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 22, 2019
California’s carbon reduction goals to be aided by programs to convert heating, hot water systems
Switch from propane to electricity is critical to plan.
Codes and Standards | Feb 21, 2019
Researchers develop software that can calculate potential solar energy yield at any location
Accounts for dynamic shading from trees, buildings and other structures.
Codes and Standards | Feb 20, 2019
Hospitals not making much progress in reducing their carbon footprint
Energy benchmarking survey shows flat emissions pattern over past 20 years.
Codes and Standards | Feb 15, 2019
Super Bowl stadium helps alleviate Atlanta’s flood problems
Capacity to store more than 2 million gallons of storm water on site.
Codes and Standards | Feb 14, 2019
ISO publishes first global BIM standards
Based on British standard and a publicly available standard.
Codes and Standards | Feb 12, 2019
Property technology adoption accelerates in commercial real estate industry
New business models create disintermediation.
Codes and Standards | Feb 11, 2019
Investing in downtowns pays off for cities, regions
Benefits include driving tax revenue, business activity, and smart development.
Codes and Standards | Feb 8, 2019
Oslo, Norway’s downtown goes virtually car-free
Parking spots converted to bike lanes, transit is fast and easy.
Codes and Standards | Feb 7, 2019
New North Carolina energy code has extensive lighting control requirements
Includes automatic shut offs for buildings of all sizes.
Codes and Standards | Feb 6, 2019
Solar carports can help with California’s Title 24 mandates
Can be combined with virtual net-metering software and tax-enabled financing.
