Autonomous building
An autonomous building is a building designed to be operated independently from infrastructural support services such as the electric power grid, gas grid, municipal water systems, sewage treatment systems, storm drains, communication services, and in some cases, public roads.
Advocates of autonomous building describe advantages that include reduced environmental impacts, increased security, and lower costs of ownership.
[3][4] The 1990s saw the development of Earthships, similar in intent to the Ark project, but organised as a for-profit venture, with construction details published in a series of three books by American architect Mike Reynolds.
In 2002, British architects Brenda and Robert Vale wrote:[5]It is quite possible in all parts of Australia to construct a 'house with no bills', which would be comfortable without heating and cooling, which would make its own electricity, collect its own water and deal with its own waste...These houses can be built now, using off-the-shelf techniques.
Autonomous buildings can increase security and reduce environmental impacts by using on-site resources (such as sunlight and rain) that would otherwise be wasted.
Other impacted resources, such as oil reserves and the retention of the local watershed, can often be cheaply conserved by thoughtful designs.
Autonomous buildings are usually energy-efficient in operation, and therefore cost-efficient, for the obvious reason that smaller energy needs are easier to satisfy off-grid.
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.
Some builders are installing waterless urinals and even composting toilets that eliminate water usage in sewage disposal.
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.
This means that a typical one-story house with a greywater system can supply its year-round water needs from its roof alone.
[7] To reduce dirt and bad tastes, systems use a metal collecting-roof and a "roof cleaner" tank that diverts the first 40 liters.
Sludge settles to the bottom of the septic tank, is partially reduced by anaerobic digestion, and fluid is dispersed in the leach field.
However, septic tanks remain popular because they permit standard plumbing fixtures, and require few or no lifestyle sacrifices.
Composting or packaging toilets make it economical and sanitary to throw away sewage as part of the normal garbage collection service.
If a water-absorbing swale for each yard is combined with permeable concrete streets, storm drains can be omitted from the neighbourhood.
In these climates, a solar installation might not pay for itself or large battery storage systems are necessary to achieve electric self-sufficiency.
Commercially available wind turbines use sealed, one-moving-part AC generators and passive, self-feathering blades for years of operation without service.
In the Great Plains of the United States, a 10-metre (33-foot) turbine can supply enough energy to heat and cool a well-built all-electric house.
If the difference in elevation is above 30 metres (100 feet), and the stream runs in all seasons, this can provide continuous power with a small, inexpensive installation.
In rural areas the grid's cost and impacts can be reduced by using single-wire earth return systems (for example, the MALT-system).
Modern residential chargers permit the user to set the charging times, so the generator is quiet at night.
[17][18] Recent advances in passively stable magnetic bearings may someday permit inexpensive storage of power in a flywheel in a vacuum.
Some buildings have been aerodynamically designed so that convection via ducts and interior spaces eliminates any need for electric fans.
If a small heater is available for the coldest nights, a slab or basement cistern can inexpensively provide the required thermal mass.
Also, small changes in lifestyle, such as doing laundry, dishes and bathing on sunny days, can greatly increase their efficiency.
Pure solar heaters are especially useful for laundries, swimming pools and external baths, because these can be scheduled for use on sunny days.
Annualized geo solar buildings often have buried, sloped water-tight skirts of insulation that extend 6 metres (20 ft) from the foundations, to prevent heat leakage between the earth used as thermal mass, and the surface.
Refrigerators and air conditioners operating from the waste heat of a diesel engine exhaust, heater flue or solar collector are entering use.
[23] Skilled, intensive gardening can support an adult from as little as 100 square meters of land per person,[24][25] possibly requiring the use of organic farming and aeroponics.
