Seattle-Tacoma International Airport (SEATAC) is the Pacific Northwest’s biggest and most rapidly-expanding airport, with tens of millions of travelers passing through its doors every year. In an effort to improve passenger experience through increased amenity spaces and user-friendly navigation, and to honor the Pacific Northwest through sustainable design, the Port of Seattle has combined forces with West Coast-based architecture and planning firm Miller Hull Partnership and global architecture studio Woods Bagot to create the C Concourse Expansion at SEATAC. The project, slated for completion in 2026, will not only enhance traveler experience, but also the Port of Seattle’s vision to be the most energy efficient port in North America.
“First and foremost, we wanted to take what we have learned in designing other successful airport terminals and interlace the context of the Pacific Northwest into our concept and material selection to elicit a deep connection to place,” said Matt Ducharme, principal and West Coast Design Leader from Woods Bagot, in an email to The Registry. “As with all of our airport terminal projects, we work in close collaboration with our clients, partners, and community stakeholders to rethink [staid] approaches that make traditional airport experiences so unpleasant. Our work focuses on how our design can generate joy, comfort and wellbeing for users, ultimately shifting the paradigm of design and amenity standards. At SEA’s C Concourse Expansion, this methodology has influenced every aspect of the design and airport experience.”
This is not SEATAC’s only effort to improve passenger experience in recent years. In November 2021, the airport celebrated the completion of the N Concourse, which includes more open circulation areas and a new dining venue. This year, the airport will also celebrate the opening of the International Arrivals Facility, which will nearly double the number of international-capable gates, increase capacity for passengers and lower the minimum passenger connection time. With the C Concourse Expansion, passengers will be able to enjoy more access to concourse- and mezzanine-level amenities such as quick-service restaurants, retail, small business kiosks and a two-story open market with access to a music performance stage. Upper floors will also function as leasable office space, with airline lounge functions reserved for the top two floors.
“In addition to creating the most climate-conscious design possible, an important objective was overall clarity on how to move through the space, and we were able to achieve this by creating clear site lines to imbue a peaceful and orderly user experience,” Ducharme said. “In the center of the lower level is the market space which draws inspiration from regional public markets, and passengers are drawn to the upper level through views and the ability to look out over the entire concourse.”
Because the expansion does not largely affect the footprint of the building, the primary addition will be vertical. A focal pillar clad in locally-sourced Douglas fir stretches into an exterior ceiling envelope with sculptural geometric features like curves and fractals. Below, a grand staircase takes passengers to the mezzanine level, with a switchback stair that elevates passengers to a public outlook deck. The upper levels of the concourse provide airfield views facing the Olympic Range to the west. The Grand Stair also connects to the performance area, which includes open seating and a space for local musicians to entertain passengers.
“In addition to creating a rethought airport experience where design fosters clarity of movement, a sense of delight, and connection to the Pacific Northwest, the C Concourse Expansion will feature a thoughtfully curated public art and live entertainment program,” Ducharme said. “Like with the architectural and interior design, these features will create moments for quiet reflection and collective enjoyment.”
Though the location of the expansion is adjacent to C2 commuter gates that service regular and regional destinations, the two-story market will be open to all SEATAC passengers.
“The airside activity and choreography of planes and ground service equipment and staff around the C Concourse is amazing,” said Rich Whealan, principal and project manager from Miller Hull. “The C Concourse Expansion will give passengers an authentic market experience at the heart of this activity, with the unique opportunity to elevate and gain prospect over the airfield to witness and celebrate the adventure of air travel.”
Because one of the key elements of the project is sustainability, the team optimized the design to draw light from existing materials in the building’s shell.
“The exterior materials draw from the existing white aluminum panels that are a hallmark of [SEATAC], though will have a vertical orientation to celebrate the verticality of the [C Concourse Expansion,” Whealan said. “The featured southwest-facing aperture, we’re calling the folded facade, provides controlled daylight to all floors using dynamic electrochromic glass to protect occupants from glare and the interior spaces from overheating on sunny days, and can optimize transparency and daylight during our more frequent overcast skies.”
The project is the first to employ the Port of Seattle’s Sustainable Project Framework in its design, with the goal of making the Port of Seattle the greenest port in North America. Ducharme explained the team’s emphasis on project materials like locally-sourced Douglas fir that not only support environmental and passenger health, but also connect the design with the Pacific Northwest. Other sustainable features like fossil fuel-free systems for heating and hot water, electrochromic window glazing, low flow water features and rooftop photovoltaics help the project achieve these goals. The latter has the added benefit of grounding the project.
“The slope of the rooftop photovoltaic panel array follows a line established by the FAA that defines the highpoint of the array down to the runway, thereby grounding the C Concourse tower to its place within the context of SEA,” Whealan said.
The team looks forward to how the vertical connections of the expansion aid with passenger navigation. They also hope to see similar design features incorporated in future projects around the United States.
“The Grand Stair and its adjacent colossal pillar that serves as an emblematic focal point in the terminal’s interior are two important design elements, as is the public lookout deck, an offering that is increasingly becoming a hallmark amenity of our airport terminal designs, and something that we see as a feature that will grow in prevalence across the U.S. in time based on projects such as the SEA C Concourse Expansion,” Ducharme said.
The project is slated to begin early summer 2022 with early enabling tasks such as underground utilities and structural foundation upgrades, according to Whealan. Vertical steel rising should begin later in the spring of 2023, with project completion currently planned for the spring of 2026.