Peter Moonen, co-leader of the Sustainability Building Coalition, a wood advocacy group based in Canada, told pros attending the West Coast Green conference in San Francisco recently that debate over preserving forests has sent the message that using wood is bad for the environment. But, he contended, “If we want to make a difference in the environment, wood has to play more of a role.”
Steel and concrete have a place in sustainable construction, too, Moonen said, but “we need to raise the bar on our thinking of what are the other things we can use.” He said that greenhouse gas, air pollution, and solid waste indexes are higher for steel and concrete in lifecycle assessments, which industry groups use for environmental impact ratings. “We must manage a building from a carbon perspective.”
The session highlighted a half-dozen residential and commercial projects built of engineered wood and drew on the coalition’s research that specifically addressed housing. Moonen, who also is sustainability coordinator with the Canadian Wood Council, provided several examples of wood efficiencies.
For instance, the world’s tallest structure made of timber, the nine-story residential Waugh Thistleton building in East London, had its wood panels manufactured off-site. It took 27 days to complete the on-site construction and it produced only a wheelbarrow full of waste, mostly drill shavings and other materials workers tracked into the building.
The cross-laminated timber of the Waugh Thistleton building, erected in 2008, is just one example of smartly engineered wood products that home builders and remodelers can employ in their projects, the wood advocate said. Although it’s only used in Europe right now, Moonen predicted that cross-laminated timber will be manufactured in North America within the next eight months.
According to manufacturers, cross-laminated timber provides an innovative building system for residential and commercial structures because its prefabricated components provide minimal assembly time at the site. In addition, there is no break in the insulation layer and no need for a moisture barrier in the walls. The system also is air tight and fire resistant. Cross-laminated timber is commonly used for external and internal walls, ceilings, and roofs.
Finger-jointed cedar for decking is another example of wood engineered to use the most precious part of the tree conservatively. The visible part for the deck is a high-quality veneer while other parts are made with a combination of materials.
“We can use the lesser value part of the tree and come up with better material,” he said. “Architects have an overabundance of wood to choose from.”
Leslie Mladinich is a San Francisco Bay Area-based freelance writer.