SeaTac Low Voltage
SeaTac Airport Main Terminal Low Voltage Systems Upgrade / SeatacWA
What preconstruction planning is needed for updating electrical systems in one of the busiest airports in the country?

This project will update the electrical systems at Seattle-Tacoma International Airport – one of the busiest airports in the country. The project focuses on all electrical systems 600V and below throughout the main terminal building while always maintaining full operation and functionality. It is easy to see why the 42-month construction project requires a 3-year preconstruction and planning period: the main terminal building houses most of the ticket and check in counters, most of the baggage claim, all of the back of house baggage operations, TSA checkpoints, satellite underground train systems, Port of Seattle Police Department, and much of the FAA functions at the airport, it is easy to see why the 42-month construction project requires a 3-year preconstruction and planning period. Preconstruction began in August 2019 and runs through October 2022 with construction commencing November 2022 and running through March 2026. Overall, the project will modernize or replace 5 power centers, replace approximately 250 electrical breaker panels, and affect more than 300 other panels.

The project is necessary because the current electrical systems were installed during different eras, are no longer code compliant, and have exceeded their service life (some that date back to the original 1949 construction). It will also correct a number of systems that were improperly installed and resolve issues where documentation has been lost or was never present.

Mortenson was chosen under the GC/CM procurement process to work with the design engineer, Casne Engineering, to develop budgets and schedules that will meet the goals as well as provide a predictable and reliable schedule that will minimize the impact that the anticipated 1200+ panel shutdowns will have on a facility that never pauses operations.

Facts And Figures

Port of Seattle


Delivery Methods


The Team