Several organizations have developed guidelines that address pediatric and neonatal intensive care. This chapter addresses some of the documents that focus on the physical environment. The majority of these organizations fully embrace the use of research to support their recommendations. It presents the summaries of guidelines and recommendations from the United States, Abu Dhabi, Australasia, Canada, China, Colombia, Dubai, India, Iran, South Africa, and the United Kingdom. The chapter explores the sources of guidelines related to sustainability in healthcare settings. The first General Standards were published in 1947 in association with the Hill-Burton program. In 1974 the title was changed to Minimum Requirements of Construction and Equipment for Hospital and Medical Facilities to reinforce the notion that the contents were minimums rather than ideal standards. The American Institute of Architects first collaborated with the US Department of Health and Human Services in the revision of the document in 1987.