Navigate Up
Sign In Section Home Port Home Contact Us

Seattle-Tacoma International Airport

Concourse D Hardstand Holdroom

Rendering of Concourse D Hardstand HoldroomRendering of Concourse D Hardstand HoldroomConceptual drawings courtesy of Walsh/HOK/Port of Seattle. Click images to enlarge.

Project Description

The Port of Seattle’s Concourse D Hardstand Holdroom project is designed to relieve current congestion for travelers waiting at crowded gates and aircraft waiting on the airfield for an open gate to deplane passengers during peak periods. The new holdroom uses space at Sea-Tac more efficiently to provide more space for passengers waiting for flights, reduces the amount of time passengers spend waiting for a plane to arrive at a gate, saves greenhouse gas emissions from idling aircraft, and saves airlines fuel.

This project will accommodate the current passenger volumes at Sea-Tac Airport with a space for six holdroom gates. The 32,500 square foot building will allow for what are called ‘hardstand operations,’ where passengers are shuttled to and from an aircraft parked away from the terminal building.

Travelers would access the facility from Concourse D, over a bridge to a two-story terminal. A sky-lighted curved roof structure will be light and airy and include a gently sloped ramp to the ground level and the departing gates. Amenities for passengers will include concessions, electric charging stations, free airport WiFi and restrooms. Passengers would walk through a gate door to a waiting shuttle which would take them to the aircraft parked away from the terminal. Arriving passengers would experience the same thing in reverse, however, going in a more direct route to the bag claim level or to a connecting flight.

Congestion Relief

Congested TerminalsRecord growth continues as Sea-Tac Airport has been one of the fastest growing large hub airports in the U.S. the past three years. In just seven years, passenger totals have increased by nearly 15 million, from 31.5 million in 2010 to 45.7 million in 2016.

With this growth, during peak periods of operation, all of Sea-Tac’s contact gates are in use – that is, where an aircraft is connect by a passenger loading bridge to the terminal.  Just in May and June of 2017:

  • An average of 550 flights per month were held waiting for a gate, affecting over 50,000 passengers
  • Aircraft are held an average of 150 hours, using over 67,000 gallons of jet fuel unnecessarily each month 
  • That fuel usage by idling aircraft would produce 7,858 tons of greenhouse gases annually.


The Holdroom project is scheduled to begin construction in September 2017 and open for use in Spring of 2018.

Funding Details​

The total cost to build the $38.4 million facility will come from the Airport Development Fund, which comes directly from fees charged to airlines. ​​