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 | Jan 17, 2019
First resilience benchmarks for U.S. communities released
Provides way to evaluate current state of resilience and guidance for areas of improvement.
Codes and Standards | Jan 16, 2019
California mass timber building competition kicks off January 15
Competition will award $500,000 in grants to teams who design innovative buildings.
Codes and Standards | Jan 15, 2019
Hazard mitigation provisions in codes save lives and protect property
New NIBS study finds that adopting 2018 Intl. Codes generate $11 benefit for every $1 invested.
Codes and Standards | Jan 10, 2019
Ontario building first to achieve zero-carbon designation by Canada GBC
Geothermal heating, living wall among notable features.
Codes and Standards | Jan 9, 2019
Policymakers need to act to alleviate affordable housing crunch
Moody’s economist says costs including mortgage rates worsening situation.
Codes and Standards | Jan 8, 2019
Pittsburgh launches task force on construction industry fraud
Focus will be on wage violations.
Codes and Standards | Jan 7, 2019
Program uses low-cost sensors to monitor impact of stormwater mitigation systems
University/municipal partnership in Philadelphia aims to improve green infrastructure design.
Codes and Standards | Jan 7, 2019
Washington, D.C., to transition to 100% renewable energy by 2032
Includes measures to reduce emissions from buildings and transportation.
Codes and Standards | Jan 4, 2019
Canada’s National Building Code will include climate change obligations
New durability requirements for new buildings in the works.
Codes and Standards | Jan 4, 2019
LEED v4.1 beta registration begins in January
First releases are O+M, BD+C, and ID+C.
