Green buildings are generally assumed to be energy efficient and sustainable. However, such indefinite concepts need to be reduced to measurable criteria to be incorporated into construction documents, contracts and building codes. Although others are being developed, the most widely used green building benchmark is currently the LEED rating system developed by the U.S. Green Building Council.
To receive LEED certification, a project must meet a variety of prerequisites such as minimum energy performance and indoor air quality requirements, and then earn points for achieving specific goals or standards in seven categories. Based on total points earned, the building is designated by USGBC as Certified, Silver, Gold or Platinum.
The current version of the LEED Rating System, LEED 2009, features a 110 point scale, allocated as follows:
• Site Selection – 26
• Water Efficiency – 10
• Energy and Atmosphere – 35
• Materials and Resources – 14
• Indoor Environmental Quality – 15
• Innovation in Design - up to 6 bonus points
• Regional Priority – up to 4 bonus points
Designations range from Certified, with a minimum score of 40, to Platinum, with a minimum score of 80. “Checklist” systems encourage designers and design-build contractors to select points enabling the building to receive the desired certification, but often lead to problems during the building’s construction or operation. The following are examples of some of the negative consequences that can result from selecting design features based solely on LEED points.