BEES: A Means to Measure Product Sustainability

When it comes to selecting sustainable materials, architects and interior designers are forced to make a lot of apples-and-oranges comparisons. This is because “sustainability” is an umbrella term that refers to many parameters of economic and environmental performance. Nylon Carpet Manufacturer A, for instance, promises that its production process contributes less to global warming than Manufacturer B’s, but Manufacturer B asserts that its carpet has a longer life cycle. How do you choose which product is better for the planet?

One resource available is BEES (Building for Environmental and Economic Sustainability), a free software tool developed by Barbara Lippiatt, an economist who works for the National Institute of Standards and Technology (NIST). A database of sustainability information for about 200 building products, BEES, which is now in its third edition, helps designers make difficult comparisons by measuring the materials’ life cycles over many dimensions, including economic (all costs associated with the product, from raw-material acquisition to eventual disposal) and environmental (a collection of 12 different impacts, including global warming, fossil-fuel depletion, habitat alteration, and human health).

“Since 1994, there’s been a lot of evolution of life-cycle assessment, particularly in the methods used to assess the variety of environmental impacts,” Lippiatt says. The first two iterations of BEES relied on European data. “But with the success of the earlier versions, we attracted the attention of the EPA’s Office of Research and Development, which was working on developing U.S.-specific methods. They linked up with us to make sure that [the methods] would be suitable for publication in BEES. So it’s been a nice way for them to disseminate their work to lots and lots of people, and it’s been a way for us to get a lot of credibility by having EPA-blessed methods.”

Another major change in 3.0 is the addition of brand-name materials to the list. “In the first two BEES versions, we just looked at generic products, like an industry-average brick,” Lippiatt says. “Architects and manufacturers both complained, saying, ‘We don’t buy or manufacture hypothetical averages. We want to know about the performance of real things.’

“So we launched a program called BEES Please to work directly with the manufacturers to incorporate their brand-specific products into the tool. We’re keeping the industry average ones, because it’s good to be able to benchmark a specific manufacturer against its industry average.”

BEES is relatively straightforward to use. “Say you’re considering floor covering alternatives, maybe you’re choosing between linoleum, vinyl-composition tile, or ceramic flooring,” Lippiatt says. “So you would go into BEES and look to the interior floor covering category and see the lengthy list of products available for BEES scoring, and pick just those products that you are considering for use on that particular project.”

The user then enters a couple of pieces of information, including how important environmental performance is relative to economic performance (“Maybe the customer is a real tightwad and wants a little bit of green, but isn’t willing to shell out a whole lot for it,” explains Lippiatt) and the transportation distance between where the product was manufactured and where it will be used.

BEES can assist with sustainable design’s apples-and-oranges dilemma because it includes several different weighting schemes; these schemes provide aggregate sustainability scores that can be directly compared. “You would also need to know for each decision how important all these particular environmental impacts are in respect to each other,” Lippiatt says. “That is, how important global warming is versus acid rain and so forth. That’s not something that most people would have a good sense for, so we provide a couple of default sets of weights based on studies by the experts.”

One of these default sets comes from the EPA, and the other from a Harvard study. That they differ significantly suggests the controversial nature of weighting. But, as Lippiatt points out, either set provides a good starting point for developing your own weights.

Since BEES 3.0’s release in October 2002, more than 10,000 people in 80 different countries have downloaded the program. The next version of BEES, expected in 2005, will include a much larger selection of materials. “We’ve got over 200 products in there now,” Lippiatt says, “but when you consider how many products would be under consideration for a given project, it’s just enormous.”