For years now, I’ve been singing the blues about the shortsightedness of U.S. building manufacturers. Products in our modern homes, like our automobiles, TV sets and magazines, seemed designed for rapid entropy— made to fall apart, if you will—fast, cheap, and out of control. What genius came up with the idea of putting moisture-susceptible drywall behind shower tile? Who thought it would be a good idea to roof homes with clay tiles that last for centuries over felt paper with a 20-year warranty? And how did the U.S. building industry decide that 50 years is an adequate design life span for ANY part of a home?
Ten years ago, life-cycle assessment of building products in the U.S. was spotty at best. In fact, building scientist Joe Lstiburek with Building America told me at the time that U.S. product research had “tremendous breadth, and almost no depth.”
But LCA wasn’t a new concept to other industries. Players in the aluminum market such as Alcoa began creating life-cycle reports on their products in the 1980s, to defend their brands from competitor claims (notably, plastic bottling companies). During that process, they discovered new money-and energy-saving efficiencies.
The cement industry also has been pro-active in seeking out accurate LCA information. That effort has helped them defend their product from criticism of its large CO2 emission footprint (due primarily to the energy required to produce Portland cement). LCAs have helped them make the case that the initial energy cost of cement should not be the only factor considered in evaluating its eco-friendliness.
Ten years later, more—but still a small minority of—manufacturers have embraced LCA. What they’re discovering, based on our research for this article, is that LCA studies tend to strengthen—not weaken—a product’s position in the green marketplace. Often, a product has environmental advantages that might otherwise go uncounted—such as surface durability that reduces the impacts of cleaning solvents, paints or stains.
GLOBAL WARMING IMPACT
LCA data measures many aspects of a product’s environmental impact over its expected lifespan. But side-by-side comparisons are complicated. For example, cedar siding may have a lower global warming impact than vinyl (because growing trees absorb CO2), but it has a higher ecological toxicity than at least one brand of recycled vinyl siding, presumably because the wood requires maintenance with paints and stains. Brick has a large CO2 footprint due to its initial production, but it’s expected to remain in service beyond 50 years. This BEES LCA study only looked at a 50-year span.
Source: CertainTeed LCA
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