Nov 15 2007
LEED has made quite an impact in the green building world and more buildings are beginning to receive recognition for their designs. But how does LEED determine which buildings get to don the highly recognized plaque? They use a consensus-based point system that determines a building’s level of sustainability and ranks it accordingly.
LEED’s ranking system may not be an exact measure of sustainability, but it provides the structure necessary to evaluate the construction and operation of a building and its environmental impacts. The ranking system is built from six categories that are used to evaluate a design. Each category has a maximum amount of points that can be earned. Below is a description of these categories:
Site and Construction Impact: This must take into account erosion, sediment control, and other factors which will affect the surrounding environment. 14 Possible Points
Water Use: This includes the conservation of water, waste water technologies, reduced need for irrigation water and other uses of water throughout the structure and surrounding landscape. 5 Possible Points
Energy: This category is very important and includes all systems and uses of energy (such as HVAC systems) and the reduction of energy consumption. 17 Possible Points
Materials: This category refers to the use of renewable and existing materials, their impact on the environment and the reduction of material waste. 13 Possible Points
Indoor Air Quality: There is a minimum level of IAQ required in this category. Additionally, IAQ refers to reduction of harmful chemicals or fumes, ventilation systems, and other factors such as tobacco smoke. 15 Possible Points
Innovation of Design: Determined by the board, having an accredited professional on the design team can earn additional points. 5 Possible Points
A more detailed explanation of points earned can be found at the U.S. Green Building Council.
The total number of points is found by adding the points earned from each category, this number determines which level of LEED certification has been reached. Basic LEED certification requires at least 26 total points, a silver rating, 33, gold, 39 and the highest level of certification, platinum, requires at least 52 points. But this rating system applies to new construction, so what does that mean for our own homes?
As LEED grows they begin to look at residential homes and neighborhoods, but are currently in the pilot phase. LEED for homes will apply to single and multi-family homes, both market-rate and affordable housing. LEED is expected to launch this rating system nationally at the end of November, so very soon! To find out more about LEED for homes, click here.