Miller Hull

C Concourse Expansion at SEA

SeaTac, WA
Attuning all senses to the Northwest, C Concourse becomes an extension of the region, itself.
Client Port of Seattle
Certifications Pursuing LEED Silver
Completion 2026


Traveling is often stressful. Disorienting. Long lines, delayed flights and unending layovers leave travelers exhausted and weary of airports.

C Concourse, one of the busiest crossroads at SEA epitomizes this experience; passengers waiting in line at the C2 gates interfere with arriving and departing circulation traffic, which clogs the main thoroughfare. Additionally, in the Central Terminal, there are limited dining and retail options for those seeking refreshments and a break from the congestion.

The C Concourse needed to not only be expanded, but redesigned with the passenger experience front of mind. Miller Hull and design partner Woods Bagot saw potential beyond the mere addition of airport dining and retail locations, and proposed a revised Concourse circulation path amidst a marketplace concept rooted in place-based elements from Seattle and the Pacific Northwest. Striving to do more than accommodate, this design seeks to provide a place of rest, entertainment, and delight.

The new C Concourse expansion will welcome passengers to an active, daylight-filled, two-story market that will become a destination for the frequent local travelers and a quintessential Northwest experience for all visitors.

The excitement of flight returns in this design with soaring interior volumes of space and outdoor observation decks that reconnect us to the magic of air travel and the iconic mountain and sound views that have come to define this region of the country. The folded exterior façade will address the challenging southwest-facing aperture through patterning inspired by northwest forests. Alternating south and west facing glass panels form vertical ribbons of light, each responding to the sun’s position and intensity with dynamic tinting electrochromic glass to prevent interior glare and optimize daylight. As the day progresses, the interior environment changes in direct response to the outdoor environment. On overcast, cloud-rich northwest days, visibility is maximized to celebrate the commanding views of the airfield and Olympic Range and soft, even daylight bathes the interior.

Natural materials grown and sourced in the Northwest will be used, reinforcing that this section of SEA is not only local in place, but in composition, as well.

Furthering the Port of Seattle’s commitment to a sustainable future, this project will employ a number of energy-saving strategies. The building form maximizes the building’s height, within limits set by the FAA, and defined by a photovoltaic canopy array atop the building roof that will power up to 15% of the building’s energy needs. Additionally, the facility will be combustion-free as all tenant equipment will be all-electric, eliminating the need for fossil fuels.

Freestanding kiosks are located at the center of the thriving marketplace, six of which will host a rotating series of new businesses, ensuring that there will always be something new for frequent passengers. Long-term retail and dining tenants will also occupy space in the perimeter of the marketplace, balancing the dynamic coming-and-going of nascent businesses with the reliability of permanent storefronts.

A performance stage will function as the centerpiece of this project, hosting local bands and musicians. The large central busker stage and stair termed the Grand Stair will clarify the vital role that music plays in Seattle’s culture.

With all senses attuned to this great Northwest region, the expanded C Concourse at SEA will provide an authentic and enjoyable traveling experience to tourists and locals alike.

Project Team

Architect: The Miller Hull Partnership in collaboration with Woods Bagot Architects
General Contractor/Construction Management: Turner Construction
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: Moye Consulting
Wayfinding and Signage: Mayer Reed
Lighting Design: Dark|Light
Acoustics and Vertical Transportation: The Greenbusch Group
Geotechnical Engineer: Hart Crowser
Cost Advice: Cumming
Code Compliance and Fire Protection: Jensen Hughes
Accessibility/ADA: Code Unlimited, Inc.
BIM: Autoscan
Site Investigations and Surveying: Holt Services