Seattle-Tacoma International Airport (SEA) is moving ahead with a 2.5 billion USD renovation of its S Concourse, with major construction scheduled to begin in 2027.
The Port of Seattle Commission approved 1.1 billion USD in initial funding on 11 August for the S Concourse Evolution (SCE) project. The wider renovation is part of the airport’s 5.5 billion USD Upgrade SEA capital improvement programme.
The S Concourse dates from 1973 and primarily serves international passengers. The project will upgrade its structural, seismic and building systems while providing additional passenger facilities and improving aircraft operations.
The renovation will add approximately 150,000 square feet of space, including a new upper concourse level. Selected gates will receive improved dual-level boarding facilities, while dining, retail, lounge and other passenger amenities will also be expanded.
The project will not add gates to the concourse because there is insufficient space between the main terminal and airfield. Instead, part of the customs area vacated following the opening of SEA’s International Arrivals Facility in 2022 will be repurposed.
The S Concourse Evolution project is expected to take around eight years to complete, with the work divided into multiple phases to allow flight operations to continue during construction.
A temporary S Annex will be constructed to the east of the existing concourse to support ground boarding operations while gates are affected.
The Port of Seattle expects a maximum of three of the concourse’s 12 gates to be affected by construction at any one time. Areas will reopen to passengers as individual phases are completed, with the overall project currently expected to finish in 2034.
Port of Seattle Commission President Ryan Calkins said:Today’s authorisation to move forward with the S Concourse Evolution builds on the generational investments we are making at SEA to improve the passenger experience. The project will add critical seismic, structural, and building systems upgrades to improve long-term passenger circulation as well as operational efficiency.
AECOM is providing design services for the project. Its design incorporates local and Indigenous influences alongside upgrades to the existing structure and building systems.
The project is targeting LEED Silver certification and is expected to reduce annual operational greenhouse gas emissions by 58% compared with Port of Seattle standards. Annual energy use is projected to fall by 16%.
Planned measures include a higher-performance exterior enclosure and glazing, upgraded lighting and building management systems, and electrical equipment designed to reduce reliance on fossil fuels.
The project will also include low-flow plumbing fixtures, electric vehicle charging for aircraft service equipment and the reuse of building materials.
The S Concourse renovation follows several completed projects under the Upgrade SEA programme, including the N Concourse Modernization in 2021, the International Arrivals Facility in 2022, restroom renovations in 2025, and the SEA Gateway and C Concourse Expansion projects in 2026.
Roadway improvements are nearing completion, while baggage optimisation and replacement of the SEA Underground Controls remain under construction.
