Again, please send me all of your thoughts and feedback. We’ve got time to tweak yet!
The Hexayurt (http://hexayurt.com) is a practical global housing solution that has found champions in groups as diverse as the Amritanandamayi Ashram, the American Red Cross and the US Department of Defense. A $200 family home that includes utilities like toilets, electrical light, water purification and a stove will kick start a global revolution in the lives of the poorest. This proposal will show how to achieve this goal.
Standard materials often come in 1×2 sizes, like 4′x8′ plywood. A Hexayurt is built with whole and half sheets of any appropriate 1×2 material. Lightweight materials can be fastened into a building with box closing tapes, which have breaking strains of up to 150 pounds per inch yet cost pennies per foot. These cheap tensile materials are a key enabling technology for the Hexayurt building.
The best material is a honeycomb cardboard material called Hexacomb. (http://www.pregis.com/Products_NA/ProtectivePackaging/Hexacomb/Structura…) Hexacomb was used in permanent buildings in California in the 1980s but fell from favor when building codes changed. However, it is suitable for permanent dwellings and costs around $10 per sheet. It can be insulated with blown cellulose (shredded newspaper) and faced with thin aluminum (think soft drink cans) for long term durability. In short, it is a very cheap, green structural insulated panel (SIP.)
Panels can be assembled in the field, starting with a compressed honeycomb block (i.e. the hexagonal cells are closed, forming a solid block) and two large sheets of paper-backed aluminum. The honeycomb is stretched out, opening the hexagonal cells, and coated with glue using a roller. It is then glued to the foil facing sheets, forming a rigid panel. (reference Mark Jacobson of http://hexacomb.com) This allows an entire building to be fabricated from a 6′x1′x1′ box for easy shipping.
Alternatively, polyisocyanurate insulation boards can be used. They cost $15-$30 each and the US building industry uses over 1,000,000 each day.
12 panels make the basic Hexayurt. 6 boards are used whole, on their long edges, to form a hexagonal wall. Six more are used to form the roof, which is a simple cone made of 4′x8′ panels cut in half diagonally. The building is taped together and guyed down like a tent. Windows and doors are cut to taste. It takes about two hours.
12 board, 8′ Hexayurts shrug off 40-60 mph winds without difficulty. Larger units can also be made but they require stronger materials. Folding units are also possible.
People download the plans from the internet and build their own shelters for recreational use in harsh desert climates.
This works. In its own way it as shocking as the geodesic dome.
The Utilities Package
Without basic services like sanitation and light, a shelter is only a small step. To achieve an integrated solution requires collaboration.
Toilet technology varies greatly by climate among other factors. The Sulabh toilet (http://www.sulabhinternational.org/) can cost as little as $10. Thermophilic composting toilets are another good option. It is a specialized design challenge.
From Solar Cookers International (http://solarcookers.org) we take the CooKit. Solar cookers can also purify water by heating it to 160F for several hours, killing all pathogenic organisms. A simple melting wax indicator (the WAPI) shows when the water is purified. The materials for the CooKit are the same as those of the Hexayurt itself – foil-covered cardboard.
For cooking and heating, we suggest an efficient biomass stove like a wood gasification stove (http://woodgascampstove.com) or a rocket stove (http://aprovecho.org/). The gasification stove requires 3W of power (from rechargeable batteries) but is incredibly clean burning and efficient.
Power is burgeoning with innovation. A simple approach is a large solar panel which recharges AA batteries using a 15 minute charger. Each person takes their empty cells, places them in the charger, waits 15 minutes, then takes their electricity home. Another approach is a pull-cord battery charger (http://potenco.com/) which if used one per village could cut costs even more.
Cold cathode (CCFL) interior lights are as efficient and robust as LEDs, but produce broad, even illumination suitable for reflecting off the reflective roof of the Hexayurt, lighting the whole building. The indirect light allows the human eye to adapt to make best use of light, making the Hexayurt seem much brighter than the light meter reading would suggest.
Cooling and refrigeration are hard to provide on limited power budgets. Clay evaporative cookers (http://en.wikipedia.org/wiki/Pot-in-pot_refrigerator) can provide food storage. Ducted high efficiency fans (http://sleepbreeze.co.uk) could, in future, provide affordable cooling for individuals vulnerable to thermal stress.
Together these simple technologies can provide the same basic services which those in industrialized nations take for granted for a tiny fraction of the price.
The role of the Hexayurt Project is integrate a set of technologies to provide necessary services in a culturally and regionally appropriate way. This is a whole systems thinking design optimization challenge. (see diagram)
The next step for the Hexayurt Project is to go beyond demonstrations and into an experimental deployment. There are two groups that are interested in working with the system, validating the technology, and possibly moving towards adoption.
The first group is the US Department of Defense. Hexayurts have been built at three US DoD demonstrations (Strong Angel III, Combined Endeavor 07, STAR-TIDES http://star-tides.net) and have attracted significant interest from Dr. Linton Wells II (former Chief Information Officer of the DoD.)
The second group is the Mata Amritanandamayi (Ammachi) Ashram in Kerala, an NGO which has a large free housing program. In fall of 2006 Amma asked us in person to come to the Ashram and teach the technology to her community.
The role of the Hexayurt Project is to solve the fundamental engineering problems and publish the results for the world to use. The fact we have interest from such diverse groups validates the generality of the technology.
However, because we do not patent our copyright our work, so that it is freely available to everybody for any purpose, we cannot easily find funding. The disaster relief and poverty alleviation charities are strongly oriented towards existing off-the-shelf solutions, rather than building technologies. US military funding system is poorly geared towards small, lightweight projects without heavy institutional backing. We need help to turn the non-funding institutional interest that we have already achieved into action.
Once we have a village-level demonstration, NGOs and government groups can take the results and work with their existing suppliers to build Hexayurts and utilities packages to their own specifications. But until we prove that it works in the field, the open nature of our intellectual property works against us.
In short, the Hexayurt Project needs funding to demonstrate the technology in a village setting and to document the results clearly and scientifically. We would anticipate working closely with groups with serious field resources to do these tests, of course.
We would anticipate four cost centers
* Subsistence living expenses for Lindsey Darby and Vinay Gupta.
* International travel to test sites.
* Equipment and test units.
* Professional services (one video shoot, some engineering analysis.)
Based on our current cost of living, and reasonable projections for other expenses, we would expect the prize to cover our full time engagement and all associated travel, materials and services for 18 months to two years. Because of institutional lag, however, it may prove more effective to use the money over five years. There may be long periods when very little can be done while we wait for institutional decision making and building seasons, for example.
Current aid programs are inadequate for the reality of refugee life. Tents rot in a year in the sun. Gathering firewood exposes people to needless risk. The Hexayurt Project can deliver an integrated, whole-systems based refugee response package which is designed around the decade-long refugee context, at a price comparable to relief tents. The Hexayurt Utilities Package was designed in response to the Sustainable Settlements Charrette (http://www.carebridge.info/carebridge/community/charrette2.html).
In the developing world, we would anticipate shipping raw materials and a large field fabrication team into the disaster area to work with people to make their own panels and emergency homes. (http://www.appropedia.org/Hexayurt_rapid_deployment#Flat_Packed_Cardboar…)
In the developed world, Hexayurts can be made from insulation boards, sheltering around 500,000 people per day. The American Red Cross is enthusiastic about this plan (http://disastr.org)
By bringing down the cost of essential services, and demonstrating an alternate model of infrastructure, we can change how governments approach poverty for the better and start to provide for the millions. We hope that people will manufacture hexayurts all over the world once we have demonstrated what is possible.
Lindsey Darby is an environmental sciences student with a strong interest in poverty issues, societal resilience and economics.
Vinay Gupta is an engineer. He dropped out of college to help start a medical software company, and has worked in many different fields. He volunteered with the Rocky Mountain Institute (http://rmi.org), co-authoring a paper for the Danish EPA and co-editing “Small is Profitable” (http://smallisprofitable.org) and “Winning the Oil Endgame” (http://oilendgame.com).
For more information, please see http://hexayurt.com/bfi