From the materials produced to construct buildings and the energy used to operate them, buildings consume vast amounts of resources. Buildings consume 72% of electricity, 40% of all energy, and are responsible for nearly half of all greenhouse gas emissions in the United States. Buildings – commercial and residential – thus offer the greatest single scope for energy savings through efficiency. High-performance buildings, which address human, environmental, economic and total societal impact, are the result of the application of the highest level design, construction, operation and maintenance principles—a paradigm change for the built environment.