s on the way to be developed from something that was really on the outside, not really used, into something that is really hot, both for residential development, but also specially for commercial development,” Johan Karlstrom, CEO of Skanska AB, Stockholm-based parent company of Skanska USA, said during the company’s first quarter 2016 earnings conference call on May 12, 2016.

Reaching the top-out point at 121 Seaport, which also encompasses approximately 50,000 square feet of retail space, was no simple task. Skanska didn’t take the easy route, utilizing the unconventional up-down construction method, which calls for building the foundation and frame concurrently. Additionally, with a construction team of roughly 200 professionals, the company installed 3,400 tons of steel, put in place 63,000 fasteners and set four 76-foot-long plate girders to support the high-rise’s position above the Silver Line Tunnel. There were certain issues at one point, when excavation at the site uncovered remains of a wooden cargo ship that had succumbed to the sea in the 1800s. Skanska temporarily halted the project for an official archaeological investigation, and later resumed activity toward the topping out milestone.

Rendering of 121 Seaport
Rendering of 121 Seaport

The tower, designed by CBT Architects, will feature double the traditional amount of vision glass in an elliptical, bevel-edged frame not seen anywhere else in the area. The building will be a model of sustainability as well. “From the get-go, we set out to create a building that will stand out from the rest, and 121 Seaport is as striking as it is efficient,” Charley Leatherbee, head of Skanska’s development operations in Boston, said in a prepared statement. In line to achieve LEED Platinum status, the highest level of LEED certification, 121 Seaport will utilize a rain reclamation system for filtering and reusing rainwater, and a chilled beam mechanical system to decrease energy consumption. Ample natural light and water-efficient plumbing fixtures will also be on the building’s list of green attributes.

121 Seaport will join two existing developments to finish Skanska’s creation of Boston’s most sustainable block. 101 Seaport, which Skanska sold for nearly a half-billion dollars in 2016, is part of the trifecta. The 440,000-square-foot office building is home to Skanska and counts the North American headquarters of accounting giant PricewaterhouseCoopers as its anchor. The green block also includes Watermark Seaport, a 300,000-square-foot residential tower. All three projects help Boston maintain its high ranking on the list of the greenest cities in North America. According to the sustainable cities index produced by Arcadis, a top global design and consulting firm, Boston holds fifth place, coming in just ahead of San Francisco, the greenest city on the West Coast.