On average, American airport terminals are 40 years old and in need of renovation—and PDX’s main terminal, which had been completed by ZGF in the 1980’s, was no different. In 2007, the Port of Portland initiated a three-year conversation with the City of Portland and the wider Portland-Vancouver, Wash., metropolitan community, resulting in a long-range master plan and vision for land use under the auspices of the airport and city. The master plan, shepherded by a 30-member Planning Advisory Group, led to the formation of PDX Next, the Port of Portland’s $2 billion program to bring Pacific Northwest-inspired architecture and local businesses, along with inclusive design and carbon footprint-reducing technology, to PDX. Comprised of four transformative projects including the expansion of Concourse E (completed in 2020), a new Concourse B (designed by ZGF and completed in 2021), a new Parking Addition and Consolidated Rental Car facility (completed 2021), and the main terminal expansion, scheduled for completion by 2025, with Phase 1 opening in August 2024.   

ZGF's design team traveled around the world, studying innovations at many airports and holding workshops with key airport leaders to better understand the direction of the future of travel and aviation design and to determine goals and aspirations for the airport’s expansion, the passenger experience, the processing, and the technology. The design was driven by four guiding principles: visionary design, the passenger experience, operational efficiencies, and sustainability. ZGF worked with the Port of Portland to choose between three potential expansion concepts, ultimately landing on the one that was most environmentally friendly, economically viable, enabled the airport to implement all the necessary improvements—and most importantly allowed PDX to renovate and expand in place.  

Sustainability was prioritized from the start of the design process. The decision to reuse much of the existing terminal, along with using wood and optimizing steel and concrete, enabled ZGF to achieve approximately 70% reduction in the overall structural embodied carbon footprint when compared with building an entirely new terminal.  

The efficiency of the expansion enabled the capacity of the main terminal to be doubled while cutting its energy use in half. A highly efficient, all-electric, open loop ground-source heat pump provides 95% of the airport’s heating and 100% of its cooling demand, allowing the terminal to reduce its operational carbon footprint as the utility grid greens over time. The decision to convert to a ground source system enables growth without the need to increase the footprint of the airport’s existing central utility plant.  

Other energy-saving details include the terminal’s high-performance facade which helps reduce peak cooling loads by up to 18%. Inside the terminal, the extensive daylighting strategy provides natural lighting to 60% of the terminal even under cloudy Oregon skies—with 7,800 LED bulbs providing the rest. Additionally, a 58% reduction in potable water usage was achieved via low-flow fixtures and well-water for non-potable use.  

As passenger loads will continue to increase, it was necessary to design a flexible infrastructure that would allow for future innovations, evolutions in sustainable design, and the future need for expansions. From Hong Kong to San Francisco, ZGF’s design team examined global precedents to develop a structural spacing strategy for the new roof and large roof-supporting columns that would give the terminal a flexible future.  

Key elements that made this possible were the use of 100 ft x 150 ft long-span structures and unobstructed floorplates. These long-span structures allow the airport the ability to successfully adjust to changing and future needs, creating column-free security checkpoints and adaptable check-in islands. The number of columns throughout the terminal was reduced from 670 to 34, further opening the space. Fabricated from 1-inch plate steel and filled with thermal grout for fireproofing, these massive Y-columns hold the 18-million-pound, 400,000-square-foot roof in place. The team was able to fine tune the grid and locate just 10 of the massive 53-foot columns within the existing terminal footprint, with the remaining 24 all outside its perimeter.  

This innovative solution left more infrastructure in place and minimized operational disruptions during construction, saving both time and money. These were also important moves to future-proof the airport, as they create more operational flexibility—and enable ticketing, security, processing, and retail concessions the room to evolve.