SEA Airport Temporary Holdroom Annex Design Study

Seattle-Tacoma International Airport (SEA) needed to maintain passenger operations during the comprehensive, phased construction of the South Concourse Evolution program, an effort aimed at substantial modernization of the seven-level, 350,000-square-foot facility. The planned renovations would significantly impact gate availability, requiring the team to evaluate and analyze a temporary solution that supports domestic and international operations without disrupting airport efficiency or the passenger experience. The facility also needed to be delivered on an accelerated schedule and function reliably throughout construction.

GFT led a design study and planning effort to evaluate a temporary holdroom facility at the Air Cargo 7 apron as a potential strategy to offset operational impacts from the South Concourse Evolution project. This enabling initiative examined a 28,000-square-foot facility that supports four bus-served operational gates and accommodates domestic arrivals and departures, as well as international departures. The study explored how the design could integrate the holdroom’s restrooms, back-of-house functions, airport dining and retail spaces, and ramp operations offices into a compact, efficient layout.

To support the new facility, the project analysis evaluates the conversion of the existing cargo apron into multiple aircraft positions, including narrow-body, wide-body, and overnight parking, while identifying utility and infrastructure improvements required for sustained operations. The Pacific Northwest-inspired facility concept was designed for a minimum 10-year service life, balancing temporary construction with long-term durability, flexibility, and operational resilience. The team assessed fast-track delivery strategies and phasing scenarios to support airport operations.