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.

Urban Green Building

I recently received two emailed questions about the seeming lack of attention to green building in urban settings:

"I happened to notice that very little, if not at all, mention of urban dwellings and how small urban homes are practically the greenest you can get when you factor in transportation. Green homes spread out in the country, unless you're living off the earth and have no use for a car, may counteract your carbon footprint savings if you have to drive on a continuous basis. A vast majority of Americans live in a metropolitan area, it would be nice if your information can include an aspect to the benefits of small homes in urban dwellings."

"I am curious about building an earth covered or underground home in the future. Can these houses be built on a small lot within a city? I think being close to your neighbors etc., is one way to help achieve sustainable living, however, the green homes I have seen always appear to be on a large parcel of land."

I think these folks are absolutely right about this. It is unfortunate that most of the natural building movement has been more of a rural activity...but there is no reason why it has to be. Virtually all of the principles of sustainable architecture that I outline at http://greenhomebuilding.com/sustainable_architecture.htm would equally apply in an urban setting.

In districts where housing goes above 2 or 3 stories, it is difficult to use some of the more natural techniques. One problem is that many of these methods of building result in rather thick walls, especially when the walls must go quite high, so that interior space is compromised by this. This is where some hybrid concepts might be useful, such as building with a steel framework to allow multiple stories, and then fill in the walls with less industrial materials, such as strawbales, cordwood, or earthbags.

As for going underground in a city, it certainly can be done. It would be a great way to create dwelling space and reserve most of the land above for gardening or parks, creating much needed green space in the city.

Also much of the movement towards "sharing facilities," such as co-housing, can be done in cities. This is another way to create both denser housing and reserve open space for parks and gardening.

I think that all proponents of green architecture need to put more creative thought into urban design!

Timber Framing

When I initially designed www.greenhomebuilding.com I intentionally avoided advocating the use of much wood in building, because of my concern for the health of our forests and their ecosystems, with all of the over-harvesting of timber that has occurred around the globe. There is also the fact that forests help sequester CO2 (a greenhouse gas) from the atmosphere.

This was a difficult choice for me, since my father was a wood worker and I grew up learning many of these skills; I love working with wood and I worked for years as a carpenter. It is certainly one of the most versatile of all building materials, and is a renewable resource, when harvested sensibly.

I have finally come to realize that building with wood (at least partially) can still be a sound ecological choice, which is particularly true in regions where forests have regenerated to the point that they can be harvested sustainably. This means that the trees are carefully monitored to make sure that the health and character of the forest is maintained; only certain trees are culled periodically, leaving the remaining trees to grow and contribute to a healthy ecosystem. It is possible to buy wood that has been certified by the Forest Stewardship Council (FSC), but if this means that you are buying wood shipped great distances, then this becomes a less ecological choice; use local materials!

Furthermore, with timber framing it is possible to use large wooden posts and beams in such a way as to create strong and versatile load-bearing structures, which can then be completed by either in-filling between the wooden structural members, or completely wrapping the timber frame structure with a variety of other materials (as is recommended in colder climates). Since this method of building has been recognized and approved by most code authorities, it is a way of approaching a natural building project that would otherwise be difficult for the authorities to sanction.

So I have now created a page about Timber Framing, greenhomebuilding.com/timber, with lots of media resources and informative links listed. I have also enlisted the gracious assistance of a preeminent timber framing specialist to answer questions from the public about this ancient art.

Will Beemer is a charter member and co-Executive Director of the Timber Framers Guild, and is owner of the Heartwood School for the Homebuilding Crafts in Washington, MA. For over 30 years, this school has been offering students a chance to improve their woodworking and timber framing skills. Will helps teach many courses at Heartwood and has been designing and building houses for over 35 years. He was a construction foreman at the Arcosanti project in Arizona, and design instructor at Cornell University. He has organized and taught building workshops around the world, including timber framing courses through the Guild and at Palomar College in San Diego, the North House Folk School and at the Colorado State University Mountain Campus. He has written for Fine Homebuilding, Joiner's Quarterly, and Timber Framing magazines.

You are invited to visit the new page about Timber Framing and to seek guidance about this art from Will Beemer.

Natural Building Network

There is a fantastic on-line resource for all people interested in natural building: www.naturalbuildingnetwork.org. This site was initiated in 2005 by a group of people who collectively have considerable experience in the realm of natural building, which they define as "any building system which places the highest value on social and environmental sustainability. It assumes the need to minimize the environmental impact of our housing and other supporting systems while providing healthy, beautiful, comfortable and spiritually uplifting homes for everyone."

The Natural Building Network is a non-profit membership association, where the joining members can place listings for their services and talents and network world-wide. Towards this end, there are directories of natural builders by location, by specialty, and by their willingness to teach others their skills. This helps the members find suitable employment and helps the public find experienced builders who live in their area. Additionally there are classified listings of announcements about related matters. The Network website also features listings of workshops and events around the world, along with resources for further education.

This network and website offer a much-needed central facility for collecting information about natural builders around the world.

Nader Khalili Died

The Father of Earthbag Building, Nader Khalili, died peacefully, surrounded by his family, a couple of days ago. He was 71 years old.

Here is part of a letter sent out by his family to former students:

“The flames that ignited him in life and the quest that brought each of you to Cal-Earth to learn from him have touched all of us and led us on this path….the right path……. for arts, humanity and the environment. His work and words have inspired us and his spirit is powerfully alive in every work and word, building and echo that your enthusiastic and loving hands have helped to create for this world.

His soul imbues every grain of sand and every memory contained in Cal-Earth, which expresses so much of his personal life of the last 17 years. And your works, like seeds have been growing and flourishing in every corner of the world…”

Born as an Iranian, Nader lived most of his life in the United States, gaining an architectural degree. He worked on the design of high-rise buildings and taught architecture in Southern California. In 1991 he founded Cal-Earth (the California Institute of Earth Art and Architecture) based in the desert region of Hesperia , California. From this center, he taught classes and workshops on the use of both bricks and bags to fashion domes, arches, vaults, and irregular shapes. These forms sprang from his early exposure to Middle Eastern architecture.

The earthbag concept evolved from attending a 1984 NASA symposium for brainstorming ways to build shelters on the moon. He realized that bags filled with lunar “dirt” could be stacked into domes or vaults to provide shelter. This concept was later refined to include stretching barbed wire between the courses of bags to help stabilize the structure. Nader never referred to this building technique as earthbag building; he preferred to call it “Super Adobe,” referring to the fact that he generally filled the bags (or long tubes) with an adobe soil mix.

In 1999 Nader was issued a U.S. Patent for his Super Adobe technique and he subsequently tried to require contractual arrangements for its use. At this point, however, he had been publicizing the idea for so long it was not an enforcable patent, and few would comply with his request.

This fact points to the complex nature of Nader’s personality. He truly loved humanity and the arts, and was an eloquent and passionate speaker. He often said that his ideas were a gift to humanity and he hoped they would provide shelter for the poor and disadvantaged. At the same time, he wanted to control the economic potential of his invention, and he pursued this vigorously.

Nader was the author of several books, including Ceramic Houses and Earth Architecture: How to Build Your Own, about literally making ceramic houses, and Sidewalks on the Moon, an autobiography. He also wrote several books about the the mystic poetry of Rumi. Interestingly, he never really wrote a book about his Super Adobe invention, allowing others to take the lead in doing this.

With the passing of Nader Khalili we have come to a point where his ideas and work can truly become universal. All of us who explore the potential of the earthbag concept and expand on its possibilities can help further his vision for bettering the world. We owe a great debt to this truly inspired individual. May he rest in peace!

Earthbag Tube Forming Machine

I recently got an email from Steve Cameron with the sketch shown below that he had drawn of a concept for filling and forming earthbag tubing into a uniform rectangular form on the wall being built.

Steve asked for any comments that I might have about this idea, so I wrote:

This is certainly an interesting idea, and a great drawing! I think that I understand your concept pretty well from the sketch. The squared bag shape would only retain that shape if the contents were solidified, as would happen with a soil/cement mix (which you specify); looser material would eventually force the bags into their more natural oval shape after the form were removed.

But then, I wonder, why bother with using the bag material at all? What you describe is pretty classic rammed earth with lifted forms, and there would be better adhesion with rammed earth directly upon rammed earth rather than with the bag material intervening.

If the purpose for forming the earthbags this way is mainly to reduce the work and material in plastering, I have to say that I don’t find the standard approach objectionable. All those crevasses between the bags give the plaster much better “tooth” than a smooth wall would, so there is an advantage to leaving these voids.

I should add, though, that the apparatus and concept is very clever, and shows great inventiveness; I suspect that it would actually function quite well as drawn.

I might mention that rammed earth is often formed with slip forms done in lifts of maybe 2 feet. The proper soil mix is 15-30% clay and the rest sand. Sometime a small amount (maybe 5%) of Portland cement is added as a stabilizer, but not always. This is one area where earthbags have an advantage, because you can get away with a larger variety of soil mixes.

Your suggested mix of 30% cement to 70% soil would be equivalent to a 3:7 mix of cement/sand concrete, which is very rich in cement! Standard soil cement mixes call for between 6 and 16% cement, depending on the specifics of the soil and the intended use.

Then Steve wrote back that the device was actually inspired by a photo he had seen on a site featuring the Natural Building Colloquium in Texas in 2007, which he redesigned to suit his own needs.

Global Warming Media

Every year I update all of the listings for media at www.greenhomebuilding.com and I am doing that now. Last year when I got to the topic of our environment and books about global warming I was astounded to notice that nearly half of the new titles were nay-sayers trying to cast doubt in the public perception of the issue. Most of these writers were associated with conservative think tanks or corporate interests.

As you might imagine there are many new books written about global warming and its consequences; I noticed over twenty five that were published in 2007. This time, the ratio of nay-sayers has diminished to about a quarter of the volume. I take this as an encouraging trend, in that the real science and public perception are obviously coming closer together. To see a listing of some of new media see this page.