Miscellaneous Questions about Sustainable Architecture

Kelly Hart is your host here at greenhomebuilding.com, and has been involved with green building concepts for much of his life. Kelly spent many years as a professional remodeler, during which time he became acquainted with many of the pitfalls of conventional construction. He has also worked in various fields of communication media, including still photography, cinematography, animation (he has a patent for a process for making animated films), video production and now website development. One of the more recent video programs that he produced is A Sampler of Alternative Homes: Approaching Sustainable Architecture, which explores a whole range of building concepts that are earth friendly. Kelly is knowledgeable about both simple design concepts and more complex technological aspects of home building that enhance sustainable living. He has even designed and built a solar-electric car that he drives around his neighborhood. Kelly, and his wife Rosana, live in the earthbag/papercrete home that is profiled on the earthbag page. He is available, at a modest fee, for consulting about sustainable building design, either for remodeling existing structures to more fully embrace these concepts, or for new architectural designs.

Questions and Answers

Q: May I ask you if you know if it exists rest houses (houses for elderly persons) built with respecting the principles of the éco-construction (I think you call it the green building) in your country or in other countries.

A: While I am not aware of any specific housing projects for the elderly that employ natural building techniques or principles of sustainable architecture, I suspect that they do exist. There is a growing awareness in the U.S. about the need to build in this more sensitive manner, and obviously the elderly or infirm might benefit even more from a healthy home environment.

Q: I am living in a single-wide trailer until I can build an alternative home. It has little insulation and winter here can get cold. Any suggestions for insulation? I need it to be inexpensive if possible.

A: I've seen people pile bales of straw up around trailers to help insulate them during the winter. It is not necessarily aesthetically pleasing, nor would they last very long (unless they are properly covered with a roof extension and plastered), but they are cheap, fast and effective.

Q: Do you know of any info and any studies concerning entrained energy in building materials?

A (Daniel Chiras): Yes, I do. There's a gentleman in New Zealand (Andrew Alcorn) at Victoria University in Wellington, New Zealand who has published a remarkable piece on embodied energy. You can obtain a copy by logging on to: arch.vuw.ac

Q: I got your email address from the greenhomebuilding.com Website. I've recently become very interested in natural building (all types really - cob, straw bale, bamboo, etc.), and I was thinking that I'd like to make a trip to various parts of the country looking at examples of existing naturally-built houses/structures. The only list I've really seen was for straw bale houses only. Do you have any idea how I might get a listing of places to go visit (including homes, if people are open to visitors)? The one place I've been to is the Real Goods Solar Living Center in Hopland, CA, and it really inspired me and made me want to travel around and see more examples.

A: I don't really know of such a list of homes open to visit. Occasionally alternative home tours are organized for specific events, such as a solar fair, but generally these places are private homes, and the owners need to be contacted individually. You might like to get a copy of the video I made called A Sampler of Alternative Homes, which profiles a variety natural building projects ( available at the STORE.) This video has a resource list inserted with some contact information of the people featured in the video.

Q: I am a high school student and I am doing a report about sustainable architecture. Is a sustainable house/building strong enough to hold any destruction or debris from any natural disaster?

A: This depends on just how the house is built, but it is possible to build a very strong house that would withstand most disasters sustainably.

Q: Have you considered employing traditional architecture since it is based on the use of natural materials?

A: I am a strong supporter of the use of vernacular architecture, and promote it at my website. The older ways of building usually employ the use of natural materials in appropriate ways. The wisdom of the past should be utilized today.

Q: What do you think about modern architecture, i.e. the façade and the employment of synthetic material in it?

A: Modern architecture generally leaves me feeling rather cold. The stark rectangular forms made from industrial materials does not relate to the natural world, and in this departure it attempts to isolate man from our Mother Earth. I am much more interested in being a part of the natural world.

Q: I am currently developing an exhibition at the Science Museum in London that will feature sustainable buildings. I have a question that I know has no definitive answer but it's one I have to ask. I was wondering if it might be possible to send an email round to all the experts to ask if they could name their top 3 sustainable buildings in the world? And if it they could give 3 reasons why, that would be fantastic.

A: As for myself, I would say that they would be:
1) My own house (viewable at http://www.greenhomebuilding.com/earthbag.htm#ourhouse ) mainly because it employs earthbag domes and a passive solar design that uses local natural materials.
2) Rob Roy's cordwood house, because I think that cordwood construction is one of the best ways to utilize scrap wood to create a wall system that is durable, low-maintenance, and well-insulated.
3) One of the basic Earthships designed by Michael Reynolds, because these employ many recycled materials in a configuration that provides most of the necessities for living in one integrated unit.

A: (Quentin Wilson) Taos Pueblo, New Mexico, Adobe. 900 years old. As mud falls off it is at the base of the wall for the next
maintenance cycle\ What is not repaired returned to the earth, oddly enough.

Potola, The Dali Lama's Summer Palace, Lhasa, Tibet, adobe, earth and stone set in earth mortar Can't tell where the cliffs end and the Palace begins. Totally local materials and labor. Sounds good when Paul Horn plays his flute there - good acoustics.

The Mosque in Dejenne, Mali, adobe Solid walls lead to solid prayers. As mud falls off it is at the base of the wall for the next maintenance cycle Vertical sticks protruding from exterior walls allow for easy scampering about when re-plastering.

A: (John Connell) Let's see. That's a tough one. I guess in the religious category I would give the Temple of Ise a vote. For residential, the Native Americans' "tee pee" along with most of the other nomadic structures of the indigenous people were beautifully worked out (even the igloos!). But in a more contemporary vein, I've yet to see a building that I think will still be impressive in 100 or 200 years. For me, that's the minimum test of sustainable structures. I do like Stone Hendge and most of what I see in Rome, Venice and Florence, but I think that's simply my western bias. I know there are older and more sublime examples of sustainable architecture in China and around the Pacific rim. I've always thought there was more to sustainability than saving energy and minimizing toxins.

A: (Leonard Jones) I'm not sure I can answer your question straight up... I'm not certain that sustainability is really an attainable goal, or just a dream... If we look back in history, we find that every human grouping (down to the village/tribe level) is a product of its particular situation. It may exist successfully for many years, but eventually the situation changes and the group must adapt to the new situation or cease to exist. Even with changes, the new situation may not be conducive to long term survival/sustainability. Finally, an examination of many cases reveals that too much success may be as harmful in the long run as failure.

There are enough historical examples out there to fill a library, but the best case I can point to in my area is the example of the Anasazi culture, who's people lived successfully in the mesa country of Colorado, New Mexico, Utah, and Arizona for several centuries. Then the culture suddenly failed and disappeared, for reasons that are still not clear. Studies on this case continue. Perhaps the future will shed more light on this and other similar cases.

As far as your request is concerned, I would nominate the Taos Pueblo near Taos New Mexico as one of the top three sustainable buildings in the world. Reasons: - It is the oldest still-lived-in building in North America. - It is made from highly sustainable materials... Mud, Straw, and local logs - The Taos climate is cold in the winter and relatively hot in the summer, but the Pueblo's passive solar heating capability make it possible for the occupants to live comfortably in the winter with only minor fuel consumption. Also, its thick mud walls make it cool and comfortable in the summer. - Until modern times, the occupants were able to live reasonably well using local land, water, and other resources in a sustainable way without exceeding the capacity of those resources. They were able to do this with little, if any, external resources...

A: (Owen Geiger) I suspect that most responses will lean towards high profile commercial structures that get featured in architecture magazines. However, I favor the approach of appreciating and recognizing humble structures that are very well made. I'm referring to small, simple homes built sustainably that often get little or no attention. This is significant because if tens of millions of people built in this way (which is possible if these type of houses were given more attention) many of our environmental and housing problems could be solved.

Q: I'm a student at Iowa Central Community College. I'm currently taking an Environmental Science: Alternative Environmental Solutions course. My final project of this class has to do with creating my own island in the Caribbean. I have to figure out types of housing for 2000 people over 2000sq.ft region. This island would be subject to hurricanes, harsh winds, variety of temperatures, and other weather issues. I wanted to know what the best type of earth home would be best for an all weather area, most economical and environmentally friendly and safe for people to live in. Also, information regarding cost / budgeting of supplies and where to obtain these supplies would be great.

A: From what you describe about your project, I would suggest that you consider earthbag building, since it can be practically indestructible, inexpensive, and very earth-friendly. You can read more about it here.

Q: I want to develop a community that is as affordable as possible, with as much GREEN going on as I can muster up, and, still make money. I was wanting to use ICF and solar panels. My thinking is the benefits of the structure, coupled with the solar energy will produce a home that people will see the benefits and want to own one of the homes.

A: It is true that people are attracted to well-built homes that utilize sustainable principles. You can read my thoughts about ICF's at here. Using solar panels for heating water or hydronic space heating systems makes a lot of sense...they work very well. Solar panels for electricity are also good, but they are expensive and don't always make sense if the bottom line is financial. Passive solar design makes the most sense of all. See this page for more about this.

Q: I work for an organization involved in environmental protection in Lagos Nigeria and we wish to build an environmentally friendly building in Lagos which is suitable for tropical conditions. I need advice about green buildings in tropical Africa and also would like to be put in contact with any 'green architects' in Lagos Nigeria or anybody interested in such a project.

A: (Owen Geiger) I suggest networking with local architects, architecture schools, builders, etc. You'll likely find craftsmen using age-old building techniques - thatchers, stone masons, etc. Search out building supply centers and suppliers of natural building materials (bamboo cultivators, for example). Research traditional building methods - adobe, stone, bamboo, thatch, etc. to learn what works best in Lagos. Study good examples of local architecture and take pictures. Find out what people really want the most. Try to utilize vernacular styles and typical room sizes as much as possible. Once you have a good idea of what is most appropriate there, then consider doing more detailed research on the Internet: For example, how to better preserve the bamboo; how to add reinforcing to make the buildings stronger; maybe start to cultivate superior bamboo from another country; incorporate appropriate technology such as fuel efficient and smokeless cooking stoves, solar ovens, rain water collection and purification systems, etc.

Q: I am very interested in unsustainable, natural building methods for a home I have designed and would like to build. As I go through the material on the different methods, however, it seems that most of the techniques lend themselves to warmer climates. I live in a coastal area of northern Maine where the frost line is about 4-6' and moisture levels can be high. The best siding material locally available is cedar shingles (some of which can be recycled according to a knowledgeable local builder). I don't see any method which would allow for the attachment of a shingle layer to protect the exterior surface from moisture. Another plus would have to be high insulation value. Would you have any suggestions. Have I missed something in some of the material?

A: Most aspects of building naturally and sustainably that are outlined on this website lend themselves to cold climates. This is especially true of passive solar designs, which perform well, even in areas that are compromised by many cloudy days in the winter. You are right that insulation is key in any area of extreme climate, so choosing a system that provides good insulation is essential. Your choice of materials should stem from several considerations: 

First of all the design of the house will dictate the sorts of materials that are appropriate for various parts of the house, for instance, strawbales or insulating earthbags might be appropriate for the north side, while wood framing would be more appropriate for the south part with more windows.

Second, choosing locally available materials, such as your cedar shingles, to be used where appropriate is another sustainable principle. But every building method requires careful analysis to create a wall system that will perform well over time. Some degree of breathability is usually desirable, but not always. You might want to discuss your project with some local green experts, so that the entire house will perform well and you will be happy.

Q: I am currently a junior at Snider High School in Fort Wayne, Indiana. I am planning on doing a science fair project this year on the effects of earthquakes on different types of buildings. I have done science fair projects in this area for the last two years. I have looked at your website and think that the material presented will really help me. I would like to build model buildings to test using my shaker table but was looking for some suggestions.

I was at your website looking at some of the Adobe and rammed dirt homes and wanted to try to build some model buildings of these types of homes to test with my biaxial shaker table. Any ideas you might have along this line would be very helpful. I am really interested in finding out how earthquakes damage third world home.

A: What you propose is excellent. I have forwarded your query to the experts in adobe and rammed earth construction for their comments. Earthen building has gotten a bad image around the world from the tremendous loss of life that has occurred from old building techniques that do not adequately protect inhabitants from earthquake damage. Newer building techniques are much safer. Good luck with the project.

Q: I want to build a "green" house near Johannesburg in South Africa. As green and as cheap and as pretty as possible. I have 6 1/2 acres, 4000 liters an hour borehole water, 2 & 3 phase electricity. Temps here vary from -2C in winter to +30 in summer. Sun for more than 300 days per year. Dry sunny winter. Wet sunny summer. Not much wind. SA has 7 million cars on the road. Thatch grass cheap. Who to talk to and how to start?

A: Sounds like you have a lot to work with, having all of that land, water, electricity and sun! I would suggest a passive solar design to take advantage of the sun during the cold season. For economy, I suggest that you use the local grid power rather that try to generate your own. Thatch makes an excellent roof, so use that. As for materials for the rest of the house, I suggest you browse the pages on natural building at Greenhomebuilding.com to see what might be available locally (perhaps on your land), economical, and appealing to you.

Q: I am an Architect living and working in Antigua, West Indies. I am currently in charge of designing many houses for rich clients who desire fairly large holiday villas and retreats on this tropical island. I am also designing several hotels and developments. I wish to be more environmentally friendly in my approach. At present, I employ a natural ventilation approach to combat the heat, which works very well in keeping the houses cool, but doesn't reduce the carbon emissions or electricity levels of the house that much. Please advise on the practicalities of solar and wind power, and any other methods of sustainable design in the tropics.

A: Both solar and wind generated electricity should be viable options in the tropics, as long as there is enough sun and wind to sustain these. Wind power usually requires rather consistent winds to be worth the cost of installing. Other aspects of sustainable design worth considering would be: compact design, passive solar heating (if heating is required), earth-sheltering to help moderate temperatures, water conservation measures, the use of local, natural materials (except wood, where this is rare), recycling building materials, incorporating grow spaces and naturally cool pantries into the design, and the use of cooperative housing, such as co-housing.

Q: I was wondering if you could offer some information as to websites or contacts for my building plans. I would like to build a very small cabin or cottage type structure on a lot I have in Maine. We would need to purchase the basic materials in a kit and have construction assistance for the basic shell. The structure would be approximately 24'x24'. My dad could build the inner structures. We need ideas for unconventional, environmentally sound, and most importantly the least expensive way to go to build such a structure. Thanks so much. I am building this for my dad and have a very small budget.

A: Finding a ecological kit home is not an easy proposition. Most kits are fairly conventional in materials and designs. There are quite a few domes and yurts that are available as kits, which you could find by googling. Another possibility might be using a steel quonset like I did for my Carriage House. A more ecological approach would be to construct the house from scratch using local, natural materials, such as cordwood, strawbales, adobes, etc.

Q: I'm 57 and have a degree in environmental science. The views expressed on your web site offer no real solution for the housing demand created by the current and projected increases in world population. (Whatever happened to the push for zero population growth?) None of the home building methods promoted here will produce homes fast enough and at an affordable cost to effectively meet the demand for urban settings. Have you considered any mass production methods? By mass production I'm suggesting 10 million homes per year? Humans are indigenous inhabitants of the world. They are not going away, in fact they are duplicating at a tremendous rate. The most serious negative environmental impacts occurs in urban environments. People are not going to voluntarily leave cities. What is your housing solution for urban environments? If you can solve this question you will have provided a true service to your subscribers.

A: I agree with you about the pressure that population increase places on all systems that attempt to be sustainable, and this is certainly true relative to housing. I don't think that there is any one solution to the mass production of urban housing at a sustainable level. It has to be approached bioregionally, utilizing those materials and techniques that are both available locally and culturally appropriate. Most of the natural building options listed at at this site can be used in urban settings, although high-rises generally require industrial materials. A greater emphasis needs to be placed on educating people about the risks we face with over-population, especially on a governmental and religious level. Better educated people usually reproduce less.

C: I'm not saying I've found the ultimate solution to environmentally friendly housing but I found an insulated concrete wall system that deserves consideration. As you know concrete requires a large amount of energy to produce.  Most of the energy is consumed during the firing of the calcium carbonate in the manufacture of cement.   The steel in the reinforcing bars "rebar" also consumes a great deal of energy. The pay back is in the 1,000 year design life.  Precast concrete elements used in the construction of the Coliseum in Rome are still intact today, nearly 2,000 years later.  If homes and multi tenant housing units were made of insulated concrete wall panels they would provide energy efficient shelter for people for hundreds of years.   The cost in energy and dollars when spread over a 1,000 year design life make this type of construction much less expensive than any other building material that I've found including rammed earth.  I would be surprised if a rammed earth house could last even 100 years without a great deal of maintenance.

R: Actually, earthen architecture is among the most enduring of all. The oldest buildings in Colorado are made of adobe; cob houses in England have been around for many centuries; the Great Wall of China is partly rammed earth...all of this with only a modicum of maintenance. It is mainly a matter of good design and attention to detail that keeps these viable over time. And then, if their useful lives come to an end, the structures will simple melt back into mother earth...no residual pollution. Concrete has its place, but for sustainability you can't beat the earth!

C: I agree that after a cursory examination of the facts, rammed earth appears to be more earth friendly than concrete, the problem is that rammed earth is very limited structurally.  The strength of rammed earth is around 800 psi. Pneumatically Impacted Stabilized Earth "Pise" walls that utilize cement as the stabilizer only reach 1,000 psi. This type of structure, without steel reinforcement, cannot be made strong enough to resist structural loading that occurs during a serious seismic event in structures that are over 2 or 3 stories. Concrete (5,000 psi) can be designed to reach 100+ stories, will stand in a seismic events of 8 on the Richter scale and is 100 % recyclable.  So after it's 1,000 year life will also find it's way back into structures that will last another 1,000 years. Rammed earth is far too labor intensive to be a viable method for building housing units in multiples of 1,000 or even 100. Populations are much more concentrated and the housing shortages more extreme in some Eastern countries where land is precious and the only way to build housing is vertically.  Rammed earth simply will not work in this situation. I hope you can convince me to accept other construction methods as superior to concrete for providing structures to house millions of people with the least impact on mother earth.  Until there is something better, I'm sticking with the gray stuff.

R: I agree that if you are going to go up over three stories, then steel and concrete is the only way to go.  I actually think that going the other direction makes more sense. Digging into the ground has so many advantages, I am surprised it is not done more often. In most locations I think it is the only way to achieve a truly zero energy home...and it can leave the surface of the earth available for plants and nature. Much of this underground building can be done with earthbags, so the cost environmentally and economically can be minimized. Obviously population density cannot be accommodated as readily as high-rise building, but if this is the only way to go, then I think we really better find ways to limit populations.

Q: The rammed earth constructions and natural building materials sound great for a sustainable development. Being an architect based in urban India where the density of population demands the construction of apartment buildings of at least 4 to 5 stories, how can these principles be adopted for this construction? What is the sustainable way out?

A: This is a tough question, and one that I have also referred to the rammed earth expert for an opinion. Generally residential building doesn't go beyond three stories, and one of these can be below grade. I know it is possible to go higher with many materials, but usually at the expense of loosing space to very thick walls. Earthen walls need to have an aspect ratio of at least 10:1, so a 10 meter tall building would have to be 1 meter thick at the base, which can then taper as you go up. Using natural tensile materials, such as bamboo, is another option if they are available. These can be bundled  and braced in ways that make very tall buildings possible. I would suggest that going underground makes a lot of sense to gain mores space and to buffer climatic extremes.

Q: What are your suggestions for building an adequate horse barn that will sustain high winds such as a tornado?

A: I would consider earthbags, since they are very sturdy under adverse weather conditions and are rather inexpensive and easy to build with. You can read more about these at this page. The safest would be to make a dome, or a series of domes. If you go with a conventional roof, then it needs to very substantially tied to the bag walls.

Q: I am currently a student at Parsons Art School of Design in New York City. I have been working for over a semester researching the tsunami. As a product design student I was assigned the subject of shelter for the tsunami in Thailand for our final. I have studied the area, climate, and existing shelter, but the problem that I found when trying to design shelter is that there is a deficiency of existing industrial products that could be transformed into housing, lack of natural materials such as bamboo, and costly mass production. Currently they have been forced to live in cloned tin huts that have an oven effect in their hot humid climate. These people will be economically challenged for years to come so I want to provided them with a book that states where natural resources can be found in that specific area and different styles of homes that can be made out of them. I know that there is plenty of sand in Thailand, and I have heard from a women who does work there that there is clay and limestone, but I am stuck because the houses in Thailand are raised for monsoon season. I thought it would be the perfect idea if the people could make and design their own homes out of free materials found in the earth but now I am coming across problems on how would one raise a cob home. If you would be so kind to email any information it would be greatly appreciated.

A: I appreciate the work you are doing to help the people stricken by the recent tsunami, and your interest in providing inexpensive, natural housing for them. We recently had a question about the appropriateness of adobe construction in Laos, where seasonal monsoon weather is also a concern, we have had advice both pro and con this sort of development. In general, people agree that with a good foundation, overhanging roof, and some stabilization of the lower portion of the walls, that this type of construction can withstand the weather.

Another approach, that I have personal experience with, is earthbag building. With this, you can fill the bags with whatever soil is available on-site, and create walls that are practically any shape, even domes that eliminate the need for much wood or steel in the building. You might look at this page for more about this, including reference materials to learn more: Earthbags . It would be possible to design a raised earthbag building, if a separate floor were build a meter or two above the ground, but of course this requires more expensive materials than just building on the ground.

Q: Are you familiar with Enertia.com? Have a look at their houses with a geothermal loop.

A: I have looked at this site before, and find this an interesting concept. Double envelope house designs have been around for several decades and they definitely offer some benefits, as well as raise some questions. Any house that takes advantage of the geothermal properties of the ground will be doing its inhabitants and the earth a good turn. This can take the form of earth-sheltering in general, or some clever system of circulating air like the Enertia concept; coupled with sensible passive solar design, it is possible to approach a "zero energy" home.

The concerns about their system that I have are: The use of wood as the primary building material is not generally sustainable in this day of lost forests. With the double envelope design, you are practically building two houses to end up with one. Relying on wood as a thermal mass material compromises the potential thermal performance because wood does not serve this function nearly as well as traditional masonry thermal mass materials. So, I guess what I am saying is that a more sustainable and less costly design can be accomplished in more traditional ways.

Q: The website does address your objections to the Enertia home -- they say that the wood they are using is very fast growing and is being replanted faster than they are using it, and that wood is massive and holds at a more comfortable temperature than stone or concrete. The issue of building double is something else. That leaves me with the question of whether to believe them or not -- I'm sure they are very enthusiastic about their own product, but does it merit it, objectively? I guess I'll have to find someone who has lived in both kinds of houses to compare them. Any ideas?

A: Talking to people who have experienced living in their designs would be good for feeling out the comfort level, which I would expect to be quite high. Evaluating the ecological aspects is a bit more difficult. I stick with my original observations.

Q: I am getting ready to build the first straw bale home in Los Angeles County, Ca. in the high desert city of Lancaster. It is relatively dry, though we do get our downpours. Thanks to our wonderful building dept. and city council we changed the local ordinance, and I actually have an approved set of plans. My question is re: a Landscape & Privacy Wall (or estate wall). It would be quite large. Almost a thousand linear feet by six feet tall. I have been thinking about straw bale or rammed earth, and am open to any other suggestions you have. What are your thoughts regarding Sustainability, cost, permitable, and durability?

A: People do make walls with strawbales, but I don't recommend it because of the potential for rot eventually. Rammed earth is certainly possible, but it takes a lot of heavy equipment and forms to do it. I would recommend earthbags for your project as a sustainable solution that is fairly easy to accomplish, durable, and uses just the earth on site, most likely.

Q: My brother and I are in the process of starting to build a couple of personal houses here in Utah, up in the mountains as well a potential project in southern California. The real issue lies with the homes in Utah. The climate here can be quite dramatic. From fall to spring, it snows and can be cold, rainy, etc. Are there any processes for designing a home in a cold region that differ than building a home in a warmer climate? I imagine that building green differs slightly here and will require much more attention to the climactic changes. I just would like to attain as much knowledge as possible about green building in more intense climates. Any direction you can lead me to will be most appreciated.

A: You are right that a well-designed home must take into account the particular climate of its site. In any climate of severe temperature changes, it is imperative that the house be well-insulated, so this must be considered in the design and material choices. In a climate with cold winters, the best way to heat the house is with a solar heating system, either passive or active. And then my third bit of advise is to seriously consider an earth-sheltered design, since this will radically diminish the amount of fuel needed in any season to keep the space comfortable.

An Interview with Loghomescabins.com

I came across this wonderful site that is all about green home building. Green building – if traditional building methods are followed – can be a very cheap way to build houses, so this site is of special interest for us back-to-the-nature log home builders, who might be discouraged by the high prices of modern log homes and log cabins. Kelly Hart has a long history in the field of construction and publishes information on green home building in cooperation with many experts of this field. Mr. Hart was happy to answer few questions, so here they are:

Q: Post and beam log building is mentioned here and there on your site, but always as a mere structural framework. Why Greenhomebuilding doesn’t include log homes as an independent segment?

A: This was a conscious decision on my part to not promote the use of logs for homes for several reasons. Primarily, I am concerned with the continued depletion of our forests, as expressed on my page about saving our forests. There are circumstances where logs for homes can be harvested sustainably, and I encourage this, but in general this is not the case. Another reason I don't promote the use of logs is that they really don't provide very good insulation as a shell for a home, and this is a very important factor in any climate with temperature extremes.

Q: You introduce several methods for greener building. Apart from earthbag building, which are your personal favorites?

A: Interestingly, one of my favorites is also wood, in the form of cordwood construction. I like this method of building because it uses very small pieces of wood (more or less firewood size) that can be arranged in such a way as to provide a very well-insulted wall. This means that a considerable portion of the tree can be used, and that very small diameter trees that result from thinning a forest can be used. When the cordwood is stacked with masonry or earthen mortar and an interior void for insulation, you end up with a wall that has wonderful thermal properties because the interior masonry acts as thermal mass. An added benefit is that once you build the wall there is no more finish work necessary, either inside or outside, and it is a very durable, low-maintenance system. Building cordwood walls is a technique that is easily learned, requiring little skill.

Q: It is often so that pioneers create future trends by working very hard on their dreams. Do you think that at some point these green home building methods that you introduce on your website, will become popular among commercial constructors and house buyers?

A: This is already happening, especially with strawbale construction, and to a lesser extent with rammed earth and adobe building. This movement gained momentum in the Southwestern United States and is now finding popularity in other regions of the world.

Q: Many readers of Log Homes Cabin are planning to buy a log home kit as their starting point for owner/builder home. How would you increase the greenness of such a home?

A: First of all, make sure that the logs for that kit have been harvested sustainably; check with the Forest Stewardship Council (http://www.fscus.org) about this. Then select a kit that is as compact as it reasonably can be to house your needs...extra space costs more, both economically and ecologically. Choose a design that will heat itself with passive solar, especially if you live where you have cold winters. And get one with the best insulation package possible, especially for the ceiling and roof where most of the heat loss is.

Q: My wife and I are considering investing in a residential development in Munnar, Kerala (India) which offers several models to choose from. We would like ours to be "green". We like the project and have met the developer/builder and are wondering now how to make our future "cottage" meet green standards in terms of materials, energy efficiency, etc without causing undo burden or cost increase. Have you some suggestions?

A: If the developer has several models to choose from, then most of the design and material choices have likely already been made. It is a fairly delicate balance between design, climate, and materials that determines how "green" your house might be. Without knowing many of these specifics it is difficult to suggest the best options. But if you have a list of materials, I can give some general suggestions about what my preferences would be.

Q: I notice that no insulation is used in India or double glaze windows in houses, but I came across a hollow block system that appeared in The Hindu a few weeks ago that can cut down heat transmission for patios over habitable space through the mechanics of moving air acting as a a thermal barrier and thought about using them for the roof and roof tiles over these blocks. I thought this would solve the problem of the radiant heat from the roof during the summer but is it worth it considering that the radiant heat is coming from the roof. I also thought a solar hot water heater and a few small photovoltaic cells for recharging a cell phone and laptop computer might be a good idea. I would like to hear what you think about these ideas and if you have used the hollow block system.

A: I would say that all of the ideas that you suggest here would be of good use. The bulk of heat transmission, both in and out of a house is through the roof, so insulation there is especially important. I am not familiar with the hollow blocks that may be available in India, but the common cinder blocks available in the US provide only partial insulation because there are frequent solid bridges of masonry that make them less effective. In some localities blocks of light-weight concrete are available that have some insulative qualities, so that might be another option.

Q: We are in the process of building a centre for the visual arts at Findhorn, Scotland. We would like to create a 'green' eco car park area, with bricks and grass, for example. Do you know where I can go to research info on how one would create this?

A: Paving a parking area with pavers or bricks that allow water to be reabsorbed into the soil is definitely preferable to solid pavement that is impervious. On the other hand, such bricks or pavers have a lot of embodied energy, so a greener approach might be to use ordinary gravel. I suggest doing a web search for specifics about installation, since I don't have any other sources to recommend.

Q: Hi Just want to know what you opinion is on Tin verses concrete barrel roofing. I live in Florida and they want to replace our roofs with tin ones.

A: I don't have at hand comparisons of the embodied energy represented in those two materials, but I suspect it is somewhat of a wash. "Tin" roofs can actually be made of a variety of metals and coatings, each with different costs, durability and thermal characteristics. An excellent article about these is at http://www.motherearthnews.com/DIY/1984_March_April/A_Few_Words_In_Defense_of_Tin_Roofs  . Much steel is recycled these days, so that is one consideration..even though the remanufacturing process is obviously energy intensive. Concrete tiles are very durable, but the manufacture of concrete creates pollution as well. Another factor here is the greater weight of concrete might mean beefing up the roof structure itself in order to support this sort of material.

Q: You must've researched all kinds of sustainable building materials for your " A Sampler of Alternative Homes" DVD. Yet, in the end, you chose to build your own home with earthbags and papercrete. Why?

A: Partly I chose to use earthbags because of their inherent flexibility; I filled some of the bags with the crushed volcanic stone (scoria) and some of the bags with the native sand. The other reason I used them is that they allowed me to build domes that eliminated much of the need for the use of wood (a scarce resource) and steel to build a roof.

I chose the papercrete partly out of curiosity to see how it would work as a plaster over the earthbags, and partly because it would provide more insulation for the shell of the house. Economics was also at play here, since both of these methods tend to be very inexpensive to utilize.

The combination of earthbags filled with scoria with a papercrete plaster proved to be a viable approach to building an inexpensive, yet thoroughly sustainable dwelling.

Q: I was wondering if you have any info on building a green home when the land you have a gully to work with. We live in King George Virginia where it gets cold in winter and hot in summer and a lot of rain. We don't have a south facing area to work with and have a lot of trees. Instead of having a hill that you can build into that's flat in the front we have a flat area at the drive, then straight down the hill into a gully. We don't want to remove any trees that are currently there because they are over 100 years old.

A: Ordinarily I don't advise anyone to build in a drainage area like you describe, but sometimes it is unavoidable. Rather than trying to fill in an area to build on, I would suggest that you consider building on a pier or pole foundation to minimize the disruption to the natural site. This may require some special engineering to make sure that the foundation is solid enough to last for centuries, but it is often quite possible. In your climate a well-insulated and well-designed passive solar home would be the best...but some very careful placement may be necessary to assure that the southern exposure to the sun is sufficient. Sometimes deciduous trees can obstruct the exposure if they allow enough light through in the winter time when you need it. As for plans that might work in your circumstance, many of those presented at www.dreamgreenhomes.com might be adaptable, although it might take some special redesign to accommodate this sort of foundation and floor.

Q: I am opening an art gallery on a very low budget and was wondering if I could get some input from you. The gallery is going to be based in Bangalore, India. More than a regular swanky, expensive art gallery it's a platform for emerging and budding artists to display their art, and we help them sell it. The area of the site is 50 feet wide by 70 feet long, east facing. We are looking at a basic temporary structure to house the paintings because they need protection form sunlight and rain. The rest of the area will be used for landscaping and to display art such as sculptures, pottery, home decor, apparel, jewelry, ect. ...anything that falls under the art genre. Kindly do suggest some contemporary yet inexpensive material we could use to design this place, especially where we house the paintings. Materials that help aesthetically and are also flexible for us to move around and for the paintings to be hung on it.

A: This sounds like an interesting and worthwhile project that you have in mind. Not knowing what local natural materials might be available there, it is a bit difficult to make recommendations. In a urban environment, there often many opportunities for recycling building materials that have been removed from previous construction, and this is an excellent way to source materials sustainably. If I were you I would start investigating this possibility through checking with companies that do deconstruction and might have a stockpile of available materials. Another possibility would be to locate a building that someone wants to have removed or partially remodeled and offer to do this for them. I once acquired enough fine used lumber from taking apart a large chicken coop to build a small house.

Q: I am a high school student living in southern Australia doing an assignment on "The Power of One". I have chosen to build a model of an eco-friendly house (approximately size of A3 paper). My preparation has consisted of researching: eco-friendly houses, their designs and floor plans, finding natural materials that could be used in the building process, how my house should be orientated (facing the north), energy efficient appliances and heating/cooling ect. such as solar, rain water tank, fluorescent lighting, cross-ventilation, insulation, compost bin. I am also planning on interviewing a local "green" architect on how he creates his designs and what he takes into consideration during the design process. Do you have any advice on what else to include in my "green" house model, or what I could make my model out of?

A: I suggest that you keep the design very simple because compact design is more ecological and easier to create. Research what natural materials are available locally, and consider using these for the construction...even possibly recycling materials.

I once made a kit of miniature earthbags by sewing material into little sacks, filling the sacks with sand, and then folding and stapling the ends to make them secure. These little earthbags can then be stacked into the shape of your house, either as domes or as vertical walls. It helps to make some little half bags to work with as well. This sounds like a fun project.

Q: What can be done with landscaping to be greener?

A: Minimize water use through landscaping with native plants, eliminating large expansive lawns, and capturing rainwater for irrigation.

Q: Can you tell us where most eco-homes are actually being built?  I mean, is there a certain place or state in which people go to build these kind of homes? 

A: Ecological homes are built all over America (see http://www.homes-across-america.org/index.cfm  for some examples). There are probably more of these types of homes built in the Southwest than other regions because there is plenty of sun there for passive solar designs, and because natural materials like adobe and strawbales have become historically more acceptable there.

Q: I was just wondering if you could please help me with 2 good locations that would be best for a sustainable house. For example a forest, desert, or some sort of climate habitat that did little destruction to the environment. If you could give me a reason why that would be great too.

A: The best place to build a sustainable house can be any place where there is enough water for domestic use, where you don't have to drive to where you need to go to work or shop, where you can use some of the local materials that are available for the building process, and where you have plenty of sunlight during the colder times of the year to heat the house with sunlight. It really doesn't matter whether this happens to be in a desert or a forested environment.

Q: I'm from the Philippines. I'm an architecture student. I'm proposing an ecological design in compliance for my thesis. My thesis is all about an eco-tech complex: hotel and events center. The challenge in this project is I'm designing and planning a combination of ecological design and high technology in a city. I just read some of the articles and I'm so glad that I learned a lot of things that will help me in my thesis. I hope you can give me some tips and encouragement in designing ecologically.

A: I am pleased that you are pursuing ecological design in an urban environment. While this can be more challenging than it might be in more rural places, most of the same principles outlined at this website still apply. Aspects of ecological design that employ high technology include photovoltaic systems for electricity generation or the use of "smart windows" that adjust themselves to conserve energy. Most of what I would consider ecological does not require such high tech solutions.

Q: My question is one of plausibility. For awhile now I've been thinking how great it would be to live in what I suppose one would call a "digital home" and was thinking about how I could work to make this happen. Now I know that this type of house would probably be about as un-"green" as one could be. I've read some site talking about how a digital home could help keep things "greener" by monitoring wasted energy uses and correcting them and I think there is a point in there somewhere.

Anyway my question is do you think it is possible to merge a digital style home with a green style home? If nothing else I do hope that when I make my home a reality (in the next 5-6 years hopefully) that it can be the most environmentally responsible way possible (in my mind it has passive solar and maybe geothermal etc). To pose the question a little differently do you see anyway we can merge the digital world (and home) with environmental responsibility, and have the best of both?

A: The simple answer to your question is YES, it is possible to combine high tech digital technology with low-tech concepts for living ecologically. I am enamored with both approaches myself, and rely on computers for both design and communication, while preferring simple passive designs over more complex active solutions to heating, cooling, etc.

I have a friend in California who has been working on his dream home for many years and showed me his sophisticated centralized computerized monitoring system for lights, audio, ventilation, communication and several other functions. He even became factory trained by the manufacturer of the system in order to be able to install and program it. This degree of precise control doesn't appeal to me that much, but for him (and perhaps for you) it is highly desirable. I can see how, under some circumstances, this approach can conserve energy and make life simpler rather than more complex...

Q: I am working on a small dome at the moment but plan a larger project and I want to incorporate a large vaulted room as well. How would be the best way of going about this construction? Do I need to build a form?

A: In my experience vaults are better accomplished with relatively small masonry blocks that are made of stabilized materials, such as fired bricks, stabilized adobe blocks, AAC blocks, cement blocks, etc....so that you don't have to worry about the material deforming if it ever gets wet. You need to make sure that the walls that support the vault are sufficiently buttressed to withstand any lateral pressure applied by the vault (this can be done with very thick walls). And yes, working with forms is pretty much essential for success.

Q: I'm interested to know whether a sustainable building can look beautiful and whether you can design and build iconic buildings that will not only last longer but will be referred to as classic examples, like say the opera house in Sydney- Australia.

A: This is an excellent question. You are describing a book that perhaps still needs to be written. It certainly is possible to design and build beautiful, sustainable buildings, and this is a worthy goal.

Q: Do you own a sustainable home? If yes, what sacrifices did you have to make to successfully maintain this sustainable lifestyle?

A: I built and lived in an extremely sustainable home in the mountains of Colorado, with very little sacrifice involved; in fact a sustainable home is often a more comfortable and convenient home than the conventional ones.

Q: I'm building a new house. I've been looking at windows. In my region the most energy efficient windows that I can find are vinyl. There are some wood windows that are similar in terms of U values but have a much lower SHGC and therefore will not contribute much in terms of solar heat gain. So the overall Energy Rating (ER) for the wood windows is lower. The ER rating for the vinyl windows is about 36 and for the wood windows is 22. The wood windows are made from Douglas Fir, and they are supposed to be available in FSC certified wood. (By the way, I live in Kingston, ON in a climate that is fairly cold. We are planning a sun-tempered design with ICF walls and geothermal heat). My dilemma is the environmental toxicity from the whole lifecycle of vinyl and whether this outweighs the energy savings that we will achieve. How do I balance the overall environmental benefits and harms. I should also add that I prefer the look of the wood windows but they happen to cost twice as much.

A: It sounds like you have done a lot of research about this and have a pretty good idea about the trade-offs of your various options. I have installed quite a few vinyl windows, and they do seem to perform well, although I also prefer the wood aesthetically. It is almost impossible to sort out which is "greener," when you are comparing toxicity vs efficiency; this becomes a matter of personal preference. I'm afraid that I can't help you much with this choice...

Q: I happened to notice that there is very little 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.

A: You 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 would equally apply in an urban setting. In districts where housing goes above 2 or 3 stories, it is difficult to use some the more natural techniques, but the principles still apply. Also much of the movement towards "sharing facilities," such as cohousing, can be done in cities.

Q: 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 a a large parcel of land.

A: 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.

Q: I saw a program about building cheap, sustainable housing years ago and the house was just curves - there wasn't even doors, just curves separating spaces - and I have had a thing about building a curved house every since.  I am investigating rammed earth cause I am looking into buying land in Colombia (I've been in Latin America for a year now) and rammed earth would be good for the hot climate...just trying to work out how curved I could make it with rammed earth.  Apparently CAT are currently building a cylindrical conference room/space with rammed earth.

A: I suppose that it is possible to ram earth into a curved form, but this is very unusual; every rammed earth project that I have seen is rectilinear, with vertical walls. Earthbags, or cob, would be much easier to form into curved shapes. Any of these are about the same in thermal properties, if the bags are filled with soil, which is to say that they are only comfortable in a fairly moderate climate. If there is much sustained heat, you are much better off with an insulated shell, which is why I filled my earthbags with crushed volcanic stone, but you can also use discarded rice hulls.

Q: There seem to be differing opinions about earth buildings in wet conditions, some say there is no problem, but others say that earth buildings can deteriorate.

Like any building technology, earthen buildings require appropriate foundations and roofs. If these details are taken into consideration, then earthen buildings can, and do, last for centuries.

I guess it depends on the finish, and wonder what finish is water proof and eco-friendly.

Actually, it is best not to apply a waterproof coating on an earthen structure...it needs to breathe to remain healthy. Waterproofing can trap moisture inside the walls, which can lead to severe deterioration, or even collapse. Earthen plasters that are stabilized with some Portland cement, emulsified asphalt, or lime plaster are quite durable and can breathe.

Q: I have been contracted with Midwest Minnesota Community Development Corporation (MMCDC) to investigate different types of home construction. MMCDC seeks to improve quality of life for Native Americans on the White Earth Reservation in north central Minnesota through improved housing and generation of income. I need to evaluate different types of housing appropriate for our climate (light clay, cordwood, straw bale, rammed earth, etc.) that can be constructed with locally available labor and materials. Are you aware of any recent comparative studies that have been done on these different types of super insulated building techniques?

I am not aware of any comparative studies done on different types of super insulated building techniques, although there may be some out there. A simple analysis could be done regarding the average R-value ratings of the various wall systems, and this might be valuable for assessing this. While strawbales were initially valued at around R-60, they have since been devalued to about half that. Cordwood varies with the species, width of wall, etc., but the average might be about R-20. Light-clay again depends on the wall thickness and compaction, but it will be less than a strawbale wall in any event. Rammed earth requires the addition of some rigid insulation on the exterior to provide worthwhile insulation, so this depends on what choice is made here.

Here is a list of goals and objectives that we are looking to meet: A. Culturally appropriate housing that can be constructed with the locally available labor and materials.

Probably the most technically challenging method of those mentioned above would be rammed earth, because it requires the use of heavy equipment and well-engineered forms. The other methods, if the materials can be found locally, would be easier to learn and achieve with manual labor. I cannot assess how culturally appropriate any of these would be...I do know that strawbale buildings have been built successfully in the Dakota reservations.

B. A construction technique that maximizes income generation while maintaining maximum affordability

There is a lot of manual labor that goes into any of these forms of building. Again, I would think that strawbale, cordwood and light-straw-clay would be better in this equation than rammed earth.

C. Housing that is energy efficient (super insulated), durable and will be in compliance with state and local building codes.

All of these have this potential, if the design and materials choices are carefully considered.

Being in the construction and remolding business I approach this from a pragmatic point of view when it comes to documented, tested, research-based, "alternative" construction. I really like the idea of home grown techniques, be it cordwood, straw bale,etc, BUT the devil, as the saying goes, is in the details How can I learn more about your research on "alternative construction materials and methods"?

Well, I suggest that you keep up the inquiry, study what is available from my site and others, check out some of the books, and possibly experience a workshop or two on methods that you are considering.

Do you know of any current studies that compare the different construction techniques: light straw-clay and cordwood are two we are considering taking a closer look at.

Again, I am not aware of any such studies. My personal favorite in your situation would be cordwood, if the wood is available locally. This is because even the gathering of the wood can become part of the income stream for the workers; the basic technique is fairly easy to learn; with softwood species the R-value can nearly equal strawbale; once the wall is laid, there is no further finish work needed, such as plaster, etc.; with post-and-beam designs, cordwood will meet most all code requirements; and the interior mortar will provide a nice amount of interior thermal mass to help keep the home comfortable.

Q: How do you conserve water with your designs?

A: Some designs actually capture rainwater for reuse...otherwise water conservation is mostly a matter of choosing more efficient fixtures and appliances to be installed, and designing landscapes that require little water. More radical options include the possible use of compost toilets or gray water reuse.

Q: In what ways do you use utilities (plumbing, gas, electricity, etc.) that makes your buildings efficient?

A: The objective is to use as little of these utilities as possible, so if a home is designed to generate its own electricity from solar panels, heats its water with solar panels, uses passive solar concepts for space heating, and uses efficient appliances, then this will go a long way toward realizing this objective.

Q: We are trying to determine the best way to build 17,000 - 300 sq.ft. houses for the people in Nicaragua. We have a budget for $2,800/unit. We have unlimited timber and cheap labor. We would probably want to go the prefabricated route. Maybe OSB, ISP panels? May use wood or steel frames. What is the best product available in your opinion? We do not want to use cement though. I know you are familiar with the weather in Nicaragua so the rainfall and high winds would need to be taken into consideration.

A: You want to build 17,000 homes??!! This is certainly ambitious!

I am always interested in the most energy-efficient and sustainable approach to building, because this is becoming increasingly important. This means working with local, natural materials when possible. I don't imagine that OSB nor SIPs are made locally, so this would mean a lot of transportation and manufacturing cost (money and energy). Plus, these materials usually require a concrete foundation.

If timber and labor are unlimited, then I would suggest using these resources, along with perhaps the local soil for this project. I have been a long-time advocate of earthbag building for some of these same reasons, and have put together a website about this technique: www.earthbagbuilding.com . Earthbags can create their own foundation (no cement needed).

I suggest that you consider exploring this method for making the walls, and then use the local timber for the roofs. Since the roof needs to be well-insulated, lightweight earthbags filled with local straw, rice hulls or volcanic stone can be used (see http://earthbagbuilding.com/articles/ceilings.htm  ). Probably the most durable common roofing material would be locally available "tin" roofing, but ceramic tiles are also possible.

This way you can stick with the local vernacular building shapes that the people will feel more comfortable inhabiting.

Q: I had some spare time on the computer and Google earthquake news. All of the news show lots of statistics on damages caused by earthquakes. Most of them imply that the buildings that collapsed were old, cheap, and were not following state approved building codes. Yet none of them give statistics on how many steel and concrete buildings collapsed.

In El Salvador where I am from, I know for a fact because I was there, that most of the people that died in 1986 were in concrete and steel buildings. In Colombia, in a 1990's earthquake, I read in a book that most of the buildings that survived were cheap bamboo structures, and the conventional and modern ones failed. I would be curious in the detailed numbers for steel and concrete, wood, old earth, etc.
Also on how many deaths in each type of building construction. I would imagine that rurally there are lots of small buildings but not that many deaths per building. In the major cities, I would imagine that one building with many floors would be responsible for many deaths.

A: I think that you are right that the danger of earthquakes is much greater in cities, where human density is much higher and the buildings are generally much taller. They say that the safest buildings are those that can flex some, like the simple bamboo structures. Earthbag domes are also resistant, partly because they do not need a rigid concrete foundation and can roll with the punches better. Also, the shape is amazingly strong.

Q: I have over 30 years experience in flat roofing of many types. I am going to build in a few years and I would like to know what advantages there would be with a flat roof as opposed to a gable roof for a residential building (example: heating and air conditioning on roof or cost of gable trusses to be replaced by rubber products or waterproofing and sod)

A: There are certainly advantages to both flat and gabled roofs. I live in Mexico where virtually all roofs are flat, and one of the main reason people do this here is that it makes it very easy to build another story onto the existing building; in fact they often leave extensions of rebar intact, so that walls can be tied in this way. Also, as you suggest, flat roofs are much easier to convert to earth-sheltered roofs, and there are many advantages of this. In favor of sloped roof systems, they are often better for rain water catchment, and solar panel applications, they are less prone to leakage problems, they are easier to insulate, and they provide some interior space for storage, ventilation equipment, etc. So, it really depends on your plans for the building, which is more suitable.

Q: I am a Saudi citizen studying sustainability in Australia and I am intending to make a change when I go back home after I am done with my studies. I am interested in building a strawbale house when I go back to Saudi Arabia. How good does an idea like this sound to you, knowing the climate we have in Saudi Arabia?

A: It is good to hear that you are interested in furthering sustainable architecture in your home country. Clearly a new attitude toward building, as well as living in general, needs to occur there. Unfortunately Saudis have embraced much of the Western ways of planning and building urban environments, and this will not serve them in the end.

As for using straw for building there, I think that if it is available it would be a good idea to use it. Straw is a good insulator and will guard against the entry of heat into the house, while not holding accumulated heat. My concern about using straw is that, like most everything else in your country, it must be imported, which lessens its sustainable quotient. It is always better to use local, indigenous resources.

I noticed that there is quite a bit of volcanic stone in the region, so a light-weight volcanic stone could be used, perhaps crushed and placed in earthbags, as I did in building my house in the U.S. (see http://earthbagbuilding.com/projects/hart.htm ). You can see many other examples of earthbag building at this website. Other local resources are perhaps dead coral (this was used extensively in old Jeddah), and of course clay/sand soils for adobe, rammed earth and cob construction. If the walls are thick enough, they will buffer against the outside heat. Each of these techniques are shown at this website.

Another option might be to go underground to avoid the heat. If I were to build in your country, this is what I would do. Earthbags can be used for underground walls. Once you are able to build such a sustainable home, then it can become a demsonstration model for others to follow.

Q: I am interested in building a multi-level round or hexagon tower (after having visited a grain solo that had been converted to a condo). I originally thought about papercrete, but I live in New England and not sure how it would fair here. I am also considering straw bale and now also cargo containers after reading your article. If I were to build with papercrete, I would prefer to purchase already made jumbo bricks and do the building and stucco work myself... Any suggestions/thoughts?

A: Both strawbales and papercrete blocks have a distinct advantage of being insulating materials, which are critical for comfort in New England. They also both require breathable plasters and need to be kept out of the weather as much as possible, and this last factor is somewhat difficult with a high tower. Maybe if it were designed with a series of tiered roof rings located at each level, most of the rain could be kept off the walls. Strawbales do not lend themselves to circular walls very well, but they can be curved a bit if the diameter is large enough. Certainly a cylinder is a very strong shape that is virtually self-supporting. I don't know of anyone manufacturing papercrete blocks yet, although there is one company starting up in Texas. The walls could also be built with earthbags filled with an insulating material such as crushed volcanic stone or perlite. As for using cargo containers, I can't imagine how to assemble them into anything resembling a round or hexagon tower.

Q: What alternative energy sources have you discovered work? Do you build from local/natural resources? Is there a community you live in or are you self-sufficient? When did you start building? Are you gardening? Who do you recommend as a source in the US?

A: I have been involved in alternative building for decades, having grown up with a father who loved to build with stones and recycled materials. I worked for a long time as a carpenter/remodeler, and eventually built my own house in Colorado with earthabgs, papercrete and recycled materials. You can see more about this here.

This house was designed as a demonstration for sustainable architecture and I feel that it accomplished this goal. At over 8,000 ft. in the Colorado mountains, the passive solar design performed admirably, sometimes providing enough heat in the dead of winter to go through a night without any other supplemental heat. The house was equipped with both solar water and solar electric panels, and these also performed quite well. We even had a solar heated hot tub!

This house was built almost entirely from natural, local resources. The recycled (misprinted) earthbags were filled with either the local soil from the site or with a crushed volcanic stone (scoria) that was harvested nearby. The papercrete was made from waste paper gathered at the dump or post office. The floors were made from local flagstone and adobe. Much of the supporting framework was created from wood gleaned from our property or nearby forests as standing dead trees.

This house was part of the greater Crestone, CO community, and while it was approaching self-sufficiency, it was not entirely so. We have since sold the house and moved to Mexico, where we are part of another sort of community of mixed cultural experience.

We commenced building the Crestone house around 1997 and finished it in 2000, just in time for Y2K. In fact we enlarged our naturally cooled pantry in order to be able to store more food in case of any emergency. We did have a small attached greenhouse as part of the design, and it provided some supplemental produce, although not nearly enough to live on. During the very short (3 month) growing season we also had an outdoor vegetable garden. Gardening in Mexico where we are now (near Lake Chapala and Guadalajara) is much easier, as the season is year round!

I'm not sure what you mean as a source to be recommended. I feel that one of the best resources for becoming educated about sustainable architecture and natural building is this website. I have several other related sites as well: www.earthbagbuilding.com , www.dreamgreenhomes.com and www.sunvee.com .

Q: Out of the building types you have on your site... which is the quickest to build with 2 people, and which one would be the easiest to move?

A: Probably the quickest to build and move would be a yurt, such as are described here. Beyond that, most building systems are not easily portable...

Q: Is it possible to build a small house on a brick-on-sand foundation?

A: While this is possible, it may not be your best choice. Bricks needs a completely stable foundation to keep them from forming cracks over time, and sand is a somewhat shifty material; wind and water erosion can affect it. You might get by with creating a rubble trench foundation with gravel and or stone that is then capped with a layer of concrete that will accept the brickwork. In Mexico, where most building it done with bricks, the foundation is usually made with mortared stones that go below any frost level and at least a foot above the grade.

Q: I am purchasing a lot on an island off the coast of Belize. It is a small, mostly wet coral atoll. When I visited the island 5 years ago they were building a home on a partially wet lot and the builder told me that construction in the wet areas was not a problem because all the homes have to be built at least 6 feet above sea level and support piers would be placed in holes drilled in the coral substructure of the island. When I returned to the island this month I discovered that the home that is now finished has had to be repaired in the wet areas because the pilings had sunk considerably. Was this just poor construction or is the idea of sinking piers for foundation support in coral fatally flawed?

A: Hmmm...sinking piers doesn't give one much confidence that the practice is sound. It might have been a matter of poor construction, but perhaps there is a more fundamental underlying problem. I suggest that you question other professionals in the area about this to find out more. If this has been a successful practice for decades, then you might have more confidence. It really depends on the specific geology, so you need professional opinions from someone in the area. In any case, I would caution you to not only check this out thoroughly before starting any building project there, but also consider putting your building on very high piers indeed, given the projections for sea level rise from global warming.

Q: How many stories high can a green/alternative building be constructed? Or, how many stories high, or how many square feet, have buildings of this type been built? Can such a building be constructed as a civic or institutional building (eg. city hall, university, hospital, museum &/or corporate center, etc.)?

A: It is impossible to generalize about alternative construction in this way because there are so many variables and methods of building, and so many designs that might, or might not work. Suffice it to say that almost anything is possible with proper engineering and research having been done.

C: I asked this question because I've seen many examples of these constructions from the present back to the early 70's up & down the west coast when there was both an aesthetic interest in alternative/counter-culture constructions as well as alternatives in light of a growing awareness of limited resources triggered in particular by the oil crisis of the period. The difficulty I've felt about these alternatives (which I both aesthetically love & environmentally admire) is that they seem to flourish predominantly in beautiful natural, sparsely settled environments while also addressing the needs of individuals, families and/or small isolated communities. This again is why I asked you this question as your experience in this realm is obviously far greater than mine. My feeling is that until this type of construction addresses, or can address, society's (mass society's) larger communal needs -schools, universities, museums, hospitals, city halls, corporate buildings, office buildings, apartments, etc. etc. - it will be a type of construction that will remain very appealing & idealistic but nonetheless very much at the margins.

I say this while especially admiring (among its many aspects) the work of Michael Reynolds, particularly respecting his efforts in Indonesia, New Orleans and now in Haiti...but, despite their urgent necessity, they are still limited to addressing intimate, more personal concerns rather than larger social, urban and / or industrial, issues, concerns and needs.

Q: In the latest bush fires, metal roofs were also destroyed in temperatures estimated to be in excess of 1000 to 1300 degrees, so what else is there? We really need to find a roof system that works, not only for bush fire proofing, but also for rainwater collection and extending out into eaves or verandahs.

A: Good Lord! I've never heard of metal roofs failing in fires, but I suppose that the rafters and framework that support it might. If this is true, other roof systems, such as clay tiles, might also fail. The only other system that comes to mind is solid masonry, such as reinforced concrete. This would require walls and supports capable of bearing the weight. In Mexico roofs are often built up with steel I-beams spaced about 1 meter apart, and then the space between them is filled with a series of small arches of standard bricks. Over this is laid concrete and special roofing paint. These roofs do not burn.

Yes it was very serious, all roofs normally used were found to be insufficient to withstand that ferocity of heat and fire. Solid masonry atop strong earth walls seems worth considering, but I am also very interested in the Mexican roofs you spoke of. Can you direct me to further information about them, written or explanatory hopefully, plus images? I'm also interested in these roofs as it seems to me that some of the required items may be found as recycled materials. And do you know what the special roofing paint is?

It is really very simple. After the beams are pinned into place on the top of the wall, a single metal form with the exact curve of the arch that will support one row of bricks is used to temporarily mortar into place the bricks. Once this row is in place, you can just slide the form to the next adjacent spot and continue the brickwork. It actually proceeds very quickly, and uses no further metal reinforcing. And yes, you could use recycled bricks and I-beams if you had them. The bricks can be placed either flat or on edge, as the photo shows. Over this is poured concrete to make a smooth roof surface. In one case I saw an intermediate layer of tar paper embedded in the concrete. The roof can be inclined for better drainage, or done level to use as the floor for a second story. This system is so strong you could park your car up there!

The most common roof paint is made specifically for this purpose and is a latex product very similar to elastomeric paint. They called "Impermeable" paint.
Incidentally, the photo shows another building in the background with a variety of domed and vaulted roofs, and all of these were created entirely with brickwork. Mexico has many talented masons.

Q: I was thinking of building without a basement to save money, but do want year around food storage in a root cellar.

A: While basements do cost money, they provide so much benefit that it may be worth it. You generally have to build a foundation for the house in any case, so going a little deeper will give you the cold storage for food, as well as double the living space and thermal benefits. It is possible to build a basement with earthbags, which might be much less costly than the conventional poured concrete...if the local authorities will allow it.

Q: I am a freshman at Columbia University and have been very intrigued by green home building (especially Earthships) ever since seeing Garbage Warrior. I would really like to learn more about the schematics of such homes that already exist, but am also curious as to whether or not there are any urban designs you could show me. Most of the Earthships I see are in remote areas, (due to construction regulations) but I'd be really interested to see plans for people who love city life but want to live independent of the city's power grid.

A: Urban life can be one of the most sustainable ways to go. It is true that most "green" home designs focus on more rural situations, for numerous reasons, including regulation. But there is no reason why urban architecture can't also be green Actually there are quite a few designs that are rather compact (under 1000 sq. ft.) that would fit on most city lots.You can find these at www.dreamgreenhomes.com. Many of these plans could utilize solar electric panels and be off-grid if you want...or you can retain the grid connection and do a net metering situation where the power company buys back your power and supplies backup power when necessary. This means that you don't necessarily need to maintain batteries.

Q: Do you have any advice for those who are looking to launch a career in your field?

A: My advice for anyone wanting to find their right work, is to "follow their bliss" and if this leads you in the direction that it has for me...great! The most important thing is to become self-realized and experience your true potential. You'll know what is right because it will feel right.

Q: I live on a farm in rural Nebraska and I am looking into the various types of sustainable building methods and materials for a new house. What would be the best method/material for building in Nebraska when my main focus is cost savings - now (low construction cost) and in the future (energy savings) (in that order)? I have basic carpenter skills and hope to improve upon my framing/construction skills prior to tackling this project. I would love to find something with low cost of materials and something simple enough that I could build it myself. I'm really curious about whether it makes sense to combine a berm home design with other methods and materials, such as rammed earth or shipping containers.

A: Well Nebraska is the original home of strawbale building, which can be fairly simple to do (especially the walls), and involves a lot of basic carpentry skills. Yes, it does make sense to create a bermed house in that location, and there are various materials that you might consider using in that area. Often a hybrid building design is the best solution. For bermed areas, I would suggest earthbags, stone, ICFs...anything that can't potentially rot if it gets wet (strawbale would not be good here).

Q: Any suggestions on low tech / low cost suspended slab floors? Typical formwork seems too expensive for the type of jobs I'm envisioning. I'm trying to come up with a simple way to sheet the top of floor joists. Foam is too weak. Plywood would rot. Don't want to use pressured treated ply. 1/2" cement board is pricey and could snap.

Ferrocement is one possibility. Stretch wire mesh over the floor joists and apply two coats of cement -- 1. first coat between the joists (with one above above, one below who press against each other), 2. second coat covers the whole floor about 1/2" thick, 3. lay tar paper and pour the slab. Another way is to run smaller perpendicular joists to create a grid and set concrete board on top. Any other ideas?

A: Concrete decks are very common in Mexico, but they are usually at least 3 - 4" thick and use a rebar grid for reinforcement...obviously not cheap. But they do span amazing distances this way without any joists at all. Another common approach in Mexico (again, not cheap) is to place steel I-beams at about 1 meter apart and then bridge between them with slightly arched bricks laid over a moveable form. The lower ceiling can be left exposed and the upper deck can be smoothed over with a concrete slurry. This makes a very strong floor that could even be used to park cars on.

I'm not sure that I would trust your 2-ply ferrocement to be stiff enough for the jumping or banging that can occur on a floor...makes me a bit nervous. Probably some kind of built-up ply like your last suggestion would be more practical.
Or how about experimenting with corrugated roofing as a base over joists, and then pouring a light-weight concrete over it to level the floor and stiffen it?

Q: Is fossil fuel being used to build these home? If there is, how much less or more compared to how much is use to build regular homes?

A: It would be very difficult to build a house these days without some use of fossil fuel, but many of the techniques shown at this website can certainly minimize the use of fossil fuel. For instance, I recently built a small underground earthbag dome that used the native earth to fill the bags for the dome. The polypropylene bags themselves and the sheet of plastic waterproofing undoubtedly consumed some fossil fuel in their manufacture, but that is all that was consumed in the entire project. There are too many variables to give you percentage of fuel savings, however.

Q: I'm looking for either software that can bring my design to reality or advice as to my next steps to take my concept drawings to plans to material lists to structural analysis. I understand that I can hire a firm to complete the aforementioned but I wish to be more involved and then submit for structural analysis.

A: I have used Google's SketchUp as a design program for architectural work. It is free and very powerful. You can actually model solar penetrations for passive solar designs with it. Professional architects and engineers generally use AutoCAD programs and files, so this format can be sent to them directly, but these programs are quite expensive.

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I specifically disclaim any warranty, either expressed or implied, concerning the information on these pages. Neither I nor any of the advisor/consultants associated with this site will have liability for loss, damage, or injury, resulting from the use of any information found on this, or any other page at this site. Kelly Hart, Hartworks LLC.