Environmental Impacts

Non-residential construction, the focus of our report, represents about 40% of the environmental burden of buildings. The environmental benefits of LEED are multifaceted and hard to generalize, so we present the topline findings here and in more detail in the body of the report:

Land Use. We estimate that between efficient location and the myriad of alternative transportation options supported by LEED, nearly 400 million vehicle miles traveled have been avoided by the occupants of LEED buildings. This grows to more than 4 billion vehicle miles by 2020.

Water. We expect water savings from LEED commercial buildings to grow to more than 7% of all non-residential water use by 2020. The equivalent of 2008 LEED water savings would fill enough 32-ounce bottles to circle the Earth 300 times.

Energy. LEED saves energy on many different levels, including energy related to operations, commuting, water treatment and the lower energy embodied within materials. In operational energy terms, LEED buildings consume approximately 25% less on average than comparable commercial buildings. By 2020, these energy savings amount to more than 1.3 million tons of coal equivalent each year, representing approximately 78 million tons of carbon dioxide (CO2) avoided emissions.

Materials and Resources. LEED has helped spur an entire industry in green building materials. Certified projects to date have specified a total of more than $10 billion of green materials, which could grow to a cumulative amount exceeding $100 billion by 2020.

Indoor Environmental Quality. We believe that indoor environmental quality is the most important contributor to the productivity attributes of LEED. We conservatively calculated that companies with employees working in LEED buildings realized annual productivity gains exceeding $170 million resulting from improved indoor environmental quality, a number that will grow to nearly $2 billion of annual productivity improvements by 2020.

Details on the methodological approach behind this study can be found in the appendix, starting on page 18.

What's Next?

Our 2009 Green Building Impact Report will include the impact of LEED buildings overseas as the growth of LEED's new construction standards shifts beyond the U.S. market, with fast-growing development in emerging economies.

Several new non-residential LEED standards have recently been released, such as those for schools and retail establishments, and the 2009 report will evaluate these impacts as well. It will also include the eco-footprint of residential construction, the built environment's largest source of environmental impacts.