Building for Environmental and Economic Sustainability (BEES): Software for Selecting Cost-Effective Green Building Products

摘要

Building for Environmental and Economic Sustainability (BEES) measures the environmental performance of building products using the internationally standardized and science-based life-cycle assessment approach (International Standards Organization, 1997; 1998; 2000). All stages in the life of a product are analyzed: raw material acquisition, manufacture, transportation, installation, use, and recycling and waste management. Up to ten environmental impacts are measured across these life-cycle stages: global warming, acid rain, resource depletion, indoor air quality, solid waste, eutrophication (the unwanted addition of mineral nutrients to the soil and water), ecological toxicity, human toxicity, ozone depletion, and smog. Due to its comprehensive, multi-dimensional scope, life-cycle assessment accounts for shifts of environmental problems from one life-cycle stage to another, or one environmental medium (land, air, or water) to another. The approach highlights the tradeoffs that must be made to genuinely reduce overall environmental impacts. BEES measures economic performance using similar life-cycle thinking. Economic performance is measured using the ASTM standard life-cycle cost method, which covers the costs of initial investment, replacement, operation, maintenance and repair, and disposal (American Society for Testing and Materials, 1994). The life-cycle cost method sums these costs over a fixed period of time, known as the study period. Alternative products for the same function, say floor covering, can then be compared on the basis of their life-cycle costs to determine which is the least-cost means of covering the floor over the study period. To combine environmental and economic performance into an overall performance measure, BEES uses the ASTM standard for Multiattribute Decision Analysis (American Society for Testing and Materials, 1995). The BEES user specifies the relative importance weights used to combine environmental and economic performance scores and may test the sensitivity of the overall scores to different sets of relative importance weights. Supporting data and computations are documented.