Cross-laminated timber, or CLT, is touted as a more sustainable option for building construction than concrete and steel. But is it really? The answer is complicated.
CLT is intended to replace concrete and steel whose production accounts for about 13% of global carbon dioxide emissions. Wood in CLT panels pulled CO2 from the atmosphere, and that carbon should remain locked up as long as the building stands.
Some forest scientists, climate modelers, and materials experts question how much of an environmental net gain results from using CLT to replace concrete and steel. Part of the concern relates to choices the lumber industry makes in forestry practices and manufacturing.
Lots of carbon gets dumped into the atmosphere when logs are transformed into CLT, they say. Sawmills and CLT plants typically burn bark, sawdust, and other wood wastes for heat, releasing carbon. Piles of branches, treetops, and smaller trees left behind after a harvest are often burned or left to decompose—releasing carbon into the atmosphere.
When it comes to combating global climate change, the mantra of “wood is good” may be simplistic.
Related Stories
Codes and Standards | Feb 5, 2019
Milwaukee board approves rezoning for Western Hemisphere’s tallest mass timber building
Mixed-use tower would rise 21 stories high.
Codes and Standards | Feb 1, 2019
Mass. governor proposes real estate transfer fee hike for climate resiliency projects
Opposed by real estate and trade groups, plan could generate $1 billion in next decade.
Codes and Standards | Jan 31, 2019
New York City will reform construction bid process
Streamlined process intended to improve efficiency, reduce hassle for bidders.
Codes and Standards | Jan 30, 2019
New AGC program aims to diversify construction workforce
More diversity needed to keep pace with demand for workers.
Codes and Standards | Jan 29, 2019
Registration now open for LEED v4.1 for New Construction and Interior Spaces
Emphasizes human health and integrative building design.
Codes and Standards | Jan 25, 2019
AEC professionals should push for net zero projects
Educate and lead clients to more sustainable choices, says LEED fellow.
Codes and Standards | Jan 24, 2019
OSHA unaffected by federal government shutdown
Agency fully funded for first nine months of 2019.
Codes and Standards | Jan 23, 2019
Hackers can easily take control of construction cranes
Potential for serious harm is real, say researchers.
Codes and Standards | Jan 22, 2019
Initiative will introduce open-source software for commercial and public building retrofits
Energy analysis tool will identify energy efficiency opportunities.
Codes and Standards | Jan 18, 2019
Texas city sues developer over changes in $1 billion mixed-use project
Revised plan eliminated 8-acre lagoon, trolley, show fountain, and reduced retail space.
