Architect Daniel Libeskind once said, "Architecture is not based on concrete and steel and the elements of the soil--it's based on wonder." A visit to Boston's The Hub on Causeway, a monumental mixed-use district built atop a major underground multi-modal transit station and four levels of underground parking and abutting a critical roadway artery, sparks just that: wonder.
In the case of The Hub, co-developers BXP and Delaware North and the design team of Gensler architects and LeMessurier structural engineers transformed a long-vacant site, once home to the historic Boston Garden arena, into a vibrant live-work-play environment and the new grand entrance to the TD Garden arena.
How does a design team approach such a large and complex project? "Like you did when you drafted by hand, you realize the vision one line at a time," said Todd Staples, AIA, CPHC, northeast regional realization leader for Gensler.
The 2.5-acre district comprises 1.9 million sq. ft, anchored by an eight-story structural steel podium that supports a residential tower, a hotel tower, and a 31-story steel-framed office building. The district is tied together by the podium's entertainment and retail, highlighted by The Hub, an expansive, exposed steel-framed and glass-covered entrance hall to the arena and North Station transit hub.
One of the most challenging parts of the project for the design team was the evolving nature of its components, which changed throughout the leasing process and continued through construction, requiring the design team to be nimble. When the design team started, the podium building had secured a movie theater and a much-needed grocery store for the neighborhood, but the green light to proceed with the towers above was subject to changing market dynamics and the ability to secure a hotel operator. At one point, the office tower was considered a far-off future project. Eventually, it all came together as a cohesive unit, surprisingly tied together by a single loading dock access that efficiently services the grocery, residential units, office, and entertainment venues.
The number of unknown underground conditions and existing structures at the site made constructing the foundations extremely challenging, said Ian Neill, PE, principal structural engineer with LeMessurier. At the underground garage, once excavation was completed, steel columns were erected up to the ground level and the ground-level framing was installed. The below-grade levels were then constructed while the contractor continued construction of the above-grade structure. Key components of the foundation installed between two existing subway tunnels are two huge 10-ft-deep steel plate transfer girders fabricated by Cives Steel in Augusta, Maine, and in Illinois.
Above ground, the project melds with the architectural vernacular of its surroundings, using exposed structure at the street level to evoke the traditional grit of its West End neighborhood. At the office tower's rooftop level, the design team specified architecturally exposed structural steel (AESS) for the slender round hollow structural sections (HSS) with steel casting connections that form the diagonals of a distinctive steel truss that lines the open-air deck.
From the 31st floor of its office tower to the depths of the underground garage and transit station, there is wonder to behold throughout The Hub on Causeway.
For scenes from The Hub on Causeway tour during the AIA25 Conference on Architecture & Design in June, click here.
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