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
| Sep 29, 2014
10 common deficiencies in aging healthcare facilities
VOA's Douglas King pinpoints the top issues that arise during healthcare facilities assessments, including missing fire/smoke dampers, out-of-place fire alarms, and poorly constructed doorways.
| Sep 29, 2014
Report finds links between office design, health and productivity
A new report from the World Green Building Council finds “overwhelming evidence” to support office design as a significant influencer of the health, wellbeing and productivity of staff.
| Sep 29, 2014
San Francisco office tower is first U.S. building to earn LEED Platinum v4 certification
One Sansome Street, San Francisco is the first building in the U.S. to achieve LEED Platinum v4 certification. The building is also only the second property worldwide to be awarded with v4 certification.
| Sep 29, 2014
Navy to begin BIM phased implementation in October
The U.S. Naval Facilities Engineering Command will begin its Building Information Management and Modeling (BIM) Phased Implementation Plan in October.
| Sep 18, 2014
GBCI to administer PEER certification for power grids and building projects
The Green Building Certification Institute (GBCI) will administer certification for the Performance Excellence in Electricity Renewal (PEER) program.
| Sep 18, 2014
Master Painter Institute approves 55 new paint products
The Master Painter Institute has issued approvals for 55 new paint products.
| Sep 18, 2014
OSHA announces new requirements for reporting deaths and severe injuries
The U.S. Department of Labor's Occupational Safety and Health Administration announced a final rule requiring employers to notify OSHA when an employee is killed on the job or suffers a work-related hospitalization, amputation, or loss of an eye.
| Sep 18, 2014
Eugene, Ore., passes ordinance to achieve steep energy consumption reductions
The Eugene, Ore., City Council recently passed an ordinance aimed at steeply reducing energy consumption and greenhouse gas emissions.
| Sep 10, 2014
Nine out of 10 New York City building plans fail energy code test
Earlier this year, New York City's Department of Buildings began auditing thousands of architectural plans for new and renovated office and residential buildings.
| Sep 10, 2014
AIA, CSI, and NIBS publish updated national CAD standard, includes new BIM module
The NCS helps architects, constructors and operators coordinate efforts by classifying electronic design data consistently and making information retrieval easier, the industry groups say.
