According to the Washington Post, the possibilities offered by getting more engineered wood into the construction industry is enticing builders and dividing environmentalists. Research at the University of Massachusetts at Amherst is proving that engineered wood - in this cases 20 boards of eastern hemlock glued together in perpendicular layers, can withstand twenty-one thousand pounds of pressure before cracking. Referred to as "cross-laminated timber and “mass timber,” the material appeals to builders, city planners, architects and environmentalists, but not all of them.
Builders see it as a way to construct midrise structures faster and cheaper. City planners see a fast track that could help reduce housing shortages. Architects love its light weight and look. And some environmentalists tout its ability to lock up carbon to combat climate change. “We call it a win, win, win, win,” explains Robert Perschel of the New England Forestry Foundation.
Advocates envision a radical shift in construction, with wood buildings of seven to 18 stories sprouting wholesale in cities, drastically reducing the cement and steel that generate tons of greenhouse gases. The perceived environmental benefit is key to their enthusiasm, moving discussion of mass timber out of builders’ trade shows and into academic and governmental offices. By utilizing wood, proponents argue, the carbon stored in it during tree growth is retained within floors and walls.
“It’s kind of amazing,” said Nicole St. Clair Knobloch, a climate policy expert who has a U.S. Forest Service grant to promote mass timber in Massachusetts. “That carbon, you put it in a building, it’s going to stay in the building. It’s not going to be released to the atmosphere.”
Not all environmentalists are on board, though. The Sierra Club contends that nearly two-thirds of trees’ carbon is lost to the atmosphere when forests are cut and milled, and replanting young trees does not always offset that loss.
Read More
