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 decomposeāreleasing carbon into the atmosphere.
When it comes to combating global climate change, the mantra of āwood is goodā may be simplistic.
Related Stories
Codes and Standards | Jul 20, 2017
Chicago rises to the top of U.S. cities in percentage of LEED or Energy Star office buildings
Certified office buildings reach 66% in windy city.
Codes and Standards | Jul 19, 2017
Economic impacts of climate change will jump over next two decades
Average annual cost to buildings and infrastructure from eastern storms to rise by $7.3 billion.
Codes and Standards | Jul 18, 2017
Energy modeling yields accuracy within 4%, says new study
Results of the study support theĀ usefulness of the practice.
Codes and Standards | Jul 13, 2017
Net Zero Energy rebranded as āZero Energyā
ILF aims to make new certification the sole standard for highest performing buildings.
Codes and Standards | Jul 13, 2017
New York City creates $10 million fund to help women- and minority-owned firms win construction contracts
The money is earmarked for up to $500,000 surety bonds per contract.
Codes and Standards | Jul 12, 2017
New International Building Code allows weather-resistive barriers above 40 feet
Danger of propagating flames now deemed negligible.
Codes and Standards | Jul 10, 2017
New mass plywood panel project moves ahead with federal grant
New material is substitute for concrete and steel in multi-story projects.
Codes and Standards | Jul 6, 2017
Trump ups ante on apprenticeships, gives private sector more room to design them
Initiative aimed at alleviating construction industry worker shortage.
Codes and Standards | Jul 6, 2017
Flawed modeling to blame for green buildings failure to live up to hype on energy efficiency
Explains energy performance gap from expected savings to actual savings.
Codes and Standards | Jul 5, 2017
Research study examines tall timber buildings worldwide
Industry group developing criteria for categorizing wide range of construction approaches to tall timber buildings.
