Aug. 18, 2008, Phoenix, Arizona:  On a 5-acre lot in the far western reaches of the Valley of the Sun in central Arizona stands the Earthship, a prototype of the home of the future.  It is totally self-sufficient, approximately 4,000 square feet, and produces energy rather than consuming it.  This project has been an 8-year labor of love by Robert Schafer, a college professor and earth preservation enthusiast.

The home was designed by New Mexico architects, Michael Richards and Alix Henry, who have been developing and improving the concept for 15 years.  Residents will grow their own food inside and outside, live comfortably in a spacious home with spectacular desert views and never receive an electric, water, or sewer bill.  Moreover, they will know that their home actually contributes more to the environment than it takes away.

Using concepts and drawings from Reynolds, Schafer has built the entire house himself from the ground up.  Workers were hired only when help was needed for operations such as installing roof trusses.  Schafer's enthusiasm is contagious as he conducts a tour of the Earthship during one of the recent open houses held at "Whispering Ranch", as the area, located between Phoenix and Wickenburg, Arizona, is called.

The design uses several techniques that effectively minimize the ecological footprint of the structure while providing a comfortable living environment. The structure is built into the end of a south-facing gully and is recessed into the earth to about windowsill height.  That brings the floors to approximately three to six feet below grade and helps cool them to the natural temperature of the earth (about 65 degrees Fahrenheit).

Six circular rooms, approximately 18 feet in diameter, are constructed of stacks of tires packed with earth resulting in walls that are at least three feet thick.  They are then covered by adobe to hide and weatherproof the tires, then bermed 20 feet out on the western, northern and eastern exposures.   Steel reinforcing rods, run vertically through the tire centers, to stabilize the stacks.  The top of each chamber is a steel reinforced dome with an operable vent to release warm air to the outside.  The high thermal mass of the structure keeps the inside far below the local outside temperatures, which often exceed 110.

The rooms all enter onto a common mezzanine looking down over a living room with a waterfall and full size banana, and other fruit trees growing inside.  The main living room wall is all glass and faces south.  The roof is sloped to allow the sun to penetrate through the living room and into the circular rooms in the winter to warm them.  The angle of the roof prevents solar heat gain in the summer by blocking entrance of sunlight into the home.

The rubber membrane roof (light colored to prevent solar heat gain) collects water from the infrequent rains and drains it into three interconnected, underground, 11,000 gallon storage tanks.  Local records indicate that annual rainfall in the area is between 10 and 12 inches.  With a 5,000 square foot roof, at least 31,000 gallons of rainwater would be collected annually. With reuse of grey water, the Earthship uses only about one tenth of the water of a conventional house or about 30 gallons a day. At that rate, a year's supply of rainwater will last nearly 34 months.

Water entering the house from the tanks is filtered.  Potable water runs through further filtration and is piped to the kitchen and bathroom sinks.  After use, gray water from the sinks and shower enters more than 100 feet of indoor planters where it is recirculated, allowing the plants to both receive nutrients and to clean the water.  From the planters the gray water is pumped to the toilets for flushing into a conventional septic tank.  From the septic tank, effluent is then diverted into an exterior grove of mango and avocado trees as a natural pretreatment prior to being discharged into a traditional septic field.

The electrical load is reduced to a fraction of that of a conventional home by judicious selection of high efficiency appliances.  What little electrical power is needed is provided by a solar power system.  A  photovoltaic system comprised of four solar panels and twenty four deep discharge batteries which furnish both direct current (DC) and alternating current (AC) to the house.  Both AC and DC receptacles will be available in each room.  Cooking will be with propane.  Water heating will be by direct solar energy. One of the highest energy costs in a conventional home is heating and cooling.  The natural temperature of the earth helps to maintain the Earthship at a comfortable 65 degrees.  Additional cooling is by convection.  Three 18-inch diameter “air tubes” are buried 6 feet below grade and run horizontally from the low point of the living room approximately 60 feet to daylight in the gully.  When roof vents in each room are opened, warm air rises out of the house drawing earth-cooled air in through the tubes.

A major feature is that many of the building materials are natural or recycled.  The tires are used and not suitable for vehicle use.  Earth for wall fill and adobe is obtained from excavation and nonload-bearing walls are interspersed with empty soda and beer cans and bottles to displace concrete and further reduce the standard building materials required for construction.

As a prototype, the Earthship cost more than similar homes built from scratch.  Currently, investors are being sought to help complete the project.  Schafer has developed many new techniques from this effort and is planning to construct several more similar projects in the area.

One obstacle to be overcome is the acceptance of this type of residential construction by building codes and local building inspectors.  Until this is accomplished, these homes will be more costly and difficult to permit and build.  Anyone considering a project of this type should meet early with local building officials to review the methods to be used.  Prior approval is essential for timely completion.

Although the techniques used here are not new, their combination in a single residence is the unique concept that sets this project apart from conventional homes.  Most true environmentalists have long since realized that society must find more efficient and less wasteful methods for doing nearly everything we do in order to preserve the planet for future generations.  The Earthship represents a major step forward in this direction.  We hope to see many more of these residences built in the future. For additional information, contact Robert Schafer at 602.334.5421 or by email: resassociates@hotmail.com.