Which is the more sustainable building material - wood or steel? MYTH #3

According to certain “studies,” wood claims a smaller environmental footprint than any other major building material. However, a closer look at the facts reveals some significant inconsistencies with that claim.

This is week 3 of 4 where we will feature a myth about the sustainability of wood vs. steel. See here for past 2 myths #1 and #2.

MYTH: Wood is more sustainable than steel because wood construction products store carbon. 

REALITY: Carbon storage for construction products is temporary, only shifting impacts to future generations. 

• Carbon is sequestered in the fiber of trees, but that does not mean that wood buildings become large reservoirs of carbon that is stored indefinitely. Upon harvesting, the unused root and leaf systems immediately return their CO2 to the atmosphere by decay. For wood products, the reality is that carbon storage is also temporary and it is released back into the atmosphere at the end of the wood building’s life either by the demolition and subsequent decay of the wood or by incineration. 
• Ann Ingerson of The Wilderness Society states: “As a result of wood waste and decomposition, the carbon stored long-term in harvested wood products may be a small proportion of that originally stored in the standing trees―across the United States, approximately 1 percent may remain in products in use and 13 percent in landfills at 100 years post-harvest.”(1)

If you want to learn about the other myths, you can download the Steel Market Development Institute's Fact Sheet to learn more.

(1) Ingerson, Ann, “Carbon Storage Potential of Harvested Wood: Summary and Policy Implications,” The Wilderness Society, October 23, 2010, p. 1.

Which is the more sustainable building material - wood or steel? MYTH #2

Photo Credit: “Turning Up the Heat: Global Warming and the Degradation of Canada’s Boreal Forest”, Greenpeace Canada, March, 2008. 

According to certain “studies,” wood claims a smaller environmental footprint than any other major building material. However, a closer look at the facts reveals some significant inconsistencies with that claim.

This is week 2 of 4 where we will feature a new myth about the sustainability of wood vs. steel. See here for last week's myth #1.

MYTH: Wood is more sustainable than steel because it is a renewable building resource. 

REALITY: Being renewable is not the same as being sustainable.

• The wood industry claims that for every tree cut down, one or more new trees are planted. However, the claim does not take into account that it will take decades before those saplings mature. In the meantime, the forest is depleted of the oxygen, water storage and filtration, wildlife habitat, global cooling, and other benefits provided by the mature tree.(1)
• Trees are often harvested by clear-cutting, leaving large gaps in the forestland that also impact the plants and animal species left behind.

If you want to learn what the other myths will be, you can download the Steel Market Development Institute's Fact Sheet to learn more.

(1) “Understanding Environmental Product Declarations (EPDs) for Wood (Current Problems and Future Possibilities),” The Sierra Club Forest Certification and Green Building Team, September 24, 2013.

Which is the more sustainable building material - wood or steel? MYTH #1

According to certain “studies,” wood claims a smaller environmental footprint than any other major building material. However, a closer look at the facts reveals some significant inconsistencies with that claim.

Each week for the next 4 weeks we will feature a new myth about the sustainability of wood vs. steel.

MYTH: Studies demonstrate that wood is a more sustainable material than steel. 

REALITY: The most-cited study contained numerous incorrect assumptions about steel, and it omitted wood impacts.

• A study cited often by the wood industry was published by the Consortium for Research on Renewable Industrial Materials (CORRIM) and is based on outdated information. For example, it made incorrect assumptions about the quantity of steel needed for its comparisons.
• Wood is typically a single-use material. At the end of its life, a building’s wood frame is typically landfilled or incinerated. This returns any stored carbon dioxide back into the atmosphere as either carbon dioxide or methane, shifting greenhouse gas burdens to future generations. 
• In comparison, steel is the world’s most recycled material. Steel construction products have a recycling rate of more than 90 percent, meaning that at the end of a steel building’s life, more than 90 percent of its steel is recycled into another steel product, using significantly less energy than was necessary to create the original product. A material that can be recycled continually over centuries with no loss in quality and that lowers the burden on future generations is the very definition of sustainability!

If you just can't wait to see what the other myths will be, you can download the Steel Market Development Institute's Fact Sheet to learn more.