A series of building rating products developed by the United States Green Building Council (USGBC) to provide a standard for what constitutes a green building or high performance building. The various LEED products are used as design guidelines & third-party certification tools, aiming ot improve occupant well-being, environmental performance & economic returns of buildings used to establish & innovative practices, standards & technologies. The collection of LEED products include LEED New Construction (NC) for newly constructed buildings, LEED Commercial Interiors (CI) for tenant build outs, LEED Existing Buildings (EB) for existing building operations & for re-certification of already certified buildings, & LEED Core & Shell (CS). An effort is also underway to develop LEED for Homes.