Wood products are better for the environment. They require less energy across their life cycle, reduce air and water pollution, and have a lighter carbon footprint.
Life Cycle:
Life cycle assessment studies consider the environmental impact of materials over their entire life cycle, from extraction or harvest of raw materials through manufacturing, transportation, installation, use, maintenance and disposal or recycling. These studies consistently show that wood is better for the environment than steel or concrete in terms of embodied energy, air and water pollution, and greenhouse gas emissions.
Carbon Footprint:
As they grow, trees absorb carbon dioxide from the atmosphere. They release the oxygen and incorporate the carbon into their wood, roots, leaves or needles, and surrounding soil. One of three things then happens:
- Trees start to decay as they get older and slowly release the stored carbon back into the atmosphere.
- The forest succumbs to wildfire, insects or disease and releases the stored carbon relatively quickly.
- Trees are harvested and manufactured into forest products, which continue to store the carbon. In the case of wood buildings, the carbon is kept out of the atmosphere for the lifetime of the structure or longer if the wood is reclaimed and manufactured into other products. Wood stores more carbon than is emitted during its harvest, production, transport and installation.
In each case, the cycle begins again as the forest regenerates and young seedlings begin absorbing carbon. Responsibly managed forests that carefully balance harvesting and replanting can maximize the amount of carbon stored over the long term.
Manufacturing wood into products requires far less energy than other materials, and most of that comes from residual biomass, such as bark and sawdust.
Reduce/Reuse/Recycle:
Designers and building professionals can reduce waste through design optimization, such as using right-sized framing members or pre-manufactured and engineered components. The forest products industry reduces waste in similar ways by optimizing sawmill operations and by using wood chips and sawdust to produce paper and composite products, or as fuel for clean bioenergy. In this way, wood producers are able to use 90 per cent of every tree harvested and brought to a mill. Wood also offers excellent opportunities for reuse and recycling. Recycling can be increased by using recovered wood and by ensuring that clean job site waste is separated and taken to a local recovery center.
Energy efficiency:
Wood buildings generally require less energy to construct and operate over time. The forest products industry is investing in research and development to increase energy efficiency through continual improvement, developing building systems that offer greater air tightness, less conductivity and more thermal mass where appropriate—including prefabricated systems that contribute to the low energy requirements of Passive House and Net Zero designs.
Occupant environment:
Many building designers choose wood for its beauty, warmth and natural attributes. Evidence suggests wood may contribute to an individual’s sense of well-being. For example, in an office or school, wood is thought to improve performance and productivity; in a hospital, it may have a positive impact on patient recovery.
Green building rating systems:
Wood can help to earn points in categories typically found in green building rating systems—including certified wood, recycled/re-used/salvaged materials, local sourcing of materials, waste minimization, indoor air quality, advanced building techniques and skills, and life cycle impacts. Light commercial, multi-family and single-family residential projects with extensive use of wood have achieved top-level certification under LEED® (Leadership in Energy and Environmental Design), LEED® for Homes, Green Globes® and other green building certification systems.
Environmental reporting:
The forest products industry is a leader in the evaluation and documentation of products based on their environmental impacts. The industry supports life cycle assessment as a way to understand and compare the true environmental cost of materials, and the increasing use of Environmental Product Declarations (EPDs) as way to communicate this information to consumers.
