The Billboard Earthbag Project

Each year the Society for Environmental Graphic Design sponsors a contest to recognize the best in environmental graphic design. This year’s Juror’s Award went to Norman Lee and Charles Houser for their Billboard Earthbag Project.

The designers say: “Because most conventional sandbags are fabricated from polypropylene, they are very vulnerable to UV rays and quickly begin to deteriorate when exposed to the sun. Consequently, earthbag shelters need to be plastered to maintain their durability during extended use.The Billboard Earthbag Project envisions using billboard vinyl as an alternative material for earthbags. Polyvinylchloride (PVC) or vinyl, a virtually indestructible, UV-resistant material that cannot be incinerated because of the toxic gases it would emit, represents a substantial portion of the PVC in the world’s overburdened landfills. Because of its durability and imperviousness to the sun and other elements, billboard PVC is an ideal material for reuse.”

“The reuse of billboard vinyl in earthbag construction mitigates the impact of global warming in two ways. Transforming this landfill-bound material into another useful product helps lessen landfill overflow worldwide. It also eliminates the need to protect earthbags from UV rays, resulting in more robust emergency shelters that can be used longer to lessen the human suffering caused by natural disasters.”

“As a visual concept, each billboard shelter stands as a symbolic gesture of sustainability. Beyond its environmental benefits, the strategy of reusing billboard vinyl visually recontextualizes the nature of billboards, which are symbols of mass consumerism and a pervasive form of visual pollution in our world. This concept does not seek to generate imagery, but instead appropriates existing commercial imagery as a metaphor for global recycling and reuse. Assembled together into a shelter, the earthbags create a dynamic and vibrant pattern of collaged images and text from around the world, dramatically suggesting a unified, international gesture of sustainability, hope, and humanitarianism.”

According to the jurors, they "were intrigued by this project as an example of ‘cradle-to-cradle’ design pertinent to the signage industry. Utilizing intrinsic qualities of billboard PVC—UV resistant and near indestructible—this concept proposes the creation of dwellings from recycled material and imagery. The idea takes the recycling of billboards, street banners, and print graphics—already employed by art museums in the creation of second-use products—to another level. Truly inventive!"

This all sounds pretty good, and might well work if the billboard material were cut and sewn into bags. One obvious disadvantage of the idea is that since PVC is toxic when burned, this would present a potential hazard to the occupants, but of course this is true of many modern building materials. PVC poses a great risk in building fires, as it releases deadly gases long before it ignites, such as hydrogen chloride which turns to hydrochloric acid when inhaled. As it burns it releases yet more toxic dioxins. Additionally, vinyl does outgas highly toxic VOCs over time. Fortunately most of this danger would have passed with the use of recycled signs, but this could also be an issue.

Oil Dependency

Having just finished reading “A Declaration of Energy Independence: How Freedom from Foreign Oil Can Improve National Security, Our Economy and the Environment,” by Jay Hakes, my mind is spinning with all of the issues that this brings up. Hakes was the head of the Energy Information Administration at the U.S. Department of Energy during the Clinton administration, so he knows a fair amount about the topic.

He makes a pretty good case that not only will shaking the U.S. reliance on foreign oil help in all of these ways, but that it is possible. He points out that after measures put into action after the oil shortages in the 1970’s, the U. S. actually did cut its reliance on foreign oil by half…for a short while. This was accomplished through a combination of government resolve to solve the crisis and the public’s willingness to adopt some simple conservation measures. People actually did drive less and at slower speeds; they turned down their thermostats in the winter and up in the summer; they began to install solar water heaters.

Of course times have changed, and now we are painfully aware of the costs that we face from not having continued to boldly deal with these issues. The true cost and burden of our reliance on oil (not just foreign oil) will be paid by future generations. There is little doubt that the Iraq War is a battle for control of oil resources, for which we are paying dearly in dollars, blood, and tarnished reputation. There is little doubt that global climate change, fanned by our burning of fossil fuels is wreaking havoc with rising sea levels, loss of crops, loss of biodiversity, and increasing severity of storms.

Hakes points out that because of the time lag that often occurs between when tough mitigating measures are adopted and when their effects are noticed, there is frequently little resolve among politicians to act because unpopular measures usually don’t bring votes, especially if voters don’t see positive results.

It has taken a few centuries for us to get into this mess. For over 99% of the time that Homo sapiens has been roaming earth, we have done just fine without burning fossil fuel. Even during the great leap into agriculture from hunting and gathering, we relied solely on our labor, with the help of a few beasts of burden. Then, as ecologist William Catton writes, “Homo sapiens attained a kind of superhumanity by learning to convert the heat energy from fire into mechanical energy by means of various engines.” This discovery has jettisoned humanity into the industrial age, and we have comfortably settled into this new way of life, congratulating ourselves on our modern ways.

Now, with the peaking of fossil fuel supplies and increasing world-wide demand, there is only one direction for the price of oil to go: up. With spiraling prices, all aspects of our economy will be affected. The cost of living in this modern world will continue to increase.

But this simple fact may ultimately be our salvation, because economics will force us to find alternative ways of living, and these will inevitably lead us to cleaner, renewable forms of energy. The inexorable laws of economics will eventually force us to address these thorny issues, even when politicians and an unwilling public dig in their heels to avoid change. It will cost too much to do otherwise!

Of course we can choose to cushion the blow of economic and climatic upheaval by making wise decisions now. We can invest in renewable energy now. We can drive cleaner, more fuel efficient cars now. We can walk. We can grow more of our own food. We can make our homes more energy efficient. We can buy only what we really need. We can do all of these things…and we will be much healthier for it!

Building with Unbonded Pumice

Dr. Owen Geiger and I have just found that a book published in 1990 in Germany, Building with Pumice, written by Klaus Grasser and Gernot Minke, describes experiments done in the 1970’s at the Research Laboratory for Experimental Building at Kassel Polytechnic College in Germany that have considerable bearing on the history of earthbag building.

Most of the book is about the physical properties of pumice, how to obtain and process it, and how to make blocks or walls with pumice/cement, but the fifth and final chapter, titled “Building with Unbonded Pumice,” describes how they began to investigate the question of how natural building materials like sand and gravel could be used for building houses without the necessity of using binders. The use of fabric-packed bulk material was found to be a cost-efficient approach. They used pumice to pack in the bags, because it weighs less and has better thermal insulating properties than ordinary sand and gravel. Their first successful experiments were with corbeled dome shapes (an inverted catenary) which was obtained with the aid of a rotating vertical template mounted at the center of the structure.

1978, a prototype house using an earthquake-proof stacked-bag type of construction was built in Guatemala. They used cotton bags soaked in lime-wash to protect the material from rot and insects. When flattened, the bags measured roughly 8 X 10 cm. Vertical bamboo poles placed on both sides of the bags and interconnected with wire loops gave the stacked bags stability. The bamboo rods were fixed to the foundation and to the horizontal tie beam at the top.

Obviously the concept of constructing homes with fabric bags of mineral material predates Nader Khalili’s earliest experiments by many years, and I was certainly not the first to experiment with filling earthbags with pumice! The entire chapter is reproduced as an article at www.greenhomebuilding.com.

Tulou Chinese Architecture

I received an email from Professor Sunny Cai, who teaches architectural design at a college in Beijing , China. He mentioned his interest in ancient Chinese architecture, especially the earthen buildings called “tulou,” and he sent me some pictures of these rammed earth buildings.

I had never seen anything quite like them, so I queried him further about how they were made and used. He replied, “The foundation was built with rocks, 2 feet high all around. The juice of glutinous rice and some lime is mixed into the earth for strength, and then sliced bamboo, reeds, and sometimes pieces of wood are also used.”

This picture was taken in front of a rammed earth building with Sunny Cai and his students.

I did some further internet research and found out more about these interesting structures. Tulou are traditional communal residences in the Fujian province of Southern China, often of a circular configuration surrounding a central shrine. Some of these vernacular structures were constructed of cut granite or had substantial walls of fired brick. The end result is a well lit, well-ventilated, windproof, earthquake resistant building that is warm in winter and cool in summer.

There are more than 20,000 tulou in southern Fujian, and these were designated as a UNESCO World Heritage site in 2008 as “exceptional examples of a building tradition and function exemplifying a particular type of communal living and defensive organization, and, in terms of their harmonious relationship with their environment".

Actually the Tulou were built by a minority called the Hakka, who were originally Han who fled south to escape war and famine during the Qin Dynasty (221-206 BC). As they gradually moved they changed the local architecture by incorporating Han styles and that produced the tulou. Not only were the high walls built for defense but they were also the result of traditional Han architecture. Tulou were mostly built between the 12th to the 20th centuries. The oldest one was constructed over 1,200 years ago and is regarded as a “living fossil” of the construction style of central China.

There are three types of Tulou. The Wufeng has three halls and two side rooms and are said to be the result of a redesign of the Han courtyard. The oldest tulou are the rectangle ones, and the most emblematic ones are round. They are typically designed for defensive purposes and consist of one entrance and no windows at ground level. The biggest round one can have up to five stories with three interior rings. The largest houses cover over 40,000 m² and it is not unusual to find surviving houses of over 10,000 m². Most round tulous are three or four stories, with family kitchens and livestock on the ground floor. The next floor becomes a storage room for food and furniture (with no windows), and above that are the bedrooms.

These structures are exemplary of sustainable architecture in that they are built of local, natural materials with simple techniques. They have good thermal attributes, with the massive earthen walls to help buffer temperatures. They are obviously built to last, and house many of the necessities for life. And they embody a communal life style that conserves energy and resources; these represent a form of ancient co-housing.

California's Green Building Code

California has adopted the nation's first statewide green-building standards, which will become mandatory in 2010. The new California Green Buildings Standards Code requires builders to reduce energy use by 15 to 30 percent beyond current standards and use more recycled materials. Some of the code will be mandatory, while other parts are just suggested. This is a significant recognition that energy and resource conservation is essential for the welfare of state residents, and hopefully this officially sanctioned consciousness will spread to other states.

These new codes include basic passive solar mandates: "When site and location permit, orient the building with the long sides facing north and south. Provide exterior shade for south-facing windows during the peak cooling season. Provide vertical shading against direct solar gain and glare due to low altitude sun angles for east- and west-facing windows."

For renewable energy, the codes says, "Use on-site renewable energy sources such as solar, wind, geothermal, low-impact hydro, biomass and bio-gas for at least 1% of the electric power."

For water conservation, the code says, "A schedule of plumbing fixtures and fixture fittings will reduce the overall use of potable water within the building by 20%, and provide water efficient landscape irrigation design that reduces by 50% the use of potable water beyond the initial requirements for plant installation and establishment."

"Each building shall further reduce the generation of wastewater by one of the following methods: The installation of water-conserving fixtures (water closets, urinals) or utilizing non-potable water systems (captured rainwater, graywater, and municipally treated wastewater
(recycled water)."

For materials to be specified for construction, the following is mandated:

• Select building materials or products for permanent installation on the project that have been harvested or manufactured in California or within 500 miles of the project site.
  
• Select bio-based building materials and products made from solid wood, engineered wood, bamboo, wool, cotton, cork, straw, natural fibers, products made from crops (soy-based, corn-based) and other bio-based materials with at least 50% bio-based content.
  
• Employ wood-based materials and products comprising at least 50% of a major building component, such as framing, flooring, or millwork, which are certified by one of five listed sustainably harvested certification programs.
  
• Use materials made from plants harvested within a ten-year cycle for at least 2.5% of total materials value, based on estimated cost.
  
• Use salvaged, refurbished, refinished, or reused materials for a minimum of 5% of the total value, based on estimated cost of materials on the project.
  
• Use materials, equivalent in performance to virgin materials, with post-consumer or preconsumer recycled content value (RCV) for a minimum of 10% of the total value, based on estimated cost of materials on the project.
  
• Use cement and concrete made with recycled products, fly ash, raw or calcined natural pozzolan, blast furnace slag (as a lightweight aggregate) .
  
• Select materials for longevity and minimal deterioration under conditions of use.
  
• Select materials that require little, if any, finishing.
  
• Select materials that can be re-used or recycled at the end of their service life in the project.
  
• Select materials assemblies based on life cycle assessment of their embodied energy and/or green house gas emission potentials.

"Provide readily accessible areas that serve the entire building and are identified for the depositing, storage, and collection of non-hazardous materials for recycling, including (at a minimum) paper, corrugated cardboard, glass, plastics and metals."

Environmental and health-related items establish specific limits on VOC emission of materials used within the structure, as well as regulate ventilation, CO2 emissions, tobacco smoke, lighting, outside views, and noise transmission.

Additional recommended measures include:

• If feasible, disassemble existing buildings instead of demolishing to allow reuse or recycling of building materials.
  
• Utilize a Frost-Protected Shallow Foundation.
  
• Use pre-manufactured floor and roof systems to eliminate solid sawn lumber whenever possible.

The code also identifies site improvements including bicycle storage and designated parking spots for low-emissions vehicles.

I have been advocating most of these measures at www.greenhomebuilding.com for many years now, and it is heartening to see them being officially sanctioned. This is a far-reaching and well-considered attempt by California legislators to establish requisites for living sustainably. If there are going to be building codes, they might as well be green! Yeah California!

Strawboard Panels

Strawboard building panels are a kind of structural insulated panel (SIP) designed to replace 2x4 stud and drywall construction for both interior and exterior walls, as well as provide load and non-bearing ceilings, roofing, doors, flooring, and prefabricated buildings. These environmental friendly, solid panels are made of all natural fibrous raw materials, mainly wheat and rice straw. The durable panels feature thermal and acoustic insulation as well as fire and termite resistance and are available for a variety of applications to speed up the construction processes. While these have been used in over 20 countries for more than 50 years, strawboard panels have only been introduced to the U.S. in the past few years.

Strawboard panels have a solid core of compressed wheat or rice straw. High pressure and temperatures forces the straw to release a natural resin that binds the fibers together. The compressed panels are then covered with either paper liners or OSB that is adhered to both sides with water based non-toxic glue. The standard panel measures 4 feet by 8 feet by 2-1/4 inches to 8 inches, weighing from 140 lbs. to 440 lbs. each. Custom panel sizes are available ranging from 3 feet to 12 feet long.

The panel's high density and low oxygen content does not support combustion. Since the panels do not contain added resins, alcohol, or other chemicals, no flammable vapors are produced. The panels have an R-value of between 3 and 25, depending on the composition and thickness. For permanent protection against insects and fungal decay and additional fire resistance, the boron compound polybor can be factory added to the core.

The product's workability is similar to wood as it can be sawn, drilled, routed, nailed, screwed, and glued. Lightweight wall attachments such as shelf brackets, picture frames, mirrors, and towel bars can be attached directly to the panel.

Since straw is a renewable by-product of wheat and rice production that becomes available annually, it takes less acreage (by about half) to build an equivalent house than with standard lumber, and which would then potentially preserve that forest for ecological habitat and CO2 sequestration.

See www.stramit-int.com/ for panels available in Europe and www.agriboard.com for panels available in the U.S.

Thermoplan and Zeigel Blocks

There is a manufactured building system that has been gaining popularity in Europe for several years called Thermoplan or Zeigel Blocks. While I have no personal experience with this technology, I can readily see its many advantages. As far as I know this system has not made its way across the ocean to North America. From what I can gather from the websites (referenced below), here are some of the advantages:

Thermoplan or Zeigel Blocks are fired clay blocks which use about 1/3 less energy to make compared to concrete blocks, and about 2/3 less CO2. They are fast, simple and ideal for a self builder to use. About 50% of German homes are made this way and the technology is spreading to other areas of Europe.

Thermoplan systems use Ziegel blocks with a thin bed of mortar, to provide a breathing wall construction system. When combined with woodfibre board they can form a thermally and acoustically high performance shell. The Ziegel blocks come as part of a full load-bearing external and internal wall masonry system, and combine high thermal performance with robustness, speed of build and a breathing wall design.

Because of all the trapped air and the thickness of the walls, these blocks provide reasonable insulation, while at the same time do provide some degree of interior thermal mass for maintaining constant interior temperatures. This is an unusual combination of these two factors in a single wall system.

See www.burdensenvironmental.com or www.natural-building.co.uk for information for this innovative system.