Site News
Greenhomebuilding.com has been averaging about 350 visitors a day, with about 11,000 people logging on during July. This has been the highest volume of traffic since the site was launched in February of 2002. Aside from from keeping the News and Workshops page current, and occasionally updated the questions and answers sections of various pages, there have been few changes to the site during the last month. I do have plans for some additions in the near future, including a page about sharing facilities, such as with cohousing communities, and another page about using bamboo to build with. I'll keep you posted about these developments as they occur.

Earth's population will be forced to colonize two planets equal to the Earth within 50 years if natural resources continue to be exploited at the current rate, according to a report released by the World Wildlife Fund. The Living Planet report uses an index to illustrate the shocking level of deterioration in the world's forests as well as marine and freshwater ecosystems. Using 1970 as a baseline year and giving it a value of 100, the index has dropped to a new low of around 65 in the space of a single generation. Based on factors such as a nation's consumption of grain, fish, wood and fresh water along with its emissions of carbon dioxide from industry and cars, the report provides an ecological 'footprint' for each country by showing how much land is required to support each resident. America's consumption 'footprint' is 12.2 hectares per person compared to Western Europe's 6.29 hectares. In Ethiopia the figure is 2 hectares, falling to just half a hectare for Burundi, the country that consumes the least resources.

Large portions of Alaska are melting and not far from Anchorage, a four-million-acre spruce forest has been killed by beetles. It is believed to be the largest loss of trees to insects ever recorded in North America. Scientists have tied the event to rising temperatures, which allow the beetles to reproduce at twice their normal rate. A Bush administration report has acknowledged that the burning of fossil fuels was the primary cause of the recent warming of the planet. President Bush (who has distanced himself from this report) wants to rely mostly on voluntary efforts to reduce greenhouse gas emissions. Under the president's strategy, it's estimated that emissions will actually increase over the next decade.

More than a million homes worldwide, mainly in villages in developing countries, now get their electricity from solar panels. If micro-credit financing is arranged, the monthly payment for photovoltaic systems is often comparable to what a family would spend on candles or kerosene for lamps. After the loan is paid off, typically in two to four years, the family obtains free electricity for the remainder of the system's life.The replacement of a kerosene lamp with a 40-watt solar module eliminates up to 106 kilograms of carbon emissions a year. Even in the UK, a cloudy country, putting modern PV technology on all suitable roofs would generate more electricity than the nation consumes in a year. This would eliminate all greenhouse gas emissions from nationwide electricity generation, removing almost 200 million tons of carbon dioxide annually from the atmosphere.

I generally try to avoid the use of cement as much as possible, because its manufacture produces considerable greenhouse gas emission. Some building technologies use Portland cement quite sparingly to achieve very durable building shells or plasters. I have used papercrete, which utilizes a small amount of cement to bind the paper fibers and mineral content into a very useful product. Ferrocement also has the potential to create a building shell with a relatively small amount of cement because the shell can be so thin. This technology has been used for many years in the boat-building industry to create surprisingly light-weight and durable hulls. With the use of several layers of metal lath and the careful application of the cement/sand/water mix, a shell can be created that is only half an inch thick! Once the cement has cured, it can be insulated with other materials or even buried with soil to take advantage of the buffering effect of the earth.

Ferrocement can also be used to make water storage tanks. In this case the cement can be rendered waterproof by carefully regulating the water to cement and cement to sand ratios. If the water to cement powder ratio is kept between .4 and 1.0, and the cement to sand ratio is around .5 (these measures are by weight), then the mix should render a waterproof product.

For more information about ferrorcement you might like to visit www.ferrocement.net , where you will find articles, a forum, a gallery of ferrocement projects, and a very nifty hand-held sprayer for sale. I had a chance to examine this sprayer personally, and I would say that it is very well made, and could likely be used for many application beyond the spaying of ferrocement; I imagine that it would also spray papercrete, lime plaster, mud plasters, etc. The hopper can be dipped into the material to be sprayed, and then compressed air is supplied to the end of the handle to force the material out of a series of large holes in the hopper...very simple, easy to clean, and no nozzles to get clogged.

Site of the Month
This month's featured website is www.caneloproject.com where you can enjoy an introduction to the work of Athena and Bill Steen, authors of the much respected book, "The Straw Bale House," and other fine media, mostly about straw bale building. This very attractive site not only describes this media, but takes you on a tour of some of the building projects that they have been involved with. In their own words, "We explore ways of living that connect us to others and the natural world. We seek to balance the wisdom and skills of the past with those things which have value today. We combine our efforts with others to creates simple, comfortable shelter using local and natural materials with handcrafted care."

Bill and Athena have a special affinity with Mexico, where many of their projects originate. They have assisted a group of women to create their own homes with straw bales. After they finished the project, one of the women said, "You know I always thought to have something this beautiful you had to have a lot of money. But now I know you don't. You just have to be willing to work for it."

More recently, the Steens have been involved with dome and vault construction in Mexico, using light-weight straw/clay blocks. Largely based on the work of Hassan Fathey, such buildings can be made without the use of elaborate forms by simply stacking the blocks in certain patterns. These buildings can be very inexpensive, durable, comfortable, and beautiful. The straw/clay combination produces a more insulated, lighter block than standard adobe.

Book of the Month

While we're on the topic of the Steens, I thought I'd review their first straw bale book, The Straw Bale House, which they co-wrote with David Bainbridge, and was published in 1994 by Chelsea Green. This is one of the most thorough, well written, beautifully illustrated and laid out books I've ever seen on any natural building topic. I'm sure it is one of the reasons why straw bale building has become so popular in various parts of the U.S.

This book begins with a historical overview, discusses common concerns that people have about straw buildings, and then goes into considerable detail documenting the entire process of building with straw: how to choose and store the bales, the merits of various systems for actually building the walls, how to create doors and windows, what types is foundations can be used, various roof possibilities, suggestions for floors, interior walls, electrical and plumbing, and how to plaster and finish the walls. All of this is covered with loving attention to the details that make it possible to actually go out and start your own project.

The final chapters deal with patio walls and other exterior uses, as well as house design considerations, including a discussion of the fundamentals of passive solar design. A resource guide, bibliography and index complete this hefty book of nearly 300 pages. There are many books available about building with straw, but I doubt that any surpass this one in aesthetic or educational value.

As I mentioned in my last E-zine, I am building a hybrid workshop/garage building, using earthbags filled with crushed volcanic rock, covered with papercrete to protect the bags and to match my house. The upper part of this building utilizes a prefabricated steel quonset structure which will act as a form to create the vault of earthbags and also to be the interior finish for the upper part of the building. The building process was slowed down by a nasty stub of my toe, but I am back to work on it now.

As you can see from the photo, I have begun assembling the quonset which is resting on the double rows of earthbags. At the point of connection between the bags and the steel is a buffer of 2X10 wood with steel angle brackets to which the steel ribs are bolted. Once this wood gets embedded with the bags going over the vault and eventually papercreted, the whole thing will become rather monolithic. The wood is also pinned to the bags with half inch rebar to further anchor the quonset. To make the whole thing more rigid and to be able to support the weight of the bags, there will be either cables or wooden floor joists for the loft tying both sides of the vault to each other at the point where the arc begins (the spring line).

So far I am pleased with how it is all coming together. I raised the first section of the quonset by myself on a day that was windier than I liked, by stretching a rope between the two trees and running a cable from the top of the roof section through a pulley on the rope, and then winching the section to a vertical position. Writing this is much easier than it actually was, because the steel was much less rigid than I expected and was sort of flopping around as I tried to raise it. I really should have had a couple of assistants guiding it up on either side, but I persevered I finally got the thing to stand on its own. Once I got it bolted and tied down, it was relatively stable. The second section was erected one piece at a time (each section is composed of five pieces). Now the vault is sturdy enough for me to climb around on it with confidence.