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Upgrade SEA Spotlights C Concourse Expansion

September 25, 2023

By Aly Lande, Capital Project Marketing Specialist

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It’s been a busy year as Upgrade SEA surges forward to bring more of what travelers know and love to Seattle-Tacoma International Airport (SEA). SEA’s project teams have made substantial progress since the start of the year, including completing a few notable projects. The Upgrade SEA suite of capital projects improves all aspects of your passenger journey and with a busy rest of the year ahead, we’re continuing to bring you more news about project progress, impacts, and how the work is going to improve your airport experience.

This update on projects in progress, accomplishments, and what’s still in the queue will help make your next trip predictable and stress-free. This includes exciting things, specifically on one of our mega-projects, C Concourse Expansion.

C Concourse Expansion hits milestone and moves to major construction

C Concourse Expansion exterior building rendering

The C Concourse Expansion continues to prep for major construction to begin in 2024. This project is adding four additional floors to the existing three-story building, literally raising the roof. SEA Airport is one of the most space-constrained airports in the United States compared to the number of passengers we serve annually. The limited footprint means our project teams must get creative, in this case building up and within the current footprint. 

The expanded C Concourse will bring multi-level dining, retail, and grand seating centered around a courtyard area, Tree at C, as well as a marketplace area called the Marketplace at C. It will also have upgraded services and amenities such as an Interfaith Prayer and Meditation Room, sensory room, nursing room, and a light-filled space overlooking the airfield, aptly referred to as Lookout at C. 

New renderings from the design team of The Miller Hull Partnership and Woods Bagot, available in our public photo gallery, provide a closer look at the big and bright interior spaces centering around the Tree at C.  

The C Concourse expansion is SEA’s first project to apply the Sustainable Evaluation Framework (SEF) and has a goal of achieving LEED v4 Silver certification. Building features include a rooftop solar PV array, reduced embodied carbon and healthy materials, and all electric utilities. Cutting-edge electrochromic glazing on the glass curtain wall panels for the west-facing glass wall actively tints to help with efficiency, glare and heat. Biophilic design elements help connect occupants to nature, bringing the outside in.

The project team goes to the Port of Seattle Commission Tuesday, Sept. 26 to secure the final project budget. If approved, major construction would kick off early 2024. 

  • Follow @FlySEA for updates on the C Concourse Expansion.

PortGen event showcases C Concourse Expansion project

PortGen networking event photo

The Diversity in Contracting team and Turner Construction hosted an informational and networking event on Tuesday, Sept. 19, to encourage contracting opportunities for the C Concourse Expansion. Turner Construction is the General Contractor and Construction Manager on the project and has lots of available partnering opportunities. Some of the subcontractors that attended the event included:

  • Acoustical Design, Inc.
  • Crown Corr, Inc..
  • Cascade Construction
  • Northshore Exteriors, Inc.
  • Performance Contracting, Inc.
  • Snyder Roofing
  • Apollo Mechanical
  • Aluminum & Bronze Fabricators
  • Apex Steel

Stay up to date on contracting and bid opportunities at:
Trainings and PortGens 
Diversity in Contracting
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Upgrade SEA project updates

There are several projects with major construction happening that can impact your journey to the airport in the next few months, curb to gate. Here’s a quick update on projects currently underway at SEA!

Airport access upgrades

Curbside Accessibility and Safety
This project has completed its major work to install bollards along the Upper Departures Drive, Lower Arrivals Drive, Skybridge entrances on the Parking Garage side, and along the courtesy vehicle plaza. The installation of new ADA load/unload zones and a zero-grade curb on the Lower Arrivals Drive has also wrapped up.

Automated Parking Guidance System
Levels 1-7 are active with the new Park Assist system providing live counts for available parking stalls and red/green LED lights indicating if a stall is vacant or occupied. Level 8 and the overheight lot are still awaiting completion. Since there is no roof on Level 8, cameras will pick up when a stall is vacant or filled and provide that count to appropriate displays. These two areas are expected to be active by the end of this year.

Roadway improvements
While there won’t be any major construction impacts this year, you will start to see construction on the Southbound Airport Expressway with equipment and materials off to the side. Please drive carefully and be aware of crews working in the area.

Ticketing and Checkpoint Upgrades

SEA Gateway Project
See the vision for the new spaces in this virtual flythrough for the SEA Gateway Project.

Work began earlier this year on building out the promenade level from undeveloped space to add room for Alaska Airline’s ticketing and check-in bag drop process, and create new office space. The Alaska Ticketing Lobby is also getting reconfigured to improve the check in process and create a better flow for Alaska passengers. Barricades have been erected to help give the Alaska Ticketing Lobby a makeover.

And while picking up bags on the Baggage Claim Level, be sure to check out the new artwork near Bag Claim 5 from students in the Highline School District.

Checkpoint 1 Relocation
The Checkpoint 1 Relocation project also kicked off this year with minimal impacts to guests. Bag Claim 1 was removed to make way for the new security checkpoint. Barricades are blocking off the area for your safety and will move to a new location for more prep work in the coming months.

Post security upgrades

SEA Underground Controls Replacement
The SEA Underground’s controls system needs an overhaul, so this project will replace the Automatic Train Control (ATC) system. Work started earlier this year with a few overnight closures to do some electrical and fiber installation work, which in-turn required over-the-ramp busing. Next year the project team will get started on replacing the ATC system software and hardware which will require several overnight closures of the SEA Underground and travelers will be transported via buses. More information to come on this project and impacts later this year.

Concourse A Building Expansion for Lounges
This year has been preparation to build out a new section on the A Concourse to make way for a brand new Delta Sky Club lounge. After this gets built out the project will begin to expand the current Club at SEA Lounge as well.

Baggage Optimization
Phase 2 is still currently in construction replacing sections of the baggage handling system. Phase 3 is set to kick off in late 2024.

Concourse Upgrades

C Concourse Expansion
Early work has been progressing this year to get ready for major construction in early 2024. Micropiles have been placed to support the weight of the additional four floors going in. See more highlights and information on this exciting project in previous section.

Restroom Renovation
This project continues to add or update restrooms on the B, C, and D Concourses. This summer, a new multi-user, all-gender restroom was added on the D Concourse. Still to come this year will be renovated men’s and women’s restrooms on the C Concourse near C3 that will include a water refill station. The restroom at the end of the C Concourse near C16 will shut down while it undergoes a major renovation.

S Concourse Evolution
Still in its early planning phase, but Hensel Phelps was recently selected as the General Contractor/Construction Manager for this project.

Want to stay up to date on the latest construction impacts at the airport? Sign up for SEA Airport text alerts! Text UPDATE to 27829 for airport news, operations updates, and traveler promotions. Text STOP to end, HELP for help. Message and data rates may apply. Go to the Terms and Conditions page for privacy and terms.

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