Home AEC Seattle-Tacoma International Approves $400MM C Concourse Expansion Project

Seattle-Tacoma International Approves $400MM C Concourse Expansion Project

C Concourse, Seattle-Tacoma International Airport, Seattle, Miller Hull Partnership, Woods Bagot, Magnusson Klemencic Associates, PAE, ARUP

By The Registry Staff

Seattle is set to elevate its status as a travel destination with the approval of a nearly $400 million expansion and revitalization project at the Seattle-Tacoma International Airport. The Port of Seattle’s recent greenlight for the C Concourse expansion signals a significant step forward in the transformation of this bustling transportation hub.

The Port of Seattle approved a budget of $399 million for the C Concourse expansion project, opening the door for substantial construction work to commence in the near future. This visionary endeavor aims to increase the existing 81,000-square-foot C Concourse to a structure of 226,530 square feet. The expansion will involve the addition of four new floors above the existing building, expanding into the D Concourse area, substantially increasing the hold room capacity, and introducing a range of exciting amenities for travelers.

Travelers can look forward to an array of offerings that will make their journey more comfortable and enjoyable. Among these is approximately 145,500 square feet of restaurant and retail space, an outdoor public lookout, a meditation room, and a nursing suite for traveling families. Notably, Seattle-based Alaska Airlines will feature a new 20,000-square-foot lounge reminiscent of an exclusive retreat for its members.

The C Concourse expansion project also includes provisions for new office spaces catering to airport businesses, airlines, and the Transportation Security Administration (TSA). This initiative reflects a commitment to fostering a thriving business environment within the airport.

The C Concourse expansion’s design work began in 2021, with civil and foundational construction work starting the following year. The Miller Hull Partnership, in collaboration with Woods Bagot, is responsible for the expansion’s design, while Turner Construction will lead the construction efforts.

Inspired by the natural beauty of the Pacific Northwest, the design incorporates biophilic elements to connect occupants with nature, creating a calming atmosphere. A signature wooden ceiling adds warmth and character to the space, while a central grand staircase, doubling as an open-air amphitheater, will serve as a central gathering point reminiscent of regional public markets. The tiered amphitheater will also host live music performances and provide space for dining and retail establishments, with more restaurants on an upper level.

One of the most distinctive features of the C Concourse expansion is its height, allowing unobstructed views of the airfield and the majestic Olympic Mountains from a glass-encased lookout deck. The exterior design showcases alternating south and west-facing glass panels equipped with dynamic tinting electrochromic glass, responding to the sun’s position and intensity to optimize daylight and prevent interior glare.

The project is dedicated to achieving LEED v4 Silver certification. Sustainability initiatives include the use of all-electric and fossil-fuel-free systems, a rooftop solar PV array, an advanced indoor air quality system, and the use of eco-friendly building materials to reduce embodied carbon. Local materials will be sourced whenever possible, further enhancing the project’s environmental footprint.

The project team for the C Concourse expansion project consists of Magnusson Klemencic Associates, PAE, ARUP, AirProjects, Moye Consulting, Mayer Reed, Dark|Light, The Greenbusch Group, Hart Crowser, Cumming, Jensen Hughes, Code Unlimited, Inc., Autoscan, and Holt Services.

“This is an exceptional project in terms of elevating the customer experience,” said Port of Seattle Commission President Sam Cho in a statement. “However, customer experience is not the only reason why we take on these major projects. The expanded concourse will expand opportunities for local businesses and support the financial stewardship of the airport by increasing revenue opportunities. The whole time we build with intention by focusing on sustainability and ensuring that our construction expands opportunities through the entire community.”

“The C Concourse Expansion project is key to establishing SEA’s future as a five-star airport,” said Lance Lyttle, managing director, SEA Airport. “The C Concourse Expansion will offer more of what guests need by expanding dining and retail options. The project also offers more of what our guests love about SEA, like public art, musical performances, sensory room, mothers nursing room, Interfaith Prayer and Meditation room, and great gathering spaces. This concourse will be a planespotter’s dream, with the Lookout at C providing views of the airfield and the Olympic Mountains beyond.”