Applicability   The LEED guidelines can be applied to commercial, institutional, and high-rise residential new construction and major renovation. LEED is a system of four rating levels, platinum (52 points or greater), gold (39 points), silver (33 points), and standard (26 points) A total of 69 points are possible. The projects are judged on 5 categories: sustainable sites, water efficiency, energy and atmosphere, materials and resources, and indoor environmental quality. After meeting basic requirements, a project can earn points that determine the rating. Sustainable sites contribute 22 percent of the possible points, water efficiency, and materials and resources another 18 percent. These are categories which landscape architects contribute the most. Under the sustainable sites categories, credit is given for site selection (developing on sites that are not ecologically sensitive), urban redevelopment, brownfield development, reduced site disturbance, stormwater management, landscape and exterior design to reduce heat islands, and light pollution reduction. Water efficient landscaping and innovative wastewater technologies are under water efficiency. The materials and resources category include construction waste management, resource reuse, recycled content, local/regional materials, rapidly renewable materials, and certified wood. LEED requires that the process of design and construction be documented in order to obtain credit.