Let s get more specific about what we actually mean by the term green building or high-performance building. A green building is one that considers and then reduces its impact on the environment and human health. A green building uses considerably less energy and water than a conventional building, has fewer site impacts and generally higher levels of indoor air quality. It also accounts for some measure of the life-cycle impact of building materials, furniture and furnishings. These benefits result from better site development practices; design and construction choices; and the cumulative effects of operation, maintenance, removal, and possible reuse of building materials and systems.

In the United States and Canada, a green building is generally considered to be one certified by the LEED green building rating system of the U.S. Green Building Council (USGBC) or Canada Green Building Council (CaGBC). More than 99 percent of the certified green buildings in both countries come from this system. ^[*] For the purposes of this book, I will be using high-performance buildings to designate those that achieved a Gold- or Platinum-level certification from the U.S. or Canadian LEED systems. This is not entirely a fair choice, because there are some excellent green buildings that only achieved a LEED Silver status; however, increasingly, one must ask that a high-performance building achieve LEED Gold or Platinum. There might even be examples of Zero Net Energy buildings that one would consider high-performance from an energy efficiency standpoint that don t...