Seatac Concourse D Annex

Seattle, Washington

Seatac Concourse D Annex

2019 | Aviation | National Award — Excellence | National Award — Merit

Seatac Concourse D Annex


The Concourse D Annex is a 32,400-square-foot building that includes six gate waiting areas, concessions, charging stations, and restrooms. Featuring a mezzanine level of more than 7,000 square feet, this annex is the first structure seen by the travelling public, and the building’s simple shape conveys the dynamic nature of air travel while reinforcing the region’s natural beauty. Complementing the Arrivals Hall and another concourse at the airport, Concourse D Annex used space efficiently to reduce the amount of time passengers spend waiting for planes at a gate. Dynamic signage, technologically advanced systems and traditional signage applications all helped provide information to the public through the new and integrated facilities. The new facility provides passengers and employees with a healthy, sustainable environment, and for that, the Annex is expected to become North America’s first airport terminal building to achieve LEED Silver certification.

Communication Is Key for Design-Build

As one of the first traditional Design-Build contracts with the Port of Seattle, constant and transparent communications was key with all parties. One example where Design-Build benefited the project and allowed the project to maintain schedule was the redesign of the structural foundation system due to the instability of the existing soils, which were encountered while footing excavation and formwork was underway. Some of the keys to success on this project was co-location adjacent to the Port’s onsite office to review and track progress of all design and construction issues and daily communications on-site with the Port’s lead representatives ensured the teams vision aligned. The successes include a project that was delivered per the original design intent never sacrificing design for budget, one that was built with zero safety incidents, and delivered to the Port on-time.

Design-Build Team

Client/Owner: Port of Seattle
Design-Build Firm: The Walsh Group
General Contractor: The Walsh Group
Architect: HOK
Engineer: Lund Opsahl
Specialty Contractors: Sessler Inc.
Project Manager: The Walsh Group
Construction Duration: 12 Months
Project Cost: $25,749,266.00

Photo Credit: Heywood Chan, YE-H Photography