Self-sufficient homes, also known as autonomous homes, are the ultimate in green living dwellings. These homes rely solely on themselves for heating, cooling, electricity, and more. Each self-sufficient home may be configured differently depending upon its climate, location, and the needs and desires of the homeowner.
Systems Used in Self-Sufficient Houses
Autonomous homes can make use of several different types of systems. How they are configured is often decided upon based on the site the house is being built on.
Heating and Cooling
Heating and cooling an autonomous home may mean using several different systems combined with one another. For example, geothermal heating and cooling may be combined with:
- Solar heating: Heating a home through solar power involves ensuring that the solar panels on the roof have unobstructed access to the sun's rays, particularly the angle of the sun during the colder months of the year. This is usually combined with other heating methods such as windows positioned to catch the sun during the cooler months and distribution mechanisms such as conduction, which transfers heat through the house.
- Insulating: Many autonomous homes rely on heavy insulation combined with an airtight surrounding that does not allow the transfer of air between the outside and interior, leading the interior to stay at a more comfortable temperature year round.
- Passive heating and cooling: Passive heating makes use of well positioned windows combined with heavy insulation to warm the house through a combination of the sunlight and body heat. Well placed awnings help bounce the sun off the home in warmer weather, and the right site positioning helps to ensure the house gets the right amount of air and light.
While lights can be generated through the use of electricity, some autonomous homes also make use of passive lighting. Passive lighting means designing your home so that strategically placed windows will catch daylight as the sun moves through the sky, lighting your home during daytime hours with no additional energy. Other lighting systems use LED lights powered by solar, hydro or wind power; LED lights give off less heat, which can keep the home from overheating.
Photovoltaic energy production is used frequently in autonomous homes, and not just for heating. Combined with other systems such as wind turbines, geothermal systems, and hydro turbines that generate energy from falling water, some self-sufficient homes are actually able to feed energy back onto the grid after taking care of their own needs.
Many homes that are self-sufficient in design also contain hydroponic gardens, or they may rely on self-sufficient methods to help water the grass and tend to other non-potable water needs, such as flushing the toilets. While a well is ideal for drinking and bathing water if one can be dug onsite, a way to supplement your water needs for all non-potable uses is to collect, store and reuse rainwater.
Other Attributes of Autonomous Homes
In addition to the many different types of systems used in these types of homes, other careful planning must go into their construction.
Where the house is located is nearly as important as what systems are designed to work with it. Self-sufficient homes that make use of solar power need to be positioned so the sun's rays can be captured efficiently. Homes that make use of wind power or that are passively designed also need to have the climate surrounding the house taken into consideration.
Using the Earth
Some autonomous and passive autonomous homes make use of the natural temperature regulation found beneath the earth's surface. Some homes are sunk or partially sunk beneath the ground to help maintain a consistent temperature without the need for energy to heat or cool it.
Some passive homes make use of the occupant's body heat to help warm the rooms. These homes are often designed with an interior layout that helps to capture body heat as the occupants travel up and down stairs or through the home.
Examples of Self-Sufficient Houses
There are several different autonomous homes in the world making use of these systems.
The Cropthorne Autonomous Home
The Cropthorne Autonomous Home is located in Britain. It uses no space heating systems of any kind - furnaces, woodstoves or boilers. In addition, the house also:
- Is triple insulated to maintain a consistent temperature
- Uses rainwater for most water needs
- Uses composting toilets
HOUS.E+ is an autonomous home built for the 100 Mile House design competition. Its walls are built of compacted earth and fed with a system of hydro turbines to transfer falling water to energy. The rooms are sunk below the earth to help maintain a consistent temperature and a rooftop photovoltaic system generates enough electricity to allow some of the power to be fed back into the grid.
Passive House Estate in Hannover-Kronsberg
The Passive House Estate in Hannover-Kronsberg is one of many passive house projects listed with the Passive House Institute. This highly-insulated estate uses no outside heating or cooling methods, relying on an airtight body, well-placed windows, and body heat to maintain the climate within the house.
Autonomous homes are gaining in appeal as energy bills continue to climb. If you plan on building a new home, consider looking into a home with self-sufficient attributes, and see what you can create.