Green Home Building and Sustainable Architecture

LEED Credit Tracking Software

noreply@blogger.com (Kelly Hart) — Thu, 19 Nov 2009 18:17:00 +0000

Software Advice has released the first in a series of "state of the industry" reports to share their observations on construction software trends over the last year. One of the major trends they reported was the increased demand for software to track LEED credits.

Just as LEED certification has grown in popularity; so too has the need to track the detailed documentation requirements related to earning LEED credits. At their core, projects seeking LEED certification need document control and efficient communication. This is the key functionality that project management software (e.g. EADOC, Procore, e-Builder) offers. Consequently, Software Advice has noticed an increase in adoption of software for LEED projects. Additionally, a number of software companies are now building specific LEED credit tracking modules right into their systems.

Living Walls

noreply@blogger.com (Kelly Hart) — Wed, 21 Oct 2009 18:36:00 +0000

We have all heard about green roofs and know about their environmental advantages, but there is a new concept that is taking root, especially in urban environments: green walls or living walls. Better than the old ivy-covered buildings, which can be adversely affected by the vines, these walls are designed to feature a variety of different plants in a vertical environment, and provide all of their needs for moisture and support right on the wall.

These walls can be either exterior of interior, and they provide advantages in both situations. On the outside they will shade the wall from the intensity of the sun, and thus moderate the temperature considerably, as well as provide lovely textural contrast and beauty. Plant surfaces, as a result of transpiration, do not rise more than 4–5 °C above the ambient and are sometimes even cooler. On the inside they will filter and oxygenate the air, providing a healthier indoor environment, while also creating the calming effect that natural plants tends to have on most people.

Vertical gardens can be grown on just about any type of wall, with or without the use of soil. Many living wall kits come with modular forms that are assembled and applied to a frame that then is affixed to the wall. The most common frame for sale today is a panel that is self-supporting and can be set up independently or attached to a real wall. It is then filled with soil or a soil-less medium and planted. Once the initial panels are in place living walls require little maintenance. They are designed so that their upkeep is about the same as a landscaped garden.

When you combine the obvious environmental benefits of living walls with their sheer beauty I anticipate that we will be seeing many more examples of this wonderful art form. For more details and photos see greenhomebuilding.com.

Super-Insulated Houses

noreply@blogger.com (Kelly Hart) — Sat, 17 Oct 2009 15:02:00 +0000

I am pleased to introduce a new "expert" panelist at www.greenhomebuilding.com. Robert Riversong has created his own form of the Larsen Truss building system, and specializes in super-insulated houses. He teaches these techniques, and many other subjects, at the Yestermorrow School in Vermont.

In an article about his work, Robert states, "I've been using and modifying the Larsen Truss super-insulated wall system for 20 years and can build a 12" thick wall (R-40+) with no more lumber than a conventional 2x6 house, in part because I eliminate exterior wall sheathing and use t-braces and full 3/4" drop siding over housewrap. And, with the air-tight drywall system instead of vapor barrier and dense-pack cellulose, there's almost no thermal bridging and a 3 bedroom house can be heated with less than a cord of wood per year here in New England.

"I also use native, rough-sawn green full-dimension lumber, rough-sawn subfloor and roof deck, and rough-sawn exterior trim. The load-bearing wall is 2x4 24" oc and the exterior chord of the parallel chord wall truss is a 2x3, extending from sill to rafter tail and attached to studs with rough-sawn 1x4 gussets 24" oc."

"The open wall cavities makes the installation of mechanicals simple, since there is little drilling necessary. The three air barriers (drywall, dense pack, housewrap) make the walls virtually impermeable to infiltration. The dense pack cellulose makes the walls highly fire resistant and extremely quiet. Insects and rodents don't like the boric acid used as fire retardant in the cellulose, so these two universal problems are minimized or eliminated. The cellulose is more hygroscopic than wood, so it not only can absorb and release any diffused moisture that might get into the wall cavities but also draws any potential moisture away from the wooden frame, thus protecting it (foam insulations will do the opposite)."

"The only plywood in the house is for door and window boxes, as this makes a better air-tight seal than boards, and for a couple of interior shear walls. Let-in metal t-bracing in exterior and interior load-bearing walls and wooden under-rafter diagonal bracing sufficiently stiffens the structure, particularly once the sealed drywall is installed."

"I find that going from conventional construction to superinsulation adds no more than 5% to the cost of a house and the payback is enormous, both in energy savings and comfort. Some banks are offering higher debt-to-income ratios to mortgagees who buy or build highly efficient homes, since they need so much less income to operate it."

If you have any questions about the Larsen Truss building system or super-insulated homes in general, Robert is happy to answer them. Go to greenhomebuilding.com/ask_the_experts to send your question.

An Alternative Home Tour

noreply@blogger.com (Kelly Hart) — Wed, 16 Sep 2009 15:59:00 +0000

This year’s Twentieth Annual San Luis Valley Energy Fair held in Crestone, Colorado featured three different concurrent homes tours on a Sunday afternoon. It was hard to decide which tour to take, since they all were intriguing. Ultimately the impulse toward simplicity and sustainability won out and I chose to join the walking tour in Crestone to avoid driving and to get some more exercise.

We met our tour leader, Jeremiah, at Crestone’s Town Park and hiked the few blocks to visit Carmin’s passive solar strawbale home. I remember going over her evolving plans several times with her as she approached the actual building phase. I’m sure that this planning has paid off for her, since there is very little that she would change about the house.

The passive solar aspect has been most rewarding, in that the average floor temperature during the winter has remained at 65 degrees F. This means that she only really needs supplemental heat during periods of gray days. In fact, she says that the upper clerestory windows provide too much direct sun in the winter, so she has added scrim cloth to soften the glare from these windows. One other thing she would do differently is to shed the roof towards the south instead of the north, so that the snow wouldn’t pile up so much, but would melt off instead.

A short hike through the woods brought us our next stop: Annie’s new strawbale yoga studio and home. Annie announced that the most sustainable aspect of her place is the location; she and her students can easily walk into town, which eliminates much driving.

First we inspected the yoga studio, a lovely, invitingly open space with floating bamboo floors and vaulted ceiling. There is a mechanical room that houses all of the equipment associated with her photovoltaic electrical system and the active solar water and space heating system, which serve both the home and the studio. Solar heated water is pumped through hydronic tubes embedded in the floors, and these heat the areas above them. The solar water heating panels on the roof of the studio have a drain-back arrangement to avoid freezing problems. Annie’s residence does have some passive solar heat gain, which is augmented by the adobe floors that act as thermal mass.
The PV panels are mounted on a pedestal south of the studio, and the rack can be manually repositioned seasonally to optimize their orientation. She has a net-metering arrangement with SLV Rural Electric, so that any excess electricity that is produced will actually run her meter backwards! For backup electricity, in case the power grid goes down, she has a battery bank, but this rarely gets used so she expects that batteries will last a very long time.

A short walk down the street brought us to the compound where both Jeremiah’s and Adam’s families live. They are proud of the work they have done on the property to advance various aspects of permaculture design, in terms of rain-water catchment and grey water reuse. There is a lovely pond that Jeremiah constructed that collects water that can be used for plants and livestock.

Adam’s house is nearly finished after several years of hard work. It is a hybrid structure, consisting of a central core cylinder of strawbale walls with appendages of wood-framed walls. The insulation for the wooden portions is sprayed soy-based foam. Much of the interior plaster is of earthen materials. There is an interestingly designed passive solar greenhouse attachment to the south. Adam admits that his lack of planning for his house has cost him some difficulties with lost time and money.

Just up the hill from Adam’s home is Jeremiah’s work-in-progress: a partially underground dwelling that he is building mostly on his own. He started out with having a large hole excavated with a backhoe. Then he carefully sifted through all of the excavated soil and threw the larger stones back into the hole. Next, he constructed a heavy timber-frame supported roof that is covered by thick EPDM waterproof membrane. Originally he was planning to turn this into a green roof, but later decided to fashion it for water catchment instead, so there will be a mat of gravel over the membrane to protect it and help filter the water.

The entire southern wall of the home is wood-framed for glass and passive solar heat. The rest of the walls are finished with stonework (using all of the stones that he threw in earlier) as infill between the wood posts. These walls are insulated on the outside with several inches of foam, and then protected with a moisture barrier before being backfilled. A room in the far back will serve as a cool pantry/storage area and the walls here were fashioned like those that the famous $50 underground house book advocates, with wooden slats attached to wooden posts, protected with plastic and then bermed with soil.

Jeremiah’s house is likely the most economical of all the houses we toured, since he claims that he will spend under $20,000 for the entire project. Being substantially underground and rather small, it will also likely be one of the most energy efficient homes.

It was threatening rain when we hurried over to Keith’s home, with Jeremiah leading the way on one of his ponies. This is another hand-made labor of love, with Keith doing most of the work. He is obviously a master at timber-frame construction, as the expansive vaulted cathedral ceilings proudly demonstrate.

Sandwiched between the massive timbers are thick, home-made structural insulated panels. The roof panels are a full foot thick, constructed of OSB skin with custom TGI ribs and partially soy-based foam (he has his own foaming machine). He claims that these panels provide R-65 insulation, while the thinner wall panels provide R-32. All of this insulation helps hold in the passive solar heat from the southern glass. Most of this glass is not protected from the summer sun with shaded overhangs, but with such a high vaulted interior, overheating in the summer may not be an issue…it was certainly comfortable inside the day we were there.

There is a full basement in this house, and some of this space is devoted to the equipment for regulating and distributing both the solar water and solar electric panels on the roof. The rusty color of the roof is intentional: he used tin-core metal roofing that is designed to provide a natural rusty coating, while keeping the metal from corroding all the way through.

As we left Keith’s impressive abode, the threatening rain was beginning to materialize, so I scurried along the side of the road to seek shelter in my waiting car. It was an afternoon well-spent, with much camaraderie and learning. I certainly have a better sense of the sustainable wonders that are harbored in unique Crestone.

Green Guidelines and Certification for your Home

noreply@blogger.com (Kelly Hart) — Tue, 21 Jul 2009 22:18:00 +0000

There are several ways for your home to meet guidelines or gain certification for certain standards for "green" qualities. The reasons for doing this vary. It might be that a particular certification will allow the home to qualify for special financing or participate in some desirable program. It might be that the certification will make the home more desirable for resale. Or it might simply be that this will prove that the home meets the high environmental standards of the builder or homeowner. I'll list below the most popular guidelines and certification programs that are available.

By far the most publicized and the most expensive certification program is LEED for homes. LEED stands for Leadership in Energy & Environmental Design, and is administered by the U.S. Green Building Council. Initially these standards were being applied solely to commercial buildings, but now they have transitioned to residential as well. LEED certification is most commonly sought by builders and contractors as a way to attract clients or qualify for specific programs. It requires a fair amount of detailed analysis and the inspection by a trained inspector. This can cost between $500 and $3000. What is being evaluated is the location and linkages, sustainable sites, energy and atmosphere, materials and resources, water efficiency, indoor environmental quality, and homeowner awareness.

The National Green Building Standard is a collaborative effort between the International Code Council (ICC) and National Association of Home Builders (NAHB). This book provides the "green" practices that can be incorporated into a variety of areas, from new homes to high-rise multifamily buildings, and from remodels and additions to hotels and motels. This standard outlines effective, relevant green practices, including lot design, preparation and development, resource, energy, and water efficiency, indoor environmental quality, and operation, maintenance, and building owner education. By defining four threshold levels of Bronze, Silver, Gold, and Emerald, the standard gives builders the means to achieve their sustainability goals – whether they are designing a basic, entry-level green building or aiming for the highest level sustainable "green" building with energy savings of 65 percent or higher.

The Energy Star Qualified Homes certification is administered by the U.S. EPA and the U.S. Dept. of Energy. Similar to the Energy Star rating system for home appliances, this certification is often employed by custom builders as well as production builders to enhance the desirability of their homes. The cost is that of a professional energy audit on the home. What is being checked is effective insulation, high performance windows, tight construction and ducts, efficient heating and cooling equipment, lighting and appliances.

The Green Building Guidelines were written by the Sustainable Buildings Industry Council. These guidelines read more like a textbook that discusses why, how, where and when to implement specific parameters. They deal with community and site planning, renewable energy, the building envelope, energy efficiency, water use, indoor environmental quality, materials, operation and maintenance. There are diagrams, pictures, and other resources, including checklists from some of the other green programs.

Health House guidelines, created by the American Lung Association, is actually a certification program. The objective of this is to assure that new homes do not adversely affect people's health. Specially trained builders pay attention to the site, building enclosure, finishes and furnishings, mechanical equipment, commissioning, construction hygiene, safety and health. The focus is on air quality, but efficiency is also considered.

The bottom line with all of these programs is that the homeowner will end up with a healthier, more energy-efficient, and durable home. And all of us will benefit from a cleaner environment.

The Cul-de-Sac Syndrome

noreply@blogger.com (Kelly Hart) — Tue, 14 Jul 2009 21:38:00 +0000

The Cul-de-Sac Syndrome: Turning Around the Unsustainable American Dream is a timely book that analyzes the origins and eventual failure of what has been known as the "American Dream." John F. Wasik, the author of this very well researched and written book is a finance columnist for Bloomberg News, so he has his finger on the pulse of American finance and folly. Published in 2009, The Cul-de-Sac Syndrome is full of insight about how the dream has become a nightmare and ways that we need to proceed so that we may sleep contentedly again.

Europeans began settling in the Americas with the dream of establishing private domains that would provide wealth and security. Thomas Jefferson popularized and manifested the "pursuit of happiness" through land ownership with establishing his grand Monticello in Virginia. He believed that all free men should have the opportunity to follow his lead and he imagined a huge grid of towns and farms extending across the continent. There would be lots of open space between individual homesteads, and each domain would be more or less autonomous.

If you fast forward to the twentieth century, you can see how Jefferson's dream became manifest in the movement of people out of cities' central districts to establish their own little Monticellos in the suburbs. Homeownership became a way of building and preserving wealth. Everybody could have, and was entitled to, his own little kingdom. The cul-de-sac syndrome was born.

Wasik outlines the history of how this simple impulse for a better life became a real estate mania, where leveraged debt became a tool for creating wealth through homeownership. The belief that real estate values only appreciate fueled a speculative frenzy that created one of the largest bubbles of overvalued commodities ever: homes. Tempted by mortgage companies with easily accessible loans, even people who obviously could not afford homes jumped on the bandwagon.

As we are so painfully aware now, the bubble suddenly burst in 2008, and the fallout from this will be felt for years. The author uses case histories of real people to demonstrate just how difficult these post-bubble times have been.

John Wasik doesn't stop the narrative with his description of how unsustainable the real estate bubble was. He discusses what is probably even more important: how unsustainable the homes themselves are in terms of design, placement within the infrastructure, and energy consumption. He shows how these factors are adding to the misery of homeowners who cannot afford to pay to heat and cool their mini mansions, nor can they afford the necessary commute to work. The cost of these energy inputs (largely from fossil fuels) is stifling both the consumer and the earth's biosphere.

In general the infrastructure that supports suburban development is not borne directly by the inhabitants or the contractors who built them; these costs are passed on to government agencies. So this is another way that such sprawl is economically unsustainable.

The cul-de-sac syndrome is negatively affecting our health, productivity, and family life. All of those hours spent driving is lost time that could have been spent walking or getting exercise, doing productive work, or having a good time with the family.

As an antidote to all of this malaise, the author outlines a variety of strategies. He describes how houses can be built to heat and cool themselves through passive solar design and how they can even produce their own electricity. Water can be conserved in many ways. And often these greener homes are healthier to live in because attention is given to possibly toxic materials.

Wasik sees green manufactured housing as a strong component of sustainable development, and he gives examples of these. He points out that factory-built homes generally waste less material, can be constructed faster, and are designed with proven efficiency.

One aspect of home building that I feel is largely neglected in this book, and in much of the "green" building trade, is any discussion of the embodied energy inherent in both conventional and manufactured housing. From an environmental standpoint this is a significant factor, in that all of the energy that goes into manufacturing industrial products for home construction, and transporting them to the site is a form of pollution. I would like to see greater recognition that natural building techniques and materials, such as adobe, rammed earth, cordwood, strawbale, and earthbag building have an important place in designing a sustainable future.

A major thrust of any movement toward a sustainable residential complex is the recognition that inner city, urban dwelling is considerably greener than living in the suburbs outside the city's core. Wasik shows that not only are people finding that they save money by being able to walk or take mass transit, but they are healthier and more productive because they are not spending that time commuting. It is a high priority for cities to examine their zoning and building codes to accommodate more dense urban and greener residential development.

So the new American Dream may take awhile to realize, but once we begin to attain it we will become more secure with a smaller carbon footprint, we will become healthier, and we will lead happier, more fulfilling lives. This new dream is less about each person having his own fiefdom and more about all of us coming together to realize a common dream of living in balance with nature on earth.

John Wasik has a blog where he explores many of the issues touched on in this article: dailywombat.blogspot.com and he also has a website: www.johnwasik.com You can find his book, The Cul-de-Sac Syndrome listed at Amazon.com.

Radio Interview with Kelly Hart

noreply@blogger.com (Kelly Hart) — Thu, 21 May 2009 22:11:00 +0000

In May of 2009, I was interviewed for nearly an hour by Veronica Entwistle for her “Paradigm Shifters” Radio Program, at www.bbsradio.com. Veronica and the station have been kind enough to allow you the opportunity of listening to some or all of this interview directly. Either the entire program, or specific aspects of sustainable architecture and natural building can be heard as individual segments. You can listen to all of this from this page. The topics covered in the interview include:

natural building
sustainable architecture
strawbale building
earthbag building
Earthships
passive solar heating
cost of natural building
papercrete
education
vernacular architecture
recycling building materials
underground building

Earthbag Slide Show

noreply@blogger.com (Kelly Hart) — Sun, 03 May 2009 15:50:00 +0000

The folks at www.naturalhomes.org have assembled a fun little slide show featuring images of earthbag projects around the world. If you click on one of the images it will take you to the source page.

Internet Radio Show Appearance

noreply@blogger.com (Kelly Hart) — Tue, 14 Apr 2009 18:04:00 +0000

I was a guest on an internet radio talk show Wednesday, April 15, 2009 in the afternoon, discussing topics related to green home building: http://truthbrigade.com/

If you miss the live show, it will be archived at http://recordings.talkshoe.com/TC-11887/TS-212923.mp3

I don't actually make my appearance on the show until about 20 minutes into it.

Toxic Drywall and the Ills of Modern Building

noreply@blogger.com (Kelly Hart) — Sun, 12 Apr 2009 16:38:00 +0000

I just read this article about the toxic effects of new houses that used drywall material shipped from China to the US in the last few years. Many people are getting quite sick and can no longer live in these contaminated homes. Nobody quite understands exactly what the cause is, except that the suspect drywall seems to emit toxic sulfuric fumes, especially under hot and humid conditions. These fumes are so corrosive that they can turn copper pipes black. It is estimated that at least 100,000 homes are likely affected by this problem, many of them built during the height of the housing boom when domestic drywall material was harder to find.

Wow. What a devastating example of the imbalance that exists in our modern times. Contractors, wanting to provide more wealth for themselves and those buyers who expected to soon turn around and make a profit on the houses they bought, turned to Chinese producers of building products. To meet the demand the Chinese carelessly threw together raw materials that appeared to be safe enough to use and shipped them across the ocean to the eager market. Everybody was making money...so why not?

Compare this to a more wholesome, sustainable scenario, where only local, natural materials are used for building, and speculation is not driving the economy. This never would have happened.

Thousands of lives are being ruined by this situation, through loss of health and economic loss, paying for houses that cannot be safely lived in. What a double whammy! The author of the article assumed that these houses would eventually have to be torn down to deal with the problem; I doubt that this is true since it is quite possible to pull out all of the drywall and start over with that phase of the construction, which is actually one of the last stages of building. Still, the impact is enormous.

If anything is to be learned from this, it should be that we need to take a serious look at how we go about using resources and making money.

Natural Building in Korea

noreply@blogger.com (Kelly Hart) — Thu, 09 Apr 2009 15:16:00 +0000

Professor Sunny Cai, who teaches architectural design at a college in Beijing, China, sent me some wonderful photos of traditional earthen buildings he photographed while on a recent trip to Korea. Sunny is especially interested in various forms of rammed earth, so I presume that these mostly represent that form. The stone structure appears to have been mortared with earth.

Time to Learn about Natural Living

noreply@blogger.com (Kelly Hart) — Wed, 01 Apr 2009 20:52:00 +0000

We are fast approaching the prime season for learning how to live more sustainably. This summer there will be opportunities galore to take a workshop nearby that will give you hands-on experience and understanding of a wide range of topics.

I have assembled dozens of these workshop and training sessions at one convenient place: www.greenhomebuilding.com. They are listed chronologically with enough information to give you a sense of whether they might be appropriate for you. If you don't find something there, I have also listed many places that have on-going workshops throughout the year at www.greenhomebuilding.com/education.

There are workshops about renewable energy that feature training about photovoltaic, wind, and hydro electric generation. Solar hot water for domestic use is also covered.

The theory and practice of passive solar architecture is taught, along with household energy efficiency in general.

Water conservation techniques, waste water treatment, compost toilets, water systems, and permaculture, are all featured topics at various venues.

In the realm of "natural building" there are many workshops about cob, timber framing, earthbags, earthen plasters, strawbale, stone masonry, cordwood, and green roofs.

There is no better way to learn some of the basics of all of this than by actually trying it out with your own hands. You will soon discover whether a technique is something you would like to use for one of your own projects. And there is the fun of joining with other folks to help each other learn. The instructors are mostly professionals who have dedicated their lives to learning and teaching the various techniques.

If you don't have the time or inclination to participate in such workshops, then you might enjoy attending one of the many expos or conferences that are listed along with the workshops. Much can be learned from browsing the exhibits and sitting in on presentations.

However you do it, there is no better time than now to find out more about how you can become more sustainable in the ways that you live!

Green School Primer

noreply@blogger.com (Kelly Hart) — Sun, 22 Mar 2009 15:05:00 +0000

I was given a pre-release review copy of "Green School Primer: Lessons in Sustainability" published by the Images Publishing Group. At GreenHomeBuilding.com I am mainly concerned with residential architecture, but what better way to learn about the effectiveness of sustainable architectural principles than within a school building that was designed with this in mind?

I loaned my copy of the book to a friend, Vince Palermo, who is advising a small charter school in Colorado. It just so happens that they are in the process of coming up with a proposal for a new school building. Vince, a retired physician and renewable energy consultant, is well versed in what makes for good sustainable design. Here are his comments:

"This is an excellent book, and very timely -- both in content and production. First, the book quality is very good, well laid out and organized, with lots of very good representative pictures
illustrating various principles, and is has a quality binding. Though LPA Architects are one of the largest planning firms in California, the book was printed in Australia. The forward and jacket are written by the current president of the American Institute of Architecture and Dean of
North Carolina State College of Design, so it is strongly supported by an important professional in the business."

"The content looks to my appraisal to be very good and embraces the spectrum of Green, from energy to holistic planning, including the environment and approach to proper utilization and selection of materials. The book is focused on ten principles and presents them succinctly and clearly with supporting illustrations. It is not focused on the details of execution -- leaving that to the architects."

"There is only so much you can put in 143 pages. It has a chapter on rating, but interestingly does not pursue the ultimate in energy efficiency, looking more on the total picture of green, healthy, and functional. LPA has designed or modernized 200 schools in California, some illustrated in the book."

"In all, an impressive book! I particularly like it because this could not be published at a better time, when the Secretary of Education is supporting charter schools and has a big purse. This is a template for progressive thinking in school design."

Natural Building Bookstore

noreply@blogger.com (Kelly Hart) — Thu, 19 Mar 2009 15:41:00 +0000

Rosana, my ex-librarian wife, has taken the data from book sales at www.greenhomebuilding.com over the last four years to create a convenient book store that features the top 350 books from that list. These are grouped into several topics, so browsing is easy. You can check out this new book store at hartworks.com/naturalbuildingbooks.

The Most Popular Green Home Building Books

noreply@blogger.com (Kelly Hart) — Tue, 17 Feb 2009 19:45:00 +0000

I sell a lot of books from www.greenhomebuilding.com, mostly as affiliate links through Amazon.com. Out of curiosity my ex-librarian wife did a search through our sales records of the last four years and discovered some interesting trends. Our top seller was Earthbag Building: The Tools, Tricks and Techniques, and we averaged selling over 6 of these every month.

Close behind this is The Hand-Sculpted House: A Practical and Philosophical Guide to Building a Cob Cottage. Actually, books about building with cob are very popular, with two others showing up in the top 11 best sellers: Building With Cob: A Step-by-step Guide and The Cob Builders Handbook: You Can Hand-Sculpt Your Own Home. This makes cob building the single most popular topic!

General books about green building are also very popular, with Building Green: A Complete How-To Guide to Alternative Building Methods selling about 5 copies each month. The New Ecological Home: A Complete Guide to Green Building Options and The Good House Book: A Common-Sense Guide to Alternative Homebuilding were also in the top 15 best sellers.

Two books about underground and earth-sheltered construction made the top 25: Earth-Sheltered Houses: How to Build an Affordable Underground House and The Fifty Dollar and Up Underground House Book. Actually the first of these is more about cordwood building, so if you combine this with Cordwood Building: The State of the Art, author Rob Roy has two titles among the top 7 best sellers.

The Stonebuilder's Primer: A Step-By-Step Guide for Owner-Builders, The Solar House: Passive Heating and Cooling, and Earthship: How to Build Your Own, Vol. 1 all made the top 10 list, selling about 3 each month. Then, if you add to this The Tire House Book, which was also among the top 25, it is obvious that building with tires is a popular concept.

There were three books on the top 25 list about adobe and rammed earth building: Adobe: Build It Yourself, The Owner-Built Adobe House, and The Rammed Earth House: Revised Edition. This makes methods of using earth for construction extremely popular.

Strawbale building also had three titles in the top 25: Small Strawbale: Natural Homes, Projects & Designs, More Straw Bale Building: A Complete Guide to Designing and Building with Straw, and Serious Straw Bale: A Home Construction Guide for All Climates. Considering how popular strawbale building has become in the last decade this is not surprising.

There are two books about storing food in root cellars that made the top 25 list: Root Cellaring: Natural Cold Storage of Fruits & Vegetables and Build Your Own underground Root Cellar.

One of my favorite books, Home Work: Handbuilt Shelter, a book published by Lloyd Kahn which features the earthbag/papercrete house I built in Colorado along with many others, made the top 25 list.

The final book on the list is Ceramic Houses and Earth Architecture: How to Build Your Own, a book written over a decade ago by Nader Khalili of earthbag building fame.

It is gratifying to see the popularity of all of these books, and many others that didn't quite make the list, that feature various aspects of natural building and sustainable architecture. It bodes well for the future.

Sustainable Communities and For The Greener Good

noreply@blogger.com (Kelly Hart) — Wed, 11 Feb 2009 16:19:00 +0000

The National Building Museum’s website (www.nbm.org) has recently started offering videos and “Q&A Forums” after many of the lectures in their Sustainable Communities and For The Greener Good program series.

A few weeks after the event, the speakers’ answers to selected questions are posted online. Both of these lecture series address issues related to sustainable development, green architecture, government policy and more. Through these forums, people who can’t attend their programs still have a chance to interact with the experts -- and they open the audience up to, potentially, the entire world.

They recently completed their first Q&A, with developer Jonathan Rose, and are currently accepting questions for the editors of National Geographic and C about their “Sustainability Roundtable” presentation on global warming and its effects on the built environment. You can find links to both forums (and to upcoming ones as they become available) at www.nbm.org. The question window for the Sustainability Roundtable is open until February 24.

I watched the introductory portion of the "For The Greener Good" video, which includes a sobering presentation by Dennis Dimick, executive editor of National Geographic magazine. His slide show graphically demonstrates the effects of global warming. The following discussion between him and Robert Ivy, editor of Architectural Record magazine is worthwhile.

New National Green Building Standard

noreply@blogger.com (Kelly Hart) — Wed, 04 Feb 2009 15:37:00 +0000

The National Association of Home Builders (NAHB) in conjunction with the International Code Council (ICC) has developed a new National Green Building Standard. This has also been approved by the American National Standards Institute (ANSI), which is a first for this organization. This new Green Home Building Standard is similar to the LEED process for evaluating and certifying homes, but is probably less costly to perform. It does rely on independent inspections to verify claims that are made. These standards will help home buyers realize just how green the claims might be for any given home they might be considering to purchase.

You can take a look at the criteria for this new standard, and even proceed with evaluating any specific project, by visiting the NAHB Green Building Program website. I did this and plugged in data for the earthbag/papercrete home I built in Colorado a decade ago. It took about an hour to do this, and I am pleased to report that I garnered a gold rating in almost all of the categories.

To give you a better idea of what they are evaluating, I'll go through some of the specfics of what they are looking for.

Lot Design. Here they want to assure that the building site is chosen in such a way as to not overly disrupt the existing environment, or better, to provide infill rather than develop virgin land, or even possibly release previously impervious lot coverage or clean up something toxic. Points can also be gained by paying attention to solar orientation, storm water management, and water-efficient landscapping.

Resource Efficiency. The very first criteria here is maintaining a small footprint, although I was dissappointed that they don't even have a choice for building a one-bedroom home! The use of advanced framing techniques or panelized construction is awarded points. Frost protected shallow foundations, drained footings, and appropriate grading around foundations is encouraged. Covered entries and large roof overhangs, termite resistant construction and proper waterproofing and flashing are good. The use of recycled, renewable, and local materials, along with a life-cycle analysis for materials, can all gain points.

Energy Efficiency. Here they consider the type of heating system used. Other appliances, water heaters and lights are evaluated. Both solar heating and passive cooling are awarded points, as is the use renewable sources of electricity.

Water Efficiency. The use of water-efficient appliances, irrigation techniques, rainwater collection, wastewater reuse and compost toilets are all encouraged.

Indoor Environmental Quality. They like to see the use of direct-vented gas appliances, air filtration systems, and moisture/condensation control. One area where I think they missed the boat here is in not recognizing the value of breathable wall systems in maintaining indoor air quality.

Homeowner Education. This encourages builders or sellers to provide good documentation for homeowners in terms of the use of installed systems and general maintenance.

Global Concepts. This is primarly concerned with minimizing the use of low VOCs which pollute the air.

All in all I would say that this new standard for evaluating the "greeness" of buildings is a giant step in the right direction. Virtually all of the basic criteria for building green that I have been advocating for years at www.greenhomebuilding.com have been recognized to some extent.

Oil and electricity consumption is down in the U.S.

noreply@blogger.com (Kelly Hart) — Sat, 03 Jan 2009 17:06:00 +0000

I am very encouraged by recent under reported news about a significant drop in the consumption of electricity and oil in the United States this last year. In a November article in the Wall Street Journal it is explained that “an unexpected drop in U.S. electricity consumption has utility companies worried that the trend isn't a byproduct of the economic downturn, and could reflect a permanent shift in consumption that will require sweeping change in their industry.”

Apparently the demand for electricity has been increasing at a rate of 1%-2% annually for decades, but this last year various utility companies have reported a decline of between 3% and 9% across the country. This of course makes it difficult for the utilities to plan for future demand. While milder weather and economic slow-down obviously have their impact, some of this lessening demand must be attributed to a conscious desire on the public to curb energy use.

According to Index Mundi, the world-wide trend for electricity consumption has continued upward at a rate of nearly 3% over last year however, so we should not be too quick to congratulate ourselves as a species. Still the U.S. used nearly a quarter of all electricity generated in the world last year, so this figure would normally have been much higher.

Worldwide oil use, however, has actually declined by a quarter of a percent this year, and this trend is projected to continue in 2009. In the U.S. the decline has been 5.8% over last year. Some of this drop can be attributed to the fact that Americans have reduced the number of miles driven by 3.5% over the previous year, and this trend has continued despite the lower fuel costs lately.

A lot of the commentary about these declines is lamenting the fact that economies are faltering and projections for an upturn are bleak. I look at these trends as good news however. There is only one way to begin to address the much bleaker prospects of global warming and the loss of global resources, and that is to change to way we use energy and consume things in general…and that is beginning to happen. The cold fact is that economic reality drives much of what happens in the world, so while it is often hard to accept, in the end a slowing economy may be our salvation!

I think that Barack Obama’s idea for jump starting the US economy through investment in green industry, especially for energy, is wise. If jobs can be created while developing an infrastructure that is less dependent on fossil fuel and more reliant on renewable energy, then everyone worldwide will benefit.

Moving Toward Green Building Codes

noreply@blogger.com (Kelly Hart) — Wed, 10 Dec 2008 15:29:00 +0000

One of the most anticipated speakers at the recent Natural Building Colloquium in Santa Barbara, California, was David Eisenberg of the Development Center for Appropriate Technology (www.dcat.net). David and his associates are tireless advocates of incorporating sustainable principles into existing building codes. He is an eloquent speaker, who can motivate virtually any audience, from dusty natural builders to formal building department officials. He knows how to gain their empathy by appealing to their common humanity.

When is the best time to approach building officials about a specific project? David says “Once you have a good idea of what you want to do…they need information and time to process it.” Also, he suggests that you “find some other official who has already approved something similar, and they can become an advocate. When you talk to officials, find out what they are concerned about, so that you can address these concerns directly.”

Under the “alternative building provisions” of the codes, if the plan is stamped by a professional architect or engineer, then the authorities won’t change them, partly because they don’t want to be responsible.

“Vested industry interests tend to dominate the codes, because they come to all of the meetings where these things are decided.”

To further the cause of instituting sustainable building codes, David suggests that:
1. Builders do good quality work.
2.Applicants meet the need of building authorities to feel good about the safety of projects.
3. We improve public awareness through publicizing the sustainable building that is done.
4. We make an effort to develop good relationships with building officials.

As a model for a broader approach to incorporating sustainable codes into all land use issues, David suggests looking at what is being done at the Rocky Mountain Land Use Institute (www.law.du.edu). They have created a “Sustainable Community Development Code Reform” Initiative. The objectives of this initiative include:

* Identify key sustainability issues and find ways to address them in the land use regulatory process through new standards, incentives, and the elimination of barriers.
* Analyze how current approaches to zoning, such as performance and form-based systems, must evolve in order to promote sustainable communities.
* Explore the nexus between sustainable land use planning and regulation, drawing upon examples from progressive communities that have adopted sustainable land use provisions.
* Develop and Implement a sustainable zoning code framework.
* Educate end-users, including local officials, developers, citizens, and professionals in order to foster awareness of how communities move towards sustainability.
* Act as a catalyst to bring various disciplines together – from agriculture, health, design, planning, etc. to form a coalition to support and promote sustainable development codes.

David emphasizes that it is more important than ever to bring a broad range of disciplines together to fashion integrated concepts for developing a truly sustainable future. His organization can use all the help it can get to further these objectives.

Shaping Buildings for the Humid Tropics

noreply@blogger.com (Kelly Hart) — Tue, 18 Nov 2008 22:42:00 +0000

Shaping Buildings for the Humid Tropics: Cultures, Climate, and Materials by Patti Stouter, 2008, is a 28 page PDF document that describes how to use ventilation, shading, plantings and insulation to provide comfort in hot humid climates.

This is one of the best sources of information about building and living in these challenging regions that I have seen. Patti points out that simple, low-cost buildings can be cool, dry, and mold-free if they are carefully planned. She also discusses the cultural differences that might affect appropriate designs.

She shows how to catch breezes to make the inhabitants feel cooler and to keep the humidity from building up. How to best orient a house to avoid overheating and ways to use landscapping to enhance comfort in buildings is outlined.

"One of the most important goals is to build of 'lightweight and low heat-storing materials' so there won't be much heat radiated towards the inside. Traditional building materials like wood, grass, palm, and bamboo are cheaper as well as cooler than masonry. But because they rot easily or are eaten by insects, they must be used carefully. Natural materials can be used inside to provide sound or heat insulation. Sea grass, rice hulls, and coconut fibers don't absorb much humidity."

"Earth buildings last well when maintained, and are less subject to overheating and dampness than stone or concrete. Earth walls don't get hot or cool very quickly because earth insulates better than concrete. Heavy concrete walls in very humid areas become frequently damp from condensation, causing algae or mold growth. Solid earth walls will receive less condensation than concrete because they are less dense, and because they absorb more humidity."

Natural Building Colloquium, 2008

noreply@blogger.com (Kelly Hart) — Sun, 02 Nov 2008 22:38:00 +0000

I attended the Natural Building Colloquium held this year at the Orella Ranch overlooking the Pacific Ocean near Santa Barbara, California, at the end of October. What a magnificent setting this was to spend a fine week of connecting with fellow enthusiasts of the natural building movement. About 70 attendees shared our insights, stories, passions, songs, poetry, cooking, concerns, and labor. I came away with gratitude for the opportunity to interact with such caring people, and with a renewed sense of confidence that we will manage to help forge a sustainable future.

This year’s Colloquium was organized by the Natural Building Network (www.naturalbuildingnetwork.org) and was hosted by Gunner Tautrim, who represents the sixth generation of this family living on this land since 1866. The accommodations were primitive, with only a small kitchen as enclosed space; the rest of the facilities were rustic pit privies, temporary solar shower stalls, temporary bamboo and tarp meeting spaces, and a nice lawn area. We brought tents for sleeping. All of this was happening with the grandeur of the Pacific coast as a backdrop, and the elemental simplicity and beauty combined to create an appropriate mood for contemplating the benefits of building naturally. After breakfast each morning we would gather in a big circle on the lawn to review the various options for the rest of the day and share other thoughts. Typically the mornings were devoted to work on a sturdy, permanent, multi-stalled toilet facility that was already framed with wood. Gunner wanted the walls and a surrounding fence to be finished with natural materials, and there were many volunteers who formed teams to accomplish this. Mostly, split bamboo or recycled fencing was used for a framework, over which cob and clay finishes were applied.

Lunchtime often featured tables where specific discussions would occur, having spontaneously been announced at the morning circle. The afternoons were reserved for many concurrent presentations or discussions, so there were always hard choices to make about what to attend. During the course of the week, over forty different topics were explored, in a variety of meeting places. These ranged from the use of materials (such as bamboo, cob, adobe, and lime) to more theoretical discussions about engineering, thermal properties, efficiency, and design. One of the most popular forums was about codes and ways of improving the acceptance of natural building techniques by building officials. I will be writing about this topic in more detail in a future blog post.

I shared one two-hour presentation about earthbag building around the world with a woman architect from Israel, who had brought plans for an earthbag residence that she was designing for a client there. First I talked about the history and development of this technique, and then profiled a number of projects that have been completed (see www.earthbagbuilding.com). After this introduction, the architect laid her plans on a table and we all discussed specific questions that she had about them. This was a great way to learn some of the basics of earthbag building, and then apply these concepts to a specific situation.
I was very pleased that a discussion was convened to explore the role that natural building can play in what was described as the “long emergency,” or the compounded effects of climate change, peak oil and other resource depletion, population pressures, and financial crises. Without this discussion I would have felt that we were negligent in addressing these most pressing issues. I plan to write another entire blog post about this.

After dinner (which was always delicious and usually vegetarian), we were treated to a variety of programs or entertainment that emanated from our group. Mostly these were slide or Power Point presentations, but one night was devoted to a talent show with lots of music and some stand-up comedy…great fun. I showed lots of pictures I took when in Jeddah, Saudi Arabia a couple of years ago where I had been invited to discuss sustainable architecture with the faculty and students at the King’s University (see www.greenhomebuilding.com/weblog for my essay about the situation there) .

One morning, about half of us opted to attend a tour of historic adobe buildings in the heart of Santa Barbara. The earliest remnants date to the 1780’s when Spain authorized the construction of a presidio and the Santa Barbara Mission. Much of this early adobe construction was toppled during subsequent earthquakes, but recent reconstruction, using stabilized adobes, has returned the area to its original presence. I chatted (in Spanish) with the Guatemalan and Mexican crew who were making new adobe blocks for further repair work. On the return trip to the Orella Ranch, several of us made a detour to the nearby beach to dip our feet in the ocean.

One of the delights of this event was the participation of James from Zimbabwe, Africa. This very engaging fellow brought with him pictures of a lovely little thatched cob circular building that he and some friends had made. He also brought his large thumb piano to serenade us with African ballads. This was a reminder of the deep roots that natural building has from all corners of the world.

All together this week of camping out in this spectacular place and connecting with these dedicated and compassionate souls has left me feeling heartened that we will find ways to overcome the enormous obstacles that lay ahead.

On a very foggy night before we were to disperse the next morning, during our closing ceremony, we arranged ourselves in two large circles that faced each other. We (on the outer circle) were asked to assume the role of addressing our ancestors (on the inner circle) from some indefinite time in the future. When I did this I felt strangely like I was really speaking from the future. I told the young woman who was sitting across from me that I did not blame her for the difficulties that she and subsequent generations had endured. I said that the pattern was innocently established well before she was born. Industrialization was fashioned to improve life, not deteriorate it, and the consequences were not foreseen. And then I told her how much I appreciated the hard work she was doing to address and correct the mistakes of our ancestors. I said that because of the actions of her generation, we in the future were enjoying a simple and healthy life based on ecological balance, and that we owe her and many of her generation our gratitude for all that they did to make this possible. We then stood and embraced, the Future and the Present, for a moment of true compassion.

To see more of my pictures taken at this event go to flickr.com/photos/kellyhart.

Earthbags Gone Wild in the Philippines!

noreply@blogger.com (Kelly Hart) — Thu, 18 Sep 2008 18:55:00 +0000

Mainly through the efforts of Illiac Diaz, a charismatic entrepenuer/actor/model/athlete, the Philippines has been home to some very innovative public works utilizing earthbags. Illiac discovered the benefits of this technology several years ago at Nader Khaili’s CalEarth Institute in Hesperia, California, and has been promoting earthbag building in the Philippines ever since.

Diaz is the Executive Director of My Shelter Foundation which has collaborated with various other governmental and industrial organizations to build new schools and clinics throughout the Philippines. He is quick to point out the many economic and sustainable advantages of this method of building, since the main component is abundant and natural earth. In hurricane-prone areas, such as the Philippines, earthbag buildings can withstand the ravages of nature better than most other systems. And with thicker walls, they are more thermally stable.

Here are several pages where you can find out more about the humanitarian works of Illiac Diaz: earthbagbuilding.com/articles/filipino, earthbagbuilding.com/projects/school, earthbagbuilding.com/projects/clinic.

The Billboard Earthbag Project

noreply@blogger.com (Kelly Hart) — Tue, 02 Sep 2008 16:31:00 +0000

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

noreply@blogger.com (Kelly Hart) — Tue, 26 Aug 2008 18:28:00 +0000

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

noreply@blogger.com (Kelly Hart) — Tue, 12 Aug 2008 17:39:00 +0000

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.