Leadership in Energy and Environmental Design (LEED)
Leadership in Energy and Environmental Design (LEED) is a list of standards and a certification scheme for environmentally-sustainable construction developed by the US Green Building Council (USGBC). The LEED Green Building Rating System is presently the most popular and respected guide for green building in the United States. It evaluates environmental performance from a whole-building perspective over a building's life cycle, providing a definitive standard for what constitutes a "green building."
LEED is a voluntary, market-driven rating system based on accepted energy and environmental principles. It aims to strike a balance between known effective practices and emerging concepts.
All new commercial buildings and major renovation projects (LEED-NC) are eligible to be considered as a LEED Building. These include offices, retail and service establishments, institutional buildings (schools, libraries, churches, etc), and hotel and residential buildings of four or more stories. Additionally, LEED certification can be applied to existing building operations (LEED-EB), commercial interiors projects (LEED-CI), core and shell projects (LEED-CS), homes (LEED-H), and neighborhood development (LEED-ND).
Four categories of LEED certification are available: Platinum (36 credits), Gold, (31-35 credits), Silver (27-30 credits), and Bronze (22-26 credits). To qualify under one of these four designations, buildings must satisfy all of the prerequisites and earn a certain number of credits. These credits are awarded in five major areas: Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials & Resources, and Indoor Environmental Quality, plus four checklist items reserved for any innovation above and beyond what is required by the checklist. Additionally, the US Green Building Council presents an annual award for the "Green Building of the Year" as well as "Pioneer Award."
LEED certification is obtained after submitting an application containing various materials documenting compliance with the requirements of the various credits. Recently the application process for new construction certification has been streamlined electronically, via a set of active PDFs that take over the function of printed template letters required under the traditional paper application method.
LEED has evolved since its original inception in 1998 to more accurately represent and incorporate emerging green building technologies. LEED-NC 1.0 was a pilot version. Projects under LEED-NC 1.0 helped inform the USGBC as to the nature of the requirements for such a rating system, and this knowledge was incorporated into LEED-NC 2.0. The present version of LEED for new construction is LEED-NC v2.2.
LEED forms the basis for other sustainability rating systems such as the Environmental Protection Agency's Labs21.