Template revised April 12, 2018.
COMMISSION
AGENDA MEMORANDUM
Item No.
11a
BRIEFING ITEM
Date of Meeting
April 28, 2026
DATE: April 20, 2026
TO: Stephen P. Metruck, Executive Director
FROM: Eileen Francisco, Director, Aviation Project Management Group
Keri Stephens, Director, Aviation Facilities and Capital Programs
Laurel Dunphy, Director, Aviation Operations
SUBJECT: S Concourse Evolution Program Update
EXECUTIVE SUMMARY
The S Concourse Evolution (SCE) project at Seattle-Tacoma International Airport (SEA) is part of
Upgrade SEA program. This project will extend the life of the S Concourse by upgrading
structural, seismic, and building systems to meet modern standards while enhancing customer
experience. A multi-phased construction approach, along with facilitating projects, mitigates
operational impacts by offsetting lost gate and holdroom capacity through short-term
improvements at multiple SEA locations.
The SCE Project is a critical infrastructure renewal effort at SEA, addressing the 53-year-old
facility’s seismic, structural, and code compliance needs while enhancing the passenger
experience. This project is essential to maintaining SEA’s operational efficiency and ensuring the
concourse meets current safety and service standards. The SCE project will renew this important
regional facility through two main objectives:
• Extend the useful life and bring the facility up to current code including structural and seismic
upgrades
• Re-purpose space left vacant by services relocated to the International Arrivals Facility (IAF)
and enhance the passenger experience by increasing amenities, expanding airport dining and
retail (ADR) opportunities, and elevating the level of service.
This project does not increase the number of gates or increase the overall capacity at SEA but
focuses on sustaining and enhancing existing infrastructure to meet long-term operational
demands.
COMMISSION AGENDA – Briefing Item No. 11a Page 2 of 4
Meeting Date: April 28, 2026
Template revised September 22, 2016.
PROJECT UPDATE
Scope/Schedule/Budget Status
The SCE program consists of the main project (base building) and multiple facilitating and
ancillary projects including: Gate D6 conversion, Cargo 3 area COBUS & Ground Support
Equipment (GSE) staging, Cargo 6 hardstand, Cargo 7 hardstand, and the 188
th
St duct bank
crossing.
The SCE base building is currently in design with a 90% design deliverable targeted in the 4
th
quarter of this year. There are also multiple early work packages that are in various stages of
design and permit. These packages include such items as temporary facilities, long-lead
procurement items, demolition, structure, regulated materials abatement, baggage handling
system, and civil. The early packages will allow facilitation of the start of construction at the end
of 2026.
Since the last briefing with Commission, considerable improvements have been made to the
project schedule. The current schedule reflects a 7-year and 10-month construction duration
with substantial completion in 4
th
quarter 2034. In comparison, at 30% design the project
construction duration was 9 years and 4 months with a substantial completion of 1
st
quarter
2036.
With the 60% design deliverable received in 4
th
quarter 2025, a robust cost estimating effort was
undertaken. The effort included independent cost estimates from the general contractor and a
3
rd
party estimator. After reconciliation, the budget for the program is approx. $2.5B. The $2.5B
is a marked decrease for the 30% estimate which was between $2.9B and $3.3B. The new budget
for the SCE program has now been established at $2.5B.
Program Next Steps
As the project progresses into the procurement and construction phases, there will be multiple
Commission actions required. The plan for Commission briefings and actions is based on the
number of Maximum Allowable Construction Cost (MACC) packages and the actions required to
support them. The current plan is project will have six (6) MACC packages with the first package
being brought to Commission in August of 2026, shortly followed by the second package in
September of 2026, and the third package in October of 2026. The latter three packages will
each be in 2027, 2028, and 2029.
COMMISSION AGENDA – Briefing Item No. 11a Page 3 of 4
Meeting Date: April 28, 2026
Template revised September 22, 2016.
The project will also provide program briefings throughout the duration of the project. The next
Commission request for authorization will be on May 26, 2026. This will be for (1) increase
authorized funding by $38.6M to complete all pre-construction activities for S Concourse
Evolution Program and (2) advertise and execute a construction contract for the 188
th
Street Duct
Bank Crossing.
The 188
th
St Duct bank crossing is a project that will facilitate utilities connection for the base
building. This project is currently at 90% design with anticipated construction beginning in third
quarter of 2026.
The current areas of focus for the overall program includes completion of design on multiple
packages, permitting and approvals, bid packages, and MACC packages as described above. The
intent is to break ground and start construction by the end of this year.
The project also continues to pursue Federal grant funding, monitor risks, and coordinate closely
with stakeholders on all aspects of the project.
Sustainability Status
The 30% Sustainable Design Approach (SDA) was presented to the SEAC Committee in March of
2025. Shortly after the presentation, final 30% supplemental SDA total cost of ownership (TCO)
memos were issued. Subsequently, Airport Building Department (ABD) confirmed that the SCE
project is considered an alteration + addition, an energy code memo was issued identifying
compliance pathways for achieving C406 energy efficiency measures and C411 renewable energy
requirements.
The 60% Sustainable Design Strategies (SDS) review was completed in January of 2026. Several
items were identified requiring resolution prior to the 90% submittal in quarter 4 of 2026, in
conjunction with the base building submittal.
The SCE project is pursuing the United State Green Building Council’s (USGBC) Leadership in
Energy and Environmental Design (LEED) Silver Certification (minimum) to support the Port’s
sustainability goals and initiatives. This program will complement what is being evaluated under
the SEF.
Accomplishments Over the Past Year
As mentioned above there are numerous facilitating projects associated with the SCE program.
Over the past year there has been significant progress on these projects with most of them
completing this year. These projects were developed to provide additional aircraft capacity to
offset gate closures at the S Concourse. Cargo 3 and Cargo 6 will be completed in May 2026.
Gate D6 which added a contact position in the D Concourse will be completed in Fall 2026. These
projects have also come in under budget with a total of $7.3M savings which returns to the
overall program budget.
COMMISSION AGENDA – Briefing Item No. 11a Page 4 of 4
Meeting Date: April 28, 2026
Template revised September 22, 2016.
Additionally, as outlined above, the schedule and costs have been significantly reduced between
the 30% and 60% design. This is due to the efforts of the project team and stakeholders, with
Port leadership to reduce scope to the necessities while meeting the requirements of the project;
including sizable value engineering efforts. These efforts allowed Port leadership to make a
determination for the project to proceed forward in February of this year.
ADDITIONAL BACKGROUND
The S Concourse facility at SEA was opened in 1973 and is owned and operated by the Port. The
facility depends on building systems that are well past their useful service life, and further
development of the facility has been limited by the authorities having jurisdiction, owing to
concerns stemming from current building code minimum requirements. The building systems
and materials used in the original construction, due to their age and manufacture, are difficult to
maintain. The facility also contains areas of encapsulated regulated materials, such as asbestos,
complicating maintenance, renovation, and development. Since the S Concourse was
constructed, passenger volumes and aircraft operations have increased dramatically, security
regulations have expanded, passenger level of service expectations have evolved, and airlines
and retailers have changed their marketing strategies.
ATTACHMENTS TO THIS BRIEFING
(1) Presentation slides
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS
October 28, 2025 – The Commission approved construction authorization for the Spot 99
Duct Bank installation.
May 27, 2025 – The Commission authorized an increase to funding, executed a professional
services agreement, advertisement of construction contracts and special testing and
inspection contracts, modification of a United Airlines lease and transferred scope and
budget for the A6 Widebody Remediation.
May 13, 2025 – The Commission was briefed on S Concourse Evolution and informed of an
upcoming funding request to advance design, scope additions, and construction.
May 14, 2024 – The Commission authorized to Prepare design and construction bid packages
for S Concourse facilitating project, Procure long-lead items.
October 22, 2022 – The Commission authorized to procure a Designer, GC/CM, Project
Management/Controls Support, and Commissioning Agent for SCE.
September 27, 2022 - The Commission was briefed on S Concourse Evolution and project
status.
April 13, 2021 – The Commission was briefed on SSAT Renovation Renewal PDD.
