Recently, Greenpeace announced a new Web site to help builders find alternatives to vinyl products [``Greenpeace uses Net,'' May 7, Page 16]. While I haven't spent much time on the site, one piece of advice I found there is to use wood windows rather than vinyl windows because ``... high-performance timber windows need minimal maintenance and potentially have a significantly longer life than PVC.'' This is probably a bit of an eyebrow-raiser to anyone who has spent many summer hours glazing or painting their wood-frame windows.
The Vinyl Institute's Vinyl by Design program (which includes the Web site www.vinylbyde sign.com) is aimed at educating building and design professionals on vinyl products, their histories, technical specifications and environmental characteristics. We point out in our continuing education course, which is part of this program, that vinyl is not perfect for all building applications. Rather, we describe it as a ``color on the palette'' of important building materials that also includes wood, brick, steel, other plastics and so on.
How does one make the right choice about the material in a product? The answer starts with another question: What are your criteria? Most serious and fair-minded con- sumers today want some kind of balance among such criteria as performance, cost and availability, safety, energy efficiency and low environmental impact.
Since all materials have environmental and energy impacts, there is a move in the building-and-design-standards world toward a ``building systems'' approach that focuses on how individual components interact within a building system and identifies options with the greatest potential for improving energy efficiency and reducing overall environmental effects.
When it comes down to selecting a material to use in a product, many experts agree that life-cycle assessment offers an effective way to measure environmental impact. Typically, LCAs identify all significant environmental impacts in the course of a product's entire life, including raw materials and energy; manufacturing, processing and formulation; distribution and transportation; use, reuse and maintenance; recycling; and waste management.
Some life-cycle studies have shown that the environmental benefits of a product with a long life can far outweigh the environmental effects of manufacturing the material in the product. For example, studies have shown that the environmental impact of manufacturing the vinyl used in a window is far outweighed by the decades of energy-saving benefits of that vinyl window.
Life-cycle studies challenge some people's preconceived notions. For example, a study conducted under the Building for Environmental and Economic Sustainability program, developed by the National Institute of Standards and Technology with funding from the Environmental Protection Agency, compared ``natural'' linoleum and vinyl composition tile flooring.
The study concluded that when life-cycle considerations were ``quantified and combined using the EPA importance weights, the net effect is environmental scores slightly favoring vinyl composition tile.''
Since the late 1980s, many LCA studies and inventories have been completed on vinyl products, at least 26 of which involved building materials. In general, these studies have found vinyl products to offer ecological benefits, particularly with respect to energy efficiency, thermal insulating value, low greenhouse gas generation and product durability and maintenance.
Not all studies find vinyl to be a clear winner. Sometimes, a study will show relatively little difference between materials. Even so, that's helpful to decision makers.
While LCAs are important tools, they are not perfect. For example, their results depend on the availability, quality and transparency of the underlying data.
The Vinyl Institute has supported the development of a model program that incorporates life-cycle data transparently so as to give decision makers better information about trade-offs among materials.
As time goes on, more organizations are recognizing the need for high-quality life-cycle data and are taking the initiative to conduct the necessary research and analysis.
Burns is president of the Vinyl Institute, a unit of the American Plastics Council, a trade group in Arlington, Va.