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 | Sep 12, 2018
Saltwater incursion into Miami’s aquifer may make city uninhabitable later this century
Rising sea levels likely to claim drinking water before land is under water.
Codes and Standards | Sep 11, 2018
Smart Surfaces Coalition will help cities reduce urban heat island effect
Surfaces can reflect away heat and help prevent flooding.
Codes and Standards | Sep 7, 2018
Certified Green Buildings may have an advantage in capital markets
Research supports financial case for certification.
Codes and Standards | Sep 7, 2018
NIST releases report outlining steps to bolster disaster resiliency
Offers immediate occupancy building codes and performance standards strategies.
Codes and Standards | Sep 6, 2018
Coalition of mayors around the globe pledge net-zero buildings by 2030
New construction to produce as much energy as it consumes.
Codes and Standards | Sep 5, 2018
New White Paper on Metal Panel Fire Safety Released
Has detailed information for insulation, fire safety requirements in U.S., other countries.
Codes and Standards | Aug 31, 2018
Trade war could make adaptive reuse more attractive
Higher cost of building materials could make rehab a better financial bet.
Codes and Standards | Aug 30, 2018
Metrics should guide strategy for schools seeking LEED certification
Assessing current status helps direct where improvements can have greatest impact.
Codes and Standards | Aug 29, 2018
The 2018 IAPMO solar and swimming pool codes now available
For installation and inspection of public and private swimming pools, spas, and hot tubs.
Codes and Standards | Aug 28, 2018
New York’s green roof program needs reform
Despite incentives, few owners add vegetative roofs.
