The United States is currently in the middle of the biggest hospital construction boom in more than 50 years. According to data from the U.S. Census Bureau, spending for construction of new hospitals and other medical facilities increased 65 percent between 2000 and 2006. New scientific and technological innovations, as well as advancements in medical practice and the organization of health care, demand a physical environment different from the hospitals of the past. This demand is being met by the increasing use of evidence-based design, which relies on a combination of scientifically proven research and the evaluation of completed projects to make design and construction decisions that improve the safety and functionality of hospital buildings.