world's largest mass timber airport opens to travelers in portland, oregon

zgf architects’ landmark project in pacific northwest

Portland International Airport (PDX) has officially opened its expanded main terminal of mass timber to travelers. Designed by ZGF Architects, the $2 billion renovation is a significant milestone for the Port of Portland, marking the largest mass timber project of its kind in the world. This expansion doubles the airport’s capacity, enabling it to accommodate up to 35 million passengers annually by 2045.

The design of the new terminal reflects the natural beauty of the Pacific Northwest. The terminal’s 9-acre mass timber roof evokes the experience of walking through a forest, with expansive views of the airfield and surrounding landscapes. The interior spaces are infused with natural light and greenery, creating an environment that resonates with the region’s unique character. ‘Everybody loves Portland International Airport,’ says Gene Sandoval, Partner at ZGF. ‘Our challenge was to double the capacity while designing an experience that passengers and employees will love as much as the original.’

image © Ema Peter Photography

nine-acre roof caps largest mass timber portland airport

The PDX Airport Main Terminal expansion in Portland stands as the largest mass timber project ever undertaken. The 3.5 million board feet of wood used in the roof, concessions, flooring, and feature walls were sourced from within a 300-mile radius of the airport. The wood includes contributions from small family-owned forests, non-profits, and tribal nations. This sustainable approach by the architects at ZGF both supports local economies and highlights Oregon’s tradition of forest product innovation. The mass timber roof, a marvel of engineering, symbolizes both the history and the future of sustainable wood design.

The decision to use mass timber for the terminal’s 9-acre roof was driven by considerations of cost, constructability, and a desire to celebrate the Pacific Northwest’s timber industry. The roof, which includes forty-nine skylights of varying shapes and sizes, filters natural light into sixty percent of the terminal. The structure, constructed from mass plywood panels, glulam beams, and timber lattice, showcases traditional weaving techniques indigenous to the region. This intricate design not only highlights the craftsmanship involved but also contributes to the terminal’s sustainability by reducing the need for steel and other materials.

image © Dror Baldinger

zgf mimics the city’s walkable neighborhoods

ZGF approached the design of its timber airport expansion with urban planning principles in mind, drawing from Portland’s walkable neighborhoods. The layout features smaller-scale architecture within the expansive space, before travelers enter to experience a clear and intuitive flow from the reconfigured ticket hall to security checkpoints and onwards to their gates. The pre-security marketplace, designed as a public space, features stadium seating and offers regional goods and dining. Post-security, the terminal continues to emphasize comfort and accessibility, with tree-lined pathways, café seating, and urban furniture that invite travelers to linger.

Designing with a focus on the passenger experience, the team aimed to reduce the stress commonly associated with air travel by creating a tranquil environment filled with natural elements. Collaborations with Terrapin Bright Green and PLACE landscape architects ensured that biophilia — the connection between humans and nature — was integrated throughout the terminal. The result is a space where passengers can relax and enjoy the journey through pathways lined with trees, cascading gardens, and over 5,000 strategically placed plants.

image © Ema Peter Photography

Supporting Local Economies and Forestry Practices

Sustainability was a key focus in the terminal’s design. By reusing much of the existing infrastructure and optimizing the use of wood, steel, and concrete, the project achieved a seventy percent reduction in embodied carbon compared to building a new terminal. The terminal’s highly efficient envelope and all-electric ground-source heat pump system contribute to a fifty percent reduction in energy use per square foot. Designed to withstand a 9.0 magnitude earthquake, the roof is supported by Y-shaped columns with seismic isolation bearings, allowing for lateral movement during a seismic event.

The wood sourcing strategy for the terminal was designed to support local economies and promote sustainable forestry practices. Nearly all of the wood for the glulam beams and lattice was sourced from forests managed to ensure strong ecological outcomes. Through direct sourcing approaches, over one million board feet of the wood can be traced back to its forest of origin, allowing the project to tell the story of the wood’s ecological impact and community benefits.

image © Ema Peter Photography

Instead of constructing an entirely new terminal, the Port of Portland and ZGF opted for a phased renovation and expansion. This approach allowed the airport to remain fully operational throughout the five-year construction period. The prefabricated wood roof, which spans the expanded lobby, check-in, and security areas, played a crucial role in minimizing disruptions. This strategy not only saved time and costs but also reduced the carbon footprint of the project.

The expansion of Portland International Airport’s main terminal is not just a response to the current demands of air travel but a forward-looking project that sets a new standard for airport design. With a second phase of the project already underway, set to be completed in early 2026, the terminal will continue to evolve, offering additional retail and dining amenities that further enhance the traveler experience.

image © Ema Peter Photography

image © Ema Peter Photography

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image © Dror Baldinger

image © Dror Baldinger

image © Ema Peter Photography

image © Ema Peter Photography

 

 

 

 

 

project info:

project title: PDX Airport Main Terminal

architect of record, interior design: ZGF | @zgfarchitects

location: Portland, Oregon

client: Port of Portland | @portofportland

completion: August 2024

photography: © Ema Peter Photography, Dror Baldinger

general contractor: Hoffman Skanska Joint Venture
pre-construction services: Turner Construction

engineering:
structural: KPFF Consulting Engineers (primary), Arup
MEP: PAE Engineers (primary), Arup
geotechnical: GRI
civil and airside planning: HNTB

consultants:
mass timber trade partner: Swinerton Mass Timber
steel trade partner: W&W AFCO Steel
mass timber fabricators / manufacturers: Zip-O-Laminators, Timberlab, Freres, Calvert
mass timber manufacturers: Calvert, Freres, Zip-O-Laminators
wood advisor: Sustainable Northwest and Sustainable Northwest Wood
lumber mills: Elk Creek Forest Products, Frank Lumber Co., Freres Lumber Co., Herbert Lumber Co., Kasters Kustom Cuts, Manke Lumber, Zip-O-Log Mills
aviation planning: ARUP USA
landscape: PLACE Landscape Architecture
biophilic design consultant: Terrapin Bright Green
sustainability consultant: ZGF (lead consultant), Arup
building envelope: Professional Roof Consultants Inc., RDH Building Sciences Inc.
air & wind analysis: RWDI Consulting Engineers & Scientists
erector: Derr & Gruenwald Construction
heavy lift / transport: Mammoet
glulam connections: Madlyn Metals Fab
Y column fabrication: Thompson Metal Fab
curtainwall: Benson
roofers: Snyder Roofing of Oregon LLC
lighting design: Fisher Marantz Stone
fire protection: Cosco Fire Protection Inc.
electrical: Oregon Electric Group
plumbing: Harder Mechanical Contractors
acoustics and public address: Arup
cost estimating: RLB
HVAC: Arctic Sheet Metal
architectural metals: McKinstry Co., LLC
expansion joints: Performance Contracting Inc.

exterior cladding:
metal panels: Morin Corp.
EIFS, ACM, or other: Custom Metal Cladding Ltd.
moisture barrier: Henry Co.
curtain wall: Benson Curtainwall, Arcadia
other cladding unique to this project: expansion joints by MM Systems, sunshades by McKinstry

roofing:
built-up roofing: Siplast
other: Seismic Isolators by Maurer SE

glazing:
glass: Carey Glass with Glas Trösch, Viracon
skylights: Deamor

interior finishes:
acoustical ceilings: Armstrong World Industries, Inc.
wood flooring: Zena Forest Products
paints, stains: Timber Pro
special interior finishes unique to this project: Interior sunshades by Levolux

lighting:
interior ambient lighting: Acuity Custom Architectural Lighting
downlights: Acuity Custom Architectural Lighting, Flos, Meteor
exterior: Musco Lighting
dimming system or other lighting controls: ETC Inc.

forests of origin / wood harvest sites:
Camp Adams Youth Camp, Camp Bishop Gray’s Harbor YMCA, Camp Namanu, Chimacum County Park, The Nature Conservatory Central Cascades Forest, Coquille Indian Tribe, Hanschu Family Forest, Hyla Woods, Joint Base Lewis McCord, Roslyn City Forest, Skokomish Indian Tribe, Willamette University Educational Forests, Yakama Nation