LEED buildings are buildings that have been rated in the Leadership in Energy and Environmental Design scale. The ratings are issued by the United States Green Building Council (USGBC). LEED buildings are assessed by a number of criteria to determine how environmentally sustainable they are. Awards are presented at various levels of recognition, based on open criteria. Within the United States there are more than 15,000 LEED buildings, with the number increasing dramatically as businesses become more concerned with establishing a reputation of environmental friendliness.
Generally, LEED buildings are thought to provide long-term savings, because they consume less energy over their lifetime. The initial costs, however, may be somewhat higher than for traditional buildings. Moreover, the certification itself is expensive to obtain, even for buildings that meet the criteria, because the sustainability goals require greater attention to detail, and because pursuing a LEED certification requires a fair amount of interaction with the USGBC.
The LEED system has been critiqued by some for its scoring procedure, and what are seen as biases or shortcomings of the system. For example, the LEED system looks primarily at end products used in construction, without looking at environmental costs further up the supply chain. The best example of this is the use of leather in furniture, which is considered an environmentally-sound choice by LEED standards because it does not offgas volatile organic compounds. Critics point out, however, that the process of creating leather uses many environmentally-harmful materials, all of which are ignored by the LEED system.
Many people have also pointed out that the LEED system seems to favor the use of fossil fuels in sustainable ways over their elimination entirely. More than half of the points used in the ranking system relate in some way to conservation, safety, and waste issues surrounding fossil fuels, while only a few relate to the use of sustainable alternatives to fossil fuels. This concern has been addressed by the USGBC, and they have made a strong, public commitment to the increased use of alternative fuels.
There are four levels of merit given to LEED buildings, based on the number of points accrued within the scoring system. The basic ranking, given to structures receiving between 40 and 49 points, is "LEED Certified." The next ranking, given to structures receiving between 50 and 59 points, is "LEED Silver." The ranking, given to structures receiving between 60 and 79 points, is "LEED Gold." The highest ranking, given to structures receiving 80 or more points, is "LEED Platinum."
Points are given to LEED buildings in seven different areas. In the Energy and Atmosphere category, 35 points are available, and 26 points are available in the Sustainable Site category. In the Indoor Environmental Quality category, 15 points are available, 14 points are available in the Materials and Resources category, and 10 points are available in the Water Efficiency category. At the lower end of the spectrum, 6 points are available in the Innovation in Design category, and 4 points are available in the Regional Priority category. Points are given on areas ranging from using low-emitting materials in painting, flooring, and adhesives, to reusing existing materials during a rebuild, to creating water-efficient landscape.