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 28, 2016
Society of Landscape Architects releases guide to resilient design
The goal is to retrofit communities to better withstand extreme weather events.
Codes and Standards | Sep 26, 2016
Washington State Energy Code updates include dedicated outdoor air system requirements
The updates will change design approach to HVAC.
Codes and Standards | Sep 22, 2016
Construction firms pulling back from federal market due to new reporting rules
‘Subjective, very vague’ policies are said to create too much risk.
Codes and Standards | Sep 21, 2016
Airbnb presents legal liability for multifamily owners
How building owners can reduce risks.
Codes and Standards | Sep 21, 2016
Healthy buildings becoming a key design priority for both architects and building owners
Nationwide survey finds nearly three of four architects cite health impacts influencing design decisions
Data Centers | Sep 19, 2016
New ANSI/ASHRAE data center standard is performance-based, more flexible
The aim of the standard was to ‘not stifle innovation.’
Codes and Standards | Sep 16, 2016
Calm weather tidal flooding impacting several communities on East and Gulf Coasts
Local officials face the prospect of costly mitigation projects.
Codes and Standards | Sep 15, 2016
OSHA appoints new director for its construction directorate
The forty-year industry veteran has been a GC and business owner.
Energy | Sep 13, 2016
Oberlin College to hold conference on post-fossil fuel economy
The gathering will address climate change and new sources of energy.
Industry Research | Sep 12, 2016
Evidence linking classroom design to improved learning mounts
A study finds the impact can be as much as 25% per year.
