The idea of energy efficient, healthy buildings has been around for a long time. So why is the concept of "sustainable building" just now entering the mainstream and catching the attention of the fortune 500's? There are probably several reasons; 1) Global Warming, 2) Rising Energy Costs, 3) Awareness and Liability Costs associated with "Sick Building Syndrome, 4)Declining Oil Reserves, 5)Concerns about our water supply, the list goes on, but whatever the reason or reasons, its time has come. Which begs the question, what is IT? My personal definition is simple. A home's design is “green” if it serves to reduce many of the harmful impacts of buildings on our environment and a home's inhabitants. Sustainable home design revolves around four key issues: 1. Designing for energy efficiency including the use of renewal energy sources such as wind, geothermal, and solar. 2. Creating a healthy indoor air environment with adequate ventilation and making material choices that minimize volatile organic compound (VOC's) outgassing within the home. 3. Providing for the efficient use of water via appliance, faucet, and shower head choices and in arid climates by zeroscaping and recycling grey water and capturing rain water for landscaping and other non-potable uses. 4. Specifying building materials and resources that are sustainable and produce a minimal amount of upstream environmental impact.