One Congress Building

The One Congress Building is a Contemporary skyscraper designed by Pelli Clark & Partners, with Cesar Pelli as lead architect, and built between 2019 and 2023 in Boston, MA.

One Congress Building is not the only name you might know this building by though. It is common for companies to want to attach their names to iconic buildings when they move in, or for the general public to come up with nicknames, and this one is no exception. The One Congress Building is also known, or has been known as, State Street Building, or One Congress Street Tower 2.

Its precise street address is 1 Congres Street, Boston, MA. You can also find it on the map here.

The building is part of the Bulfinch Crossing, which also includes a residential tower.

The One Congress building was built on a massive, partially demolished concrete structure that once housed a garage, which for many years divided several neighborhoods in the city. At street level, the tower’s base extends toward a public plaza and a pedestrian corridor that connects to City Hall Plaza. The lobby is bright and welcoming, softening the boundary between public and private spaces.

On the eleventh floor, a one-hectare rooftop garden provides a green oasis in the heart of the city, inviting people to work outdoors or enjoy an afternoon break beneath the trees.

At the time of its completion in 2023 the One Congress Building incorporated solutions that were quite advanced at the time, these included a MERV-15 air filtration system that captures 95% of airborne particles and provides four air changes per hour..

Pelli Clark & Partners, with Cesar Pelli as the lead architect, was the architecture firm in charge of the architectural design. But there was also one other architect involved, as far as we know. We are talking about CBT Architects.

That being said, architecture is a complex discipline involving many professionals from different fields, without whom this building would have not been possible. We will surely be leaving out a lot of names here, but here is a list of the people we do know also played their part in making the One Congress Building a reality:

• McNamara · Salvia in charge of Structural Engineering
• Tishman Construction as the Main Contractor
• HYM Investment Group as the Main Developer
• WSP Group in charge of MEP Engineering
• Gachot Studios in charge of Interior Design

The One Congress Building can be categorized as a Contemporary building.

The One Congress Building uses a framed tube-in-tube structure , with steel columns and poured concrete over metal decking slabs.

A framed tube-in-tube structure uses a central core, known as inner tube, which usually holds stairs, lifts and installations, and a perimeter of columns around it, which form the exterior tube. The interior tube is tipically more massive (often made of reinforced concrete), and the exterior tube is "lighter" (made of steel or concrete columns). Both tubes are conencted via horizontal elements which make up the floors and also transmit any horizontal froces from the facade to the core.

The facade employs a non-load bearing curtain wall system. This means the curtain wall modules are anchored to the building's structural frame at the edges of the floor slabs. The perimeter columns are set back slightly from the facade, allowing them to remain independent of the curtain wall system.

This configuration enables a completely free design of the curtain wall, unencumbered by structural elements, thus providing greater flexibility in aesthetic choices and maximizing the visual impact of the exterior.

From an aesthetic point of view, the facade features light-blue tinted reflective glass covering the curved and gently tapered surface. The continuous glass surface extends 26 meters above the roof level, creating the curved "sails" that crowns the building on both sides.