LEED (Leadership in Energy and Environmental Design) is the world's most popular green building grading system. LEED, which is available for almost all building types, provides a foundation for healthful, highly efficient, and cost-effective green buildings. Green building practices used to achieve certification include energy efficiency, water conservation, non-toxic materials, on-site renewable power, and more.
The four main categories of certification are Certified, Silver Certified, Gold Certified, and Platinum Certified. The higher the number, the better the rating. A LEED certified building will typically use 30% less energy than a comparable building that is not certified. It also usually creates conditions for lower emissions, uses fewer resources, has smaller impacts on the environment through reduced waste, and can be developed more quickly if new technology is adopted during construction.
Certification is granted to projects that meet specific criteria in each category defined by the standard. For example, to be gold certified you must reduce your carbon footprint by 5%, increase the amount of solar energy you generate with on-site systems such as solar panels or wind turbines by 2%, and use at least 20% recycled content in your building materials. There are other requirements too, but these are just some examples of what is expected of applicants trying to earn their silver, gold, or platinum certificates.
LEED stands for Leadership in Energy and Environmental Design, and it is the most generally used certification system for green buildings. It rates building projects on several factors to determine how sustainable they are. The more points a project earns, the more environmentally friendly it is.
There are four main categories that components can be rated on: Sustainable Sites, Water Efficiency, Air Quality, and Energy Efficiency. Each category has its own set of criteria that needs to be met for a project to earn a given number of points within that category. For example, a project can earn one point for achieving maximum water efficiency with no more than 20% of the site covered in water-permeable pavement, two points if it uses reclaimed water on-site, and three points if it includes solar panels as part of its energy efficiency strategy.
The goal is for all certified buildings to become eco-friendly over time, but since this is not always the case, buildings gain or lose points based on their performance.
New buildings must meet certain minimum requirements to be certified. However, older buildings can upgrade themselves to new standards by adding elements such as solar panels or rainwater collection systems.
The U.S. Green Building Council's (USGBC) Leadership in Energy and Environmental Design (LEED) Green Building Rating System provides a set of criteria for the ecologically sustainable design, construction, and operation of buildings and communities. The system was developed by building professionals who recognized the need for an internationally accepted rating system that would promote green buildings into law and policy across North America.
LEED was founded in 2001 by Michael B. Domek, PE, USGBC's senior vice president and chief operating officer; and David P. O'Brien, PE, USGBC's executive director. They saw a need for leadership in the built environment to drive sustainability forward and developed the first version of LEED while at the William W. Mifflin School of Business & Economics at Rutgers University. After joining USGBC full time in 2003, they worked with other leaders in the field to develop a second version of LEED that was released in 2009. Today, LEED has more than 2300 registered professionals who work in every major industry sector involved in the design and construction of green buildings. There are more than 600 certified practitioners who have achieved the LEED Accredited Professional (LEED AP) designation.
The third version of LEED, which was released in 2015, includes 51 new standards and 114 revisions to existing standards.