More than 1 billion square feet of commercial real estate have been certified under the Leadership in Energy and Environmental Design (LEED) program, the U.S. Green Building Council announced last week. Since LEED’s inception in 2000, more than 36,000 commercial projects and 38,000 single-family homes have participated in the program, which acts as a benchmark for the design, construction and operation of high-performance green buildings. The U.S. Green Building Council, which is based in Washington, D.C., comprises 78 local affiliates, more than 20,000 member companies and organizations and about 131,000 LEED Accredited Professionals.