Designation of Environmentally Preferable Building Materials

Fundamental Change Needed Within LEED

Green building recognition programs have been developed in Europe and North America over the past 10-15 years with an objective of shifting the built environment toward a more sustainable mode. Such programs are important – certainly in concept – in focusing building designers and construction firms on more efficient use of energy and water, improvement of indoor air quality and occupant safety, development of more liveable and environmentally sustainable communities, and reduction of environmental impacts in the construction and operation of buildings.

Because green building programs have the potential to significantly influence builder and architect behaviors, it is important that these programs be free of bias and any political pressure that could compromise their ability to improve environmental performance. Those responsible for developing, managing, and implementing private green building recognition programs do, of course, have the prerogative of identifying priorities that express their goals and interests. However, as the influence of green building programs grows it is critical that guidelines and requirements of these programs be rational, realistic, comprehensive, and science-based to assure they actually achieve positive outcomes.

An example of non-scientifically based standards is provided by the leading green building program in North America – LEED (Leadership in Energy and Environmental Design). In this program, designations of environmentally preferable materials are often prescriptive and largely made without the benefit of systematic, comprehensive analysis. Moreover, despite the reality that the production of a full range of building materials, such as plastic, steel, concrete, and wood, results in significant environmental impacts, only wood is held to standards linked to extraction. The result is designation of “environmentally preferable materials” using single attributes that don’t often stand the test of rigorous assessment, that fail to require systematic consideration of environmental impacts through the product life of all materials, and that ignore fundamental aspects of sustainability.

Recently proposed changes to the LEED building materials rating system, if approved, are a step in the right direction. However, more fundamental changes are needed in systems used to identify green building materials. Without such change, LEED cannot legitimately maintain a leadership position in this arena.