06/10/2026
Celebrating the Grand Reveal of the C Concourse Expansion at Seattle-Tacoma International Airport (SEA)!
Today marks an exciting milestone for Seattle-Tacoma International Airport, the Port of Seattle, and the entire project team as the C Concourse Expansion prepares to open to travelers. Designed by The Miller Hull Partnership and Woods Bagot in collaboration with the Port of Seattle as part of the Upgrade SEA program, the project reimagines the passenger experience through light-filled spaces, intuitive wayfinding, and stronger connections to the Pacific Northwest. The existing concourse is significantly expanded—from 81,000 to 229,500 square feet—with four new levels added above the original structure. Guided by the concept “Bringing In, Seeing Out,” the design creates new opportunities to gather, pause, and orient, from the Grand Stair and Tree at C to the Lookout at C, SEA’s first airside outdoor space.
The expansion also introduces new amenities, dining and retail destinations, and community-focused spaces while advancing the Port's sustainability goals through an all-electric design, rooftop solar array, and a project targeting LEED Platinum certification.
Congratulations to the Port of Seattle and everyone who helped bring this ambitious project to life. We're excited for millions of travelers to experience the next chapter of SEA.
Client: Port of Seattle
Architect: The Miller Hull Partnership and Woods Bagot
General Contractor/Construction Management: Turner I Seattle
Structural and Civil Engineer: Magnusson Klemencic Associates
Mechanical, Plumbing and Sustainability Engineers: PAE
Electrical Engineer, Smoke Control, Airfield and Logistics: Arup
Airport Dining and Retail Consultant: AirProjects
IT, Communications and Security: TLC Engineering Solutions
Wayfinding and Signage: Mayer/Reed
Lighting Design: Dark|Light
Acoustics and Vertical Transportation: The Greenbusch Group
Geotechnical Engineer: Haley & Aldrich
Cost Advice: Cu***ng
Code Compliance and Fire Protection: Jensen Hughes
Accessibility/ADA: Jensen Hughes
BIM: Autoscan
Site Investigations and Surveying: Holt Services
Photographer: Port of Seattle