Green Building Standards Challenged by Authority on Environmental Impacts of Building Materials



Minneapolis, MN (09/26/07) - At a time when the home-buying public, architects, homebuilders, and government agencies are promoting “green” or environmentally friendly construction, a leading authority on the environmental impacts of building materials has challenged many of the assumptions and existing guidelines for so-called green construction.


In an article published in the September issue of Forest Products Journal , James Bowyer, University of Minnesota emeritus professor of bioproducts and biosystems engineering, claims that under some of the most widely used green-building certification programs, the choice of environmentally preferable materials is based largely “on personal bias, intuition, internal politics, and single attributes.”


One of Dr. Bowyer's criticisms is that only one of the major programs he studied calls for systematic analysis of the environmental impact of materials during their entire life cycles. That program is called Green Globes, developed and promoted by the Green Building Institute, and calls for the use of life-cycle assessment (LCA) in determining environmental attributes of all building materials. The National Association of Homebuilders' new green building standards for residential homes include a provision for using LCA, and within the past month, the widely relied-on LEED program has announced plans to implement LCA in its standards.


Under most other green certification programs, according to Bowyer, only wood is subjected to analysis and restrictions regarding sustainability and other environmental factors through a focus on product certification. Wood and wood alone must demonstrate responsible practice in product manufacture. The result is that a number of materials currently listed as environmentally preferable by green building organizations have demonstrably greater environmental impacts than nonfavored alternatives, Bowyer says.


With respect to certification of wood by the Forest Stewardship Council (FSC), a focus of LEED and many other green building programs, Bowyer observes that many provisions of FSC certification, including “attention to land tenure issues, observance of indigenous people's and worker's rights, and focusing on community relations, in addition to a wide range of environmental impacts linked to raw material extraction and processing is certainly an enlightened approach to materials selection.”


But he asks, “if these factors constitute essential elements in selection of an environmentally preferable building material, it is reasonable to ask why green building programs do not require compliance with similar standards for any material other than wood. As an example, growing and harvesting of bamboo is known to have all the problems often attributed to wood and also often bear the environmental burdens associated with monoculture plantations and intensive agriculture. It is curious, then, that bamboo is accepted without question by LEED and other green building programs as an environmentally preferable material.”


Bowyer also points out that though most programs encourage the use of recycled materials, such materials are not always the most environmentally friendly.


Given a choice of using steel framing that has 35 percent recycled content or wood framing members that contain no recycled content, nearly all green building programs encourage the use of the steel, Bowyer explains. However, “in this case, a choice to use steel framing based on recycled content would result in more than twice the energy consumption and more than four times the fossil fuel consumption to produce the framing members, and increased emissions to air and water in roughly the same magnitude as the differences in fuel consumption. . . . Is a product containing recycled content always an environmentally better choice? Clearly not!,” Bowyer writes.


Bowyer points out that green building programs “have grown out of a general concern for the impact of building construction and operation on the local, regional, and global environment. Thus, such programs address a broad array of topic areas, including energy efficiency; water management; building materials production, transport, use and maintenance; indoor environmental quality; and recycling, reuse and waste minimization.”


“In general the influence of green building programs is positive, as the programs are causing builders, architects, home buyers, and others to think systematically about how to improve the environmental performance of buildings,” he writes.




In addition to holding the title of professor emeritus, University of Minnesota Department of Bioproducts and Biosystems Engineering, Dr. Bowyer is president of Bowyer & Associates, Inc., a wood science and bioenergy consulting firm, and director of the Responsible Materials Program of Dovetail Partners, Inc., a Minneapolis-based nonprofit. He is an Elected Fellow of the International Academy of Wood Science, chairman of the Tropical Forest Foundation (Alexandria, Virginia), and member of the Governance Board and chairman of the Scientific Advisory Board of the Temperate Forest Foundation (Portland, Oregon).


Bowyer was founder and director of the Forest Products Management Development Institute at the University of Minnesota from 1994-2003. He served as project leader of the Minnesota Agricultural Experiment Station project “Environmental Life Cycle Assessment of Bio-based Materials and Products” from 1988 to 2003, and he also led a research team focused on global raw materials consumption and supply trends for more than 30 years.


Bowyer has published more than 230 articles dealing with wood science and technology, environmental life-cycle analysis, and environmental aspects of forestry, timber harvest, and wood use. He is also coauthor of the leading introductory wood science textbook in North America – Forest Products and Wood Science-an Introduction – now in its 5th edition.


The Forest Products Journal is a monthly journal containing mostly reviewed articles reporting on research involving forests and forest products. It is published by the Forest Products Society, an international professional membership organization with headquarters in Madison, Wis.




For more information, contact Dovetail Partners at or 612-333-0430. For more information about the Forest Products Journal, contact George Couch, via e-mail at, or phone 608-231-1361, ext 214.