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It’s within 1% of the maximum length, but has a little bit of word-level slack that could be trimmed to get in an additional sentence. Larger scale cuts and re-arrangements are perfectly plausible also.
Our goal is to produce a proven public domain plan for a $100 home, similar to the Dymaxion Deployment Unit, suitable for both emergency and permanent use. This building can be made from simple materials like foil-coated cardboard, or from sophisticated composites, depending on budget and application. Because it is public domain we anticipate the design will become a standard form for simple buildings all over the world. So far we have proven the concept and gathered considerable interest from major institutions, and with your support, we can finish the job by proving the design works in all major climates, and with a broad variety of local materials and manufacturing techniques. This is a validation challenge with extremely low risk and very, very high returns.
Furthermore, all of our work to date is online and in the Public Domain.
Let us start with the basics. In America, the Hexayurt shelter is specified to be made from 12 sheets of Thermax HD. Thermax is a common agricultural insulation product comprising a 4′ x 8′ x 1″ (or thicker) sheet of polyisocyanurate insulation (akin to styrofoam) sandwiched between two thin sheets of aluminum foil about the thickness of a soft drink can. It retails for about $25 to $40 per sheet, giving a 166 square foot microbuilding for $300-$500. A board weighs less than 10 lbs, with an expected life of 10 years.
To make a Hexayurt, six of these sheets are cut in half along their diagonal, and taped into six connected isosceles triangles forming a hexagonal cone four feet high and sixteen feet across. Six more boards are placed on their long sides and taped together into a wall, then the roof cone is taped to the wall. Many modern tapes have a breaking strain of 150 lbs per inch of width, and 10 or 20 lbs per square inch of adhesion, so a 3″ tape applied to all seams is sufficiently strong for this building to stand in 60 mile per hour winds. This structure has similarities to both the geodesic dome and the mongolian yurt. The advantage of this shape that is uses standard 4′ x 8′ building materials with no waste and minimal cutting or measuring.
To make this simple design work many critical details must be observed – correct formation of the anchor points which keep the building on the ground, correct coating of the tape to prevent ultraviolet light degradation, correct match of materials to climatic zone. We simplify here for brevity.
To reach $100 per home, we must turn to using local labor for the manufacturing processes, and switch to a different material: hexacomb cardboard. Hexacomb is a kraft-paper honeycomb material that was used for building permanent residences in California in the 1980s, and is widely used in the packaging industry. The honeycomb ships as a solid block which can be expanded by hand and glued to a paper-backed foil sheet to produce a panel. The panels may be filled with blown cellulose (shredded newspaper) insulation for greater energy efficiency. The reflective foil face helps to shed the sun in hot areas, greatly increasing the thermal efficiency of the shelter.
This process will allow us to create a kit home which fits in a 6′ x 1′ x 1′ box, costs around $100 per unit, and is erected with local labor. The Hexacomb-type core material can be produced in most countries, as can the foil facing materials and the tape. This approach is validated by Mark Jacobson (http://Pregis.com,) who has been working with these materials for over 20 years, and passes the “smell test” for practicability in the field.
Both the hexacomb cardboard and the Thermax these materials derive their durability from the aluminum layer which faces the sun, preventing ultraviolet light degrading the shelter. This makes them ideal as a replacement for disaster relief tents which are frequently used to house refugees, but rot in the sunlight after only a couple of years, while the refugees themselves often remain in place for decades. The same logic applies to housing for the very poor. An additional feature is that the completed building is light enough to be carried by four or five people for many miles, so it can be moved without being taken down, or the tape on the panels can be cut and the building re-erected in a different place. This property allows refugees who are sheltered in these buildings to be resettled in their original locations with their new homes if peace permits them to return home.
The Hexayurt has been demonstrated to the American Red Cross, and many members of the US Department of Defense, including General Ward of Africa Command. It is universally thought of as being an extremely promising technology, with a great future ahead of it.
Beyond sheltering we come to the other needs of the poor, the refugees, and the displaced.
We believe that for an additional $100 per family, a basic but complete family utilities package can be provided, including water purification, solar cooking, energy efficient biomass (i.e. wood or dung) cooking, efficient electrical lighting, and a sanitary toilet system. The archetypal form of that utilities package is as follows:
The CooKit solar cooker, from Solar Cookers International (http://SolarCookers.org) or a similar device provides efficient energy capture for cooking, and for solar water pasteurization. (Water held at or above 160F for several hours is completely disinfected, and a simple solar cooker can do this almost anywhere in the world.) This is cardboard and tin foil, the same basic elements as the house.
A rocket stove or wood gasification stove (http://Appropvecho.org, http://Spenton.net) provides efficient biomass cooking. Neither design is patent encumbered. The WGS requires a little electricity (3W) to operate, however. $5 – $15.
Village solar based on AA batteries. A central solar charger station costing around $400 will charge 4AA cells in 15 minutes for a few cents per use. One system may serve as many as 80 households, making their per-home cost $5. 4AA rechargeable cells cost $5 in bulk. Every few days each household walks to the charger, waits in line, and charges their cells. This also allows for cell phone charging. $10 per household all told. Rayovac’s IC3 technology is ideal, although slipping out of availability.
An interior light based on either CCFL or LED technology, optimized to produce even light in an interior so that the human eye dark-adapts for maximum perceived brightness, is also run from the AA solar charger. $10 or less per household. Energizer Double Bright is an ideal base technology.
A simplified toilet. There are a variety of possible designs available, but for practical reasons, we favor an enclosed body thermophilic composting toilet. This is an area under active development by many parties, and our intention is to work with partners like Joseph Jenkins (Humanure Handbook) or Robert Patterson (BIPU) to deploy a suitable solution. $40?
You will note that so far we have not described any heavy engineering challenges. This is because there are none. Everything we want to do consists of testing extremely simple or off-the-shelf systems formally so that their efficiency and effectiveness can be proven, and building test shelters from a variety of materials in different parts of the world so that people can know, for sure, how these shelters and utilities systems perform in the field.
All of our intellectual property (so far) is in the Public Domain so anyone can replicate our work. The project is far enough advanced that the challenge is getting to the first 10,000 deployed units.
Our plan is to demonstrate that the system works, do a pilot project or half a dozen pilots, and document everything possible on video and in pictures and text on the internet. The simplicity and openness of the designs aids technology transfer. The Department of Defense is extremely enthusiastic (see http://star-tides.blogspot.com for an account of one demonstration where Hexayurts were built) as are the Red Cross, who value the idea for using Hexayurts for responding to natural disasters or terrorism in America. Up to 500,000 people per day can be sheltered using materials already in the building supply chain. We expect these groups and other NGOs, private companies and individuals simply to observe what we have shown to work, and copy the designs using the materials they have access to. There is no economic model beyond “publish” and, once that is done, get day jobs.
Our primary qualification is in this document: what we have done. I worked at the Rocky Mountain Institute as a volunteer, co-editing “Small is Profitable” and “Winning the Oil Endgame,” and co-authoring “A Whole Systems Framework for Sustainable Consumption and Production.”) Before this I was a software engineer. My partner, Lindsey Darby, has make significant contributions to this work, but is still in university and therefore has no long track record.
We hope you will appreciate and understand the practicality and simplicity of our work.