Architectural theory and process typically are passed down over generations, and changes in the use of building materials such as concrete and steel have seen a slow evolution – from concrete’s use by the ancient Romans to the dominance of steel during the Industrial Revolution. Likewise, wood has seen its own progression in construction, and history has demonstrated its inherent strength in non-residential structures.
Today, advances in technology have expanded the options for wood construction. Cross-laminated timber, parallel strand lumber (PSL) and glued laminated timber (glulam) are among the products contributing to a wider range of wood-frame commercial buildings that all meet current building code standards. Engineered products such as these have made wood a viable choice for large-scale buildings such as arenas, hotels, retail venues and lobbies, which require tall walls and large open spaces with minimal intermediate supports – glulam can achieve spans as long as 100 feet and walls up to 20 feet.
Not only has wood allowed for these new and innovative uses, but it is the only major building material that grows naturally and is renewable. Additionally, since wood material is composed of approximately 50 percent carbon by dry weight, it provides a physical storage of carbon that was previously in the atmosphere as a greenhouse gas. And with growing pressure to reduce the carbon footprint of the built environment, wood has become a smart, sustainable option for multiple architects and designers.
Two examples of using wood’s benefits to an advantage are Arena Stage, a Washington, D.C., performing arts center, and two atriums in Central City, a large mixed-use project in Surrey, British Columbia. Both received significant recognition for their use of wood.
The renovation of Arena Stage at the Mead Center for American Theater was the first of its kind to use heavy timber components in Washington. The building features timber columns that support both the roof and a unique glass façade. The building encloses and showcases two significant historic structures, and the iconic roof salutes the Washington Monument. Not only was it built with innovative design and aesthetic appeal in mind, but by using wood as a key structural material, it also provided a wonderful finish, thereby saving the cost of interior finishes and also meeting environmental standards.
The use of timber columns saved environmental costs as it stored 215 tons of CO2. When measured by life-cycle assessment, wood performs substantially well in terms of embodied energy, air and water pollution, and its carbon footprint. By using 8,800 cubic feet of panel and engineered wood products, the Arena Stage offset 460 metric tons of CO2.
Financially, wood also was a practical choice. By supporting the glass and roof with the PSL columns, the team avoided the need for a separate interior design and revealed wood’s strength, versatility and aesthetically pleasing consistency.
The column base connections are ductile iron castings that were custom designed and then repeated on each column to drive down the cost.
Codes require all building systems to perform at the same level of safety, regardless of material used. As such, safety and code acceptance also was an important aspect of the design process. The design team’s code consultants were able to demonstrate to the local authorities that the use of wood was equal to or surpassed the performance of more conventional building materials.
Wood-frame construction has a proven safety and performance record for fire protection, seismic activity and wind resistance. With a broad range of applications – from light-duty repetitive framing common in small structures to the larger and heavier framing systems used to build arenas, schools and other large buildings – engineered wood products offer exceptional stability and strength.
Surrey Central City Atrium
Before the Washington, D.C., Arena Stage assignment, the architectural team worked with engineered wood products in British Columbia. In an environment where wood is being used more frequently than the United States, the Central City Atriums of Surrey became an ambitious project for the team, who wanted to incorporate the use of heavy timber. Advanced technologies supported the atrium and galleria roofs with trussed glulam structure and steel cables, and the north façade introduced the use of PSL to support glass – a concept that was later refined for the Washington project. The 1 million-square-foot retail and commercial development integrated a new university center, office tower and shopping mall – showcasing wood’s use.
In these examples, the industry has begun to take notice of wood construction’s viability for commercial buildings. The Surrey Central City Atrium and the Arena Stage in Washington, D.C., have received significant attention for their demonstration of wood’s capabilities and the introduction of wood innovation for commercial buildings in the United States. The Arena Stage was named one of the 10 best recent buildings in Washington by the Urban Land Institute and received several craftsmanship awards from the Washington Building Congress.
In North America – where forest management is strongly regulated to ensure that forests are legally harvested and managed to meet society’s long-term demand for forest products – choosing wood as a primary building material continues to be a practical, sustainable and responsible choice. It offers a myriad of benefits, including cost-effectiveness, reduced time of construction and renewability. By making sustainability and innovation top priorities, the wood products industry will continue to be a significant resource for architects and designers, as advances in technology allow wood to be taken to new heights.
Michael Heeney is a Vancouver architect and principal at Bing Thom Architects, where he has practiced for more than 20 years.