A self-sufficient house is one that operates without need for external electricity, natural gas, sewage, or other utilities. Self-sufficient houses usually are designed to minimize heat exchange with the outdoors through proper insulation and to collect or block solar energy by passive design. In addition, self-sufficient houses collect water through wells or through rainwater collection. Some self-sufficient houses also use waste disposal systems that do not require connection to a sewage system, such as composting toilets.
An example of an effort to create affordable self-sufficient houses is the Earthship project at http://www.earthship.org.
A more complete discussion of this topic is under the heading "Autonomous building."
