Sustainable Building Resources

Frequently Asked Questions

• Carbon
• Sustainable Forestry

• Do the carbon emissions produced by forestry activities negate the carbon storage benefits of wood and wood products?
  Carbon emissions associated with forestry activities do not exceed the amount of carbon stored in wood and wood products. Studies show that the emissions associated with wood production, transportation, and harvesting are relatively small in most cases. One such study of southeastern U.S. loblolly pine found that emissions from management and harvest activities accounted for only 1.6% of the total carbon stored in the wood products and the managed forest.

• Is using wood the best carbon mitigation pathway? Isn’t it better to let trees grow?
  Both are valid ways to store carbon but only one creates wood products for buildings—buildings that will store carbon throughout their service lives––while also replanting new trees after harvesting to continue the cycle of carbon sequestration. The United Nations Food and Agriculture Organization report, “Forestry for a Low-Carbon Future,” lists six key strategies for integrating forests and wood products into climate change strategies––items 2 and 3 are both important to a low-carbon future:

  1. Plant more trees
  2. Increase carbon density/stocks in existing forests
  3. Increase wood product carbon storage
  4. Reduce deforestation and degradation
  5. Use biomass for energy, replacing fossil fuel
  6. Use wood products in construction materials, avoiding fossil fuel emissions in manufacturing products with higher combined emissions

• Doesn’t cutting down trees to manufacture wood products reduce forests’ ability to store carbon?
  The carbon storage of wood offsets some of the temporary reductions of carbon stock in forests, which will re-grow and continue to absorb carbon from the atmosphere. Because the rate of carbon sequestration is greater during the years of young, vigorous tree growth, a cycle of harvesting and replanting maintains the forest's ability to serve as a carbon sink.

• How does wood’s carbon footprint compare to the other primary structural materials, like concrete or steel?
  Of the three primary structural materials used in construction, manufacturing lumber is the least energy intensive, at 33kg net carbon emissions per production ton, compared to 220kg for recycled steel, 265kg for concrete, and 694kg for virgin steel. Using life cycle analysis, Oregon State University researchers found that substituting wood for concrete and steel in commercial buildings cut GHG emissions by an average of 60%.

• I’ve heard wood stores carbon. How does that work?
  Wood is comprised of ~50% carbon by dry weight. That means wood in a building stores carbon that would otherwise be emitted back into the atmosphere. Wood continues to store carbon for the life of a structure, minimizing a building’s carbon footprint. When stored carbon is considered along with embodied carbon, many wood products have a negative CO²eq value when sourced from forests with stable or increasing carbon stocks.

• How is forest health and inventory tracked in the U.S.?
  Forest management is a historic practice that today is high tech. The USFS Forest Inventory and Analysis Program (FIA) is among the most robust, longest running national forest inventory and analysis systems in the world. FIA has been in continuous operation since 1930, publishing the most current information about forest health and productivity in each state every five years. It uses the latest technologies to acquire data through remote sensing and field activities in cooperation with states, industry, academia, and private landowner partners.

• What is climate smart forestry and how can I specify wood from that type of forest?
  The United Nations Food and Agriculture Organization defines climate-smart forestry as building on the concepts of sustainable forest management, with a strong focus on climate and ecosystem services. It builds on three mutually reinforcing components:

  1. Increasing carbon storage in forests and wood products, in conjunction with the provisioning of other ecosystem services
  2. Enhancing forest health and resilience through climate change adaptive forest management
  3. Using wood resources sustainably to substitute non-renewable, carbon-intensive materials

  While there’s no current system to certify ‘climate-smart’ wood products, U.S. forest carbon stocks are healthy and growing, according to the U.S. Department of Agriculture, which assesses annual forest stocks.

• How many acres of certified forests are in the U.S.?
  There are about 96 million acres of certified forests in the U.S., which is about 19% of total U.S. timberland—well above the global average of 11%. 11% of the world’s forest area, or 1 billion acres, is certified. More than 90% of the certified area is in the northern hemisphere, and almost half is in North America. The U.S. accounts for 9% of the world’s certified forestland.

• How can I ensure that wood I source is harvested sustainably?
  Architects, engineers, and other design professionals can be assured that timber is harvested sustainably through mechanisms like forest management certification, responsible fiber sourcing standards, and certification of mills, and underpinned by a robust set of state defined best management practices (BMPs) at the forest level.

  1. Forest management certification: Forest certification assesses a landowner’s forest management against a series of agreed standards related to water quality, biodiversity, wildlife, and forests with exceptional conservation value.
  2. Fiber sourcing standards: Fiber sourcing is another type of certification aimed at the mills to limit the risk of fiber coming from undesirable sources like high-conservation forests or illegally harvested forests.
  3. BMPs: Every US state has developed best management practices guidelines for water quality and other environmental concerns such as soil erosion and regeneration, some of which are codified into state forest practice regulation and while others are voluntary.

• How many seedlings do working forests plant each year as compared to the number of trees you harvest?
  The forest sector replants over 783 million seedlings per year. According to a 2021 study by the University of Washington - CINTRAFOR, 23 seedlings are planted per thousand board feet of lumber produced. The rate of replanting varies by region, species, and other factors so there’s not an exact tree for tree figure. It ranges from two to five seedlings per tree harvested.