Point-Based Standard Optimization with Life Cycle Assessment for Process Design

There has been a proliferation of building and product sustainability standards based on the success of the LEEDTM program from the Green Building Council for new commercial building construction. These standards have several common features. 1) They are point-based, in which points are earned for undertaking various activities or using certain materials. 2) The points are aggregated to achieve an overall score. 3) The score is compared to a threshold that determines the rating of a building or a product. The question is whether the standards actually promote products that are better from a life cycle perspective, or whether they are biased towards certain activities based on a perception that they are inherently better than others (recycling or bio-based materials for example). In this work we use optimization methods coupled with life cycle inventory information to explore this question. A carpet standard is used to compare the life cycle optimization against an optimization to earn the maximum number of points in the standard. Our work is extended to show how sustainability assessment standards can be redesigned to make them congruent with life cycle measures so that there is less opportunity for distortions in product design to maximize performance against the standard and have a less than optimal life cycle impact.