Choosing made easier

Make informed decisions with help from BEES

Sustainable Space columnists Lori Brown and Greg Kallio are professors in the College of Engineering, Computer Science and Construction Management at Chico State University.

Get with the program
Are you a designer, builder or product manufacturer, or just plain interested in selecting environmentally preferred, cost-effective building products based on reliable green metrics? Perhaps you would just like to have another reason to use your computer other than to Twitter or update your Facebook pages? The National Institute of Standards and Technology (NIST) developed a program called BEES (Building for Environmental and Economic Sustainability) that implements a rational, systematic technique for selecting environmentally preferred, cost-effective building products.

Easy does it
The BEES 4.0 program is easy to download and install on any computer running Windows 95 or higher. Included on the Web site is a well-written technical manual and users guide. BEES 4.0 is programmed to help users make informed decisions about selecting building products based on a product’s environmental and economic performance and the decision maker’s values.

The program contains information for more than 230 building products grouped into four decision-making categories for comparing and selecting products for the building’s shell, substructure, interiors and equipment and furnishing. Building elements, such as roof sheathing and wall insulation are a just a couple examples. The software makes product comparisons based on user-inputted analysis parameters, which then allows decisions to be made for selecting greener products.

Weighing the options
Users start by setting Environmental versus Economic Performance Weights (percentages) based on what is most important for selecting the product being analyzed. If you want products based solely on the fact that they are environmentally friendly, the performance weight would be set to 100 percent and the economic weight set to 0 percent. If both environmental and economic performance is equally important, set the performance weights to 50 percent each.

The next group of weights is the Environmental Impact Category Weights. It allows users to weigh the relative importance for selecting or not selecting a product based on the following impacts: global warming, acidification, eutrophication (think Clear Lake), fossil-fuel depletion, indoor air quality, habitat alteration, water intake, criteria air pollutants, smog, ecological toxicity, ozone depletion and human health.

You may choose to define your own set of weights or select a built-in weight set derived from an EPA Science Advisory Board study, judgments by a BEES Stakeholder Panel, or a set of equal weights. These weights must add up to 100. For example, if the only important parameter for selecting a product is its global-warming impact, set that value to 100 and the others to 0. A discount rate for converting future building product costs to their equivalent present value is also set by the user. The higher the discount rate, the less important the future building product costs, such as repair and replacement costs.

And the results …
The last step is to select the building products you want to compare. You don’t have to be a super nerdy techno to quickly learn how to compare choices for building products. The technical manual and users guide has a great example showing the results for comparing floor coverings. With the Environmental and Economic Performance Weights set to 50 percent (equally important) and the Environmental Impact Category Weights set equally, the example compares ceramic tile with glass, linoleum, terrazzo, nylon carpet tiles and nylon carpet broadloom.

The BEES Overall Performance Results removes all the guesswork, showing that linoleum is the most sustainable and greenest building product compared to the others. BEES is a work in progress and the database of products is limited, but the selection process is based on solid data and is a great start for making informed green-building product-selection decisions. Have fun using BEES ( and don’t forget to send me a Tweet!