within an autonomous shelter may also require sacrifices in lifestyle or social opportunities. Even the most comfortable and technologically advanced autonomous homes could require alterations of residents' behavior. Some may not welcome the extra chores. The Vails described some clients' experiences as inconvenient, irritating, isolating, or even as an unwanted full-time job. A well-designed building can reduce this issue, but usually at the expense of reduced autonomy. An autonomous house must be custom-built (or extensively retrofitted) to suit the climate and location. Passive solar techniques, alternative toilet and sewage systems, thermal massing designs, basement battery systems, efficient windowing, and the array of other design tactics require some degree of non-standard construction, added expense, ongoing experimentation and maintenance, and also have an effect on the psychology of the space. Systems This section includes some minimal descriptions of methods, to give some feel for such a building's practicality, provide indexes to further information, and give a sense of modern trends. Water There are many methods of collecting and conserving water. Use reduction is cost-effective. Greywater systems reuse drained wash water to flush toilets or to water lawns and gardens. Greywater systems can halve the water use of most residential buildings; however, they require the purchase of a sump, greywater pressurization pump, and secondary plumbing. Some builders are installing waterless urinals and even composting toilets that eliminate water usage in sewage disposal. The classic solution with minimal life-style changes is using a well. Once drilled, a well-foot requires substantial power. However, advanced well-foots can reduce power usage by twofold or more from older models. Well water can be contaminated in some areas. The Sono arsenic filter eliminates unhealthy arsenic in well water. However drilling a well is an uncertain activity, with aquifers depleted in some areas. It can also be expensive. In regions with sufficient rainfall, it is often more economical to design a building to use rainwater harvesting, with supplementary water deliveries in a drought. Rain water makes excellent soft washwater, but needs antibacterial treatment. If used for drinking, mineral supplements or mineralization is necessary. Most desert and temperate climates get at least of rain per year. This means that a typical one-story house with a greywater system can supply its year-round water needs from its roof alone. In the driest areas, it might require a cistern of . Many areas average of rain per week, and these can use a cistern