USDA Sees Wood, Even From Diseased Trees, As ‘Preferred Green Building Material’

Susan Jones | September 30, 2011 | 11:06am EDT
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A hiker examines a fallen tree in Ecola State Park, Oregon, along the Lewis and Clark National Historic Trail. (Photo by Cheryl Jones)

( - A new study by the U.S. Forest Service says wood -- including that from diseased trees -- should be considered a "primary" material in green building because it is more environmentally friendly than materials such as concrete and steel.

"This study confirms what many environmental scientists have been saying for years," said Agriculture Secretary Tom Vilsack. "Wood should be a major component of American building and energy design. The use of wood provides substantial environmental benefits, provides incentives for private landowners to maintain forest land, and provides a critical source of jobs in rural America."

Vilsack has directed the USDA to take a lead role in advancing wood as a “preferred green building material.”

Forest Service Chief Tom Tidwell noted that in the Rocky Mountain region alone, "We have hundreds of thousands of dead trees killed by bark beetles that could find their way into the building supply chain for all types of buildings."

The Forest Service touts cross-laminated timber (CLT), which allows for large, solid-wood structural panels to be factory-produced from low-value wood, including small-diameter trees and insect- and disease-killed trees. Such low-value wood is "suitable for multi-story buildings that substantially exceed current height limitations on conventional wood-frame construction," the report says.

CLT is a new product in the United States, and USDA says more research is needed to establish the structural performance criteria required by building codes.

Environmental benefits

David Cleaves, a climate change adviser for the U.S. Forest Service, said trees removed in an "environmentally responsible way" allow forests to continue to "sequester carbon" through new forest growth. And wood products benefit the environment by "storing carbon long after the building has been constructed," he added.

Other environmental benefits of increased wood-use include increased energy efficiency and forest thinning, which reduces the risk of wildfires.

But the report also notes that despite the advantages of wood, “most building professionals and the public in general do not recognize the sustainability of wood and the role efficient wood utilization plays in mitigating climate change and contributing to maintaining the health and vitality of our forests.”

Therefore, “USDA and other stakeholders must overcome existing misconceptions about wood as a green building material and help lead the research and development efforts on green building materials.”

As part of that effort, Vilsack has directed the Forest Service to favor wood in new building construction; maintain its commitment to certified green building standards; examine ways to boost research and development projects using green building materials; and “actively work to identify innovative non-residential construction projects that use wood as a green building material.”

“Our country has the resources, the work force, and the innovative spirit to reintroduce wood products into all aspects of the next generation of buildings,” said Forest Service Chief Tom Tidwell. “As we move forward with restoring America’s forests, we are getting smarter and more efficient in how we use wood products as both an energy and green building source. Our progress in this area will also help maintain rural jobs.”

According to USDA, the use of forest products in the United States currently supports more than one million direct jobs, particularly in rural areas, and contributes more than $100 billion to the country's gross domestic product.

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