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 | Nov 3, 2016
OSHA proposes safety standards changes to reduce employer costs
The changes include clarification on excavation standard and reporting job-related hearing loss.
Codes and Standards | Nov 2, 2016
New resources available to reduce plug loads using advanced power strips
A tenant education program can boost efficiency in office buildings.
Codes and Standards | Oct 26, 2016
Design industry lagging in meeting AIA 2030 Commitment goals, says AIA
Only 4% of projects have met the 70% energy savings target.
Codes and Standards | Oct 25, 2016
Concerns over megaquake in Oregon provoke debate over school building standards
According to advocates, communities should consider increased resiliency.
Codes and Standards | Oct 24, 2016
Building energy codes projected to save $126 billion in energy costs from 2010-2040
Commercial and residential structures are both included in the total.
Codes and Standards | Oct 24, 2016
Fall hazards, hazard communication lead 2016 OSHA top violations
The 2016 list bears a strong resemblance to the 2015 list.
Codes and Standards | Oct 21, 2016
Green Bond Guidelines for the Real Estate Sector updated
The market growth is a signal of future opportunities.
Codes and Standards | Oct 20, 2016
What top-ranked energy efficiency states are doing right on codes, utility mandates
Calif., and Mass., use aggressive targets to lead nation.
Codes and Standards | Oct 20, 2016
New cross-laminated timber fire tests back proponents of high-rise wood structures
'Demonstrating for the first time the feasibility of tall mass timber buildings in the U.S.’
Codes and Standards | Oct 14, 2016
ASCE issues first tsunami-safe building standards
The new standards will become part of international building code.