121 Seaport Boulevard is a new 17-story, 450,000-SF tower located in the heart the Seaport District. The project features 400,000-SF of Class A office space above a two-story, 50,000-SF retail podium. Tenant amenities include a private fitness center and a rooftop terrace with sweeping skyline and harbor views. 121 Seaport achieved LEED Platinum efficiency certification; the buildings elliptical design results in 15 percent energy savings by reducing direct solar exposure. A 70 inch wide pedestrian retail promenade with 15,000-SF of tree-lined open space is located at 121 Seaports base. Underneath 121 Seaport is three levels of below-grade parking with space for approximately 270 vehicles and 270 bicycles.
Skanska managed the construction of the foundations, below-grade parking structure and steel superstructure. The project incorporates a chilled beam system with elevated ceiling heights. Top-down construction was used saving over six million dollars and shaving six months off the overall construction schedule. The garage and building were constructed adjacent to and over the MBTA Silver Line tunnel, which runs through the site. The scope of work included construction of 32,000-SF of perimeter slurry wall, installation of 51 load-bearing elements, open cut and mined excavation of 45,000-CY of soil, and associated site utilities. The team successfully coordinated with the MBTA and performed thorough preconstruction surveys. Perimeter slurry walls were installed within inches of the active bus tunnel. It was mandatory that the Silver Line remain in operation throughout construction of the new building. Communication with the occupants was key, as well as monitoring old structures throughout construction for possible damage.