SEA’s Concourse C to nearly triple in size with $399 million expansion
Mar 17, 2026, 2:53 PM | Updated: 2:55 pm
As the FIFA World Cup in Seattle draws near, the Seattle-Tacoma International Airport (SEA) is wrapping up its roughly $399 million expansion project on Concourse C just in time for an influx of travelers.
The expansion project spans between the C and D Concourses, offering additional dining and retail spaces, a more than 20,000-square-foot Alaska Airlines lounge, and other amenities, the Port of Seattle announced.
“The heart of the space – Tree at C – will be an iconic destination that invites travelers to linger with seating, airfield views, music and art, or head upstairs for more elbowroom and dining and retail options. The expansion also encompasses office space for airport businesses, airlines, and the TSA,” the Port of Seattle stated.
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SEA’s Concourse C nearly tripling in size to meet passenger demand
Concourse C will nearly triple in size, increasing the existing 81,000-square-foot building into a 226,530-square-foot facility, including a “wish list of amenities.”
Airport officials have noted that the expansion will address a strong need for additional passenger space in one of the airport’s most high-traffic areas.
“This is where there was a lack,” Janet Sheerer, Capital Program Leader at Port of Seattle, told KIRO 7. “This is really intended to meet our existing passenger load today.”
The primary focus of the expansion is on improving travelers’ experiences, providing a comfortable space for passengers to enjoy before boarding a flight, whether it be dining or shopping around.
“This is a place where people can sit… they can eat. We’ll have music across the way,” Port of Seattle Capital Project Manager Adam Olson told KIRO 7. “A lot of the local musicians you see in other parts of the port will be performing there.”
Concourse C will feature a plethora of dining options from a mix of local favorites and national chains, such as Chili’s, Great State Burger, and Buffalo Wild Wings, among several others.
Other features will include art installations throughout the concourse, like multiple video walls, an art wall, and a “Lookout at C sculpture.”
New 2-story Alaska Airlines lounge at SEA to be largest in the country
A new Alaska Airlines lounge will be a part of SEA’s expanded C Concourse. The two-story, 40,000-square-foot lounge will soon become the largest lounge for any airline in the U.S., with each story measuring roughly 20,000 square feet, according to The Puget Sound Business Journal.
The new lounge will surpass the Delta One Lounge at New York’s John F. Kennedy International Airport, which is 39,000 square feet and opened in 2024.
Alaska Airlines revealed its plans for separate spaces for domestic and international travelers in the upgraded lounge.
“There’ll be two components of the lounge, one is the traditional Alaska lounge. We’re going to up-level everything, so it’s going to be really cool,” Ben Brookman, Alaska Airlines’ head of real estate, told The Puget Sound Business Journal. “But then we also need to have a space for the international traveler.”
The project is part of a 145,000-square-foot, $399 million expansion of the C Concourse at SEA. Although the expansion is slated to be finished before the World Cup in June, construction on the lounge has yet to begin.
Permit requests are expected to be filed by Alaska Airlines in July, according to the Port of Seattle, which oversees the airport.
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