Climate Issues Related to 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: I will be building a house in the next few years on my own property in the country (at last!) and I am very much in the mode of building a home which is natural and safe for us to live in. I have been reading a lot about straw bale and have just about dismissed it as a method of building except in dry climates. We are so humid here and I have heard of no strawbale building here except one house in Alabama. Is there any information about building environmentally in the retarded South. (SC).

A: Almost all natural building techniques, including strawbale, will work fine in humid climates if certain basic precautions are taken. Walls need to be protected by wide eaves, foundations need to be high and dry, and the walls should be breathable so they don't gain moisture and hold it.

Q: I am in the process of designing and building a home on a tropical island (Saipan, 15.5N, 145.5E, US Commonwealth of the Northern Mariana Islands, near Guam). I would like to use sustainable architecture and building principles, and have done a fair amount of studying architectural principles for hot humid climates coping with earthquakes, typhoons, and 90" rain each year. I have so far come up with a courtyard plan, "U" style house built off the ground. My question is this: how can I build using sustainable architectural principles, when all of the building materials are brought in, and cement is the only economical medium? Thanks, great internet site, very helpful!

A: I have a couple of questions about your situation on Saipan. 1) What are the temperature variations over a year? Do you basically just need protection from the weather, or do you also need to significantly moderate your temperature? 2) You say that all building materials must be brought in. What sort of soil do you have? Sand, clay, crushed shells, silt? What sort of vegetation is available? Shrubs, trees, grasses, reeds, bamboo, etc.?

R: The temperature variation here is quite small throughout the year, usually from 80 to 90 in the daytime, and 75 to 80 at night. What varies is the humidity, in the monsoon it is very high. The prevailing winds are east-northeast, about 45% of the time. We have time periods when we have the doldrums, usually twice a year, March/April before the rains, and October before the winds turn around and come from the west. I'd like to build using those figures to capture as much wind as I can to flow through the house. As for local materials, they do mine the coral aggregate for roads and other projects, but no one locally makes lime out of the coral. We have a lot of sand, but it is not used for construction due to erosion concerns. There is bamboo grown here and there, mostly as an accidental plant left in the yard that grew out of control, but nothing for commercial purposes, and no companies import it that I have been able to find There are a lot of ironwood trees here (aerially seeded after WWII, as the US bombed Saipan down to bare rock), but I can find no one who processes them or grows them for the local construction market. Clay is not a medium I have heard of being used, although we have it here. Most imported wood has to be heavily treated to last more than a few years. Saipan's bugs and termites are very healthy and hungry. As for growing vegetation, everything grows very fast. In 4 months, my banana trees went from invisible to 6 feet tall. Basically, Saipan is in the 1950's in terms of conservation, renewable building, and climate responsive building design. Most of the construction companies are run by Filipino's, and the Philippine construction business is not noted for its conservation efforts or its knowledge of "green building." They build everything with the cheapest cost and quickest build time in the forefront of all planning. So, any help you could give would be greatly appreciated. Thanks very much.

A: It doesn't sound like the folks who run the infrastructure there are very enlightened. I've put a little thought to your question, and come up with this suggestion; it would potentially give you shelter that could survive virtually any wind, rain or insects and would be on the cooler side, with breezes when available. Also it would be very inexpensive to create. What I suggest is something similar to what I have done, using earthbags filled with the soil from your site to create a dome or domes, which would then be plastered with a cement stucco. A vapor barrier could be placed over the domes before they are plastered. Some portions of the dome could be bermed with more soil to help moderate the temperatures. Wind catching towers can be employed, similar to what is used in the Middle East, to direct the wind into the house. The earthbag page at www.greenhomebuilding.com has a lot of information about this type of construction, including books and videotapes.

R:Thanks for the info about the building style. Unfortunately, I won't be able to get a building permit for that type of structure. The building permit people, AKA the neanderthals, don't believe that earth-filled earthbags will be sufficient. They believe that not even if the earth was highly sterilized, like potting soil, would it be any good, because the humidity would cause mold and growth, and the rains would eventually enter the structure and cause problems. I wouldn't have the faintest idea how to sterilize that much earth, and it wouldn't matter anyway. They are also concerned with the loss of topsoil used in the earthbags, and despite my suggestions to check out your website, my requests fell on deaf and dumb ears. Back to the drawing board. Cheers!

A: I'm sorry to hear that they are being so obstinate about this. You wouldn't necessarily have to use top soil. It could be other sandy soil or gravel or crushed shells... Also the soil could be mixed with portland cement, so that it would become what they call soil cement, which would eliminate any problem with moisture causing mold or growth or other such problems. Don't give up; I think this type of building could solve a lot of problems around the world. It has been permitted by code officials in the United States, and tested for earthquake soundness, etc.

Q: My husband and I live in Omaha, Nebraska. What sustainable home building type is most appropriate for our climate. (extreme cold to very hot and humid)?

A: In this kind of climate you want to have a well-insulated house to protect you from those extremes. Nebraska is the historical home of straw bale building, so this approach has been tested by time http://www.greenhomebuilding.com/strawbale.htm. Other approaches you might want to investigate would be earthbags (such as my house), underground or earth-sheltered building , or AAC.

Q: I would love to hear more of your building ideas as down here on the coast of Texas we have to build up off the ground and in wood. Main problems are Wind and excessive sun, termites that grow fatter by the day as they munch through endless planks of wood. Most buildings here rely on A/C and homes are far from being energy efficient.

A: The best way I know to combat the problems that you mention is to build into the ground with earth. This gets you out of the wind and sun, keeps you cool, does not appeal to termites and can eliminate the need for air conditioning. Earthbags are a good way to go.

Q: I live in Puerto Rico. I'm studying Environmental Engineering and my dream is to be able to live in an environmentally harmonious home. I was wondering if the houses built from the materials of sustainable architecture are hurricane proof, since Puerto Rico is an area of very high predisposition to this type of natural manifestation. If the materials are not hurricane proof, I would then like to know what other options I have. Thank you for your time and attention, and most of all, your love for nature!

A: It is hard to generalize about how natural buildings hold up to hurricanes, because there are so many variations in materials, designs, and techniques of building. I would say that it is certainly possible to build naturally and sustainably in such a way as to withstand the force of nature...in fact I consider that to be one of the main tenets of sustainable architecture: that buildings should be built to last!

For instance, the house that I built for myself is composed of earthbags shaped into domes and I dare say that it would hold up to hurricane winds with little damage (maybe some broken glass?) Most other methods of natural building, including cob, adobe, rammed earth, strawbale, and cordwood should withstand storms, if proper attention to engineered details is adhered to. The most vulnerable element to designs built with these materials would be the roofs, which would have to be fastened to the walls extremely well. That is one reason I would recommend domes or earth-sheltered designs in your area.

Q: I just bought land in the rainforest of Big Island, Hawaii. I wonder if you could recommend materials that would suit building in a humid, warm environment, and what plan features you might recommend to have shelter while at the same time creating a feeling of being open to the beauty of nature all around me. Is there a site you recommend I visit, or plans for tropical environments?

A: The typical approach to building in a warm and humid environment is to build off the ground and provide lots of ventilation. Since the climate is rather moderate, there is not a great need for insulation...mainly a roof, simple walls, and a floor. I have wondered about going in the other direction: digging into the ground to combat the heat. You would still need to provide good ventilation to control humidity, and carefully arrange window openings to keep your views, but this can be done.

Q: What kind of materials would you use for building a house in earthquake land?

A: There are many materials and designs suitable for earthquake country; partly it depends on what materials are available to you. Wood-framed houses can often withstand considerable shaking if they are well-built, but wood is not so easy to come by any more and using it tends to deplete the forests. A material more readily available is the soil beneath your feet, which can be put in earthbags and used to build domes that can withstand earthquakes. You might look at some of the pictures and read the information available at greenhomebuilding.com/earthbag to get some idea of how to proceed.

Q: We are a young couple who live in the Caribbean island of Puerto Rico. We would like to experiment with some kind of eco-building here in this 'Tropical rain forest'. What kind of eco-building techniques do you suggest that we look into?

A: In many ways tropical regions provide much more latitude in choice for design and materials concepts. It often isn't so necessary to focus on insulated structures as the only appropriate mode, so that creates more options. You could really utilize any of the materials listed at this site and create a comfortable home. I would suggest that you carefully look at using local materials, since that is the most sustainable, and usually the least expensive. I am not too familiar with what is available in Puerto Rico, but I would suspect that bamboo, stone, cordwood, and earthbags might be good choices. As for design, I would study the local vernacular architecture so see what has worked well historically; often, light-weight, airy designs are utilized. It would depend on the water table and susceptibility to flooding whether underground or earth-sheltered designs would work. If keeping cool enough is the main concern, this strategy may be a good one.

Q: I want to build a small, healthy home in Newfoundland, Canada. What kind of natural shelters would be an option here, cold winters -10 C average, snow, lots of wind, rain, humidity? I am single mom and need to build inexpensively.

A: You have many options that would likely suit your needs. You definitely want a well-insulated house in that climate, and a design that provides at least some passive solar heating when the sun shines. I would recommend investigating strawbale, cordwood, or earthbags as possible techniques to explore. The cost of building depends on many factors, but can be done fairly cheaply, especially if you do some of the work yourself and shop carefully.

Q: How do green house construction methods vary across the country when considering things like climate?

A: Being sensitive to the local climate is very important with green building, and this is primarily a matter of good design, such as utilizing passive solar designs  that function well for the specific location.

Q: I am having difficulty understanding what homes are best for hurricanes, fires and tornados.  I live in Florida and am really having difficulty finding out this info. Any ideas?

A: I would say that the very best homes for the kind of hazards that you mention would be underground, earthbermed, or earthsheltered homes, since they essentially place the bulk of the home out of harm's way.... see Keep Your Cool. Other forms that do well in these situations are domes constructed of concrete, like the Monolithic domes or perhaps earthbags homes, like what I built.

Q: What inexpensive, sustainable, safe home design would you suggest for disaster victims, such as, the tsunami people, New Orleans people, etc? Could the home be constructed quickly and expanded to more rooms? It seems that past suggestions from other home designers have involved more money than victims can afford or complexity of design that takes too much time and resources. The idea is to provide many, safe, small, inexpensive homes in as little time as possible, in a wide spread disaster. I am familiar with the Safe-R home design that has merit.

A: One emergency earthbag design that is inexpensive and fairly quick to build is outlined at emergency shelter. It may not be that easy to expand...

Another way to go is with SIP's, such as the small design at http://dreamgreenhomes.com/plans/2manhut.htm . This concept would be easier to expand upon.

C: I worked with the Red Cross in counseling victims of the tornado destruction in Eagle Pass, TX a couple months ago. A couple of effective techniques to help the victims was removal of destroyed housing materials to get to the foundations. Secondly, community centers were turned into victim centers for food and sleeping cots. The Red Cross and Salvation Army were great. FEMA was again not so helpful and missing from work areas when I was there. Many of the victims had little to no resources for re-building, but neighbors worked for free and donated materials. For some reason, I am very compelled to find better ways to provide housing to help the victims.

Q: We are helping to rebuild the gulf coast of Mississippi and I would love to speak with you about your opinion.

A: In general my opinion is that it is foolish to rebuild in places that are inherently vulnerable to flooding (such as most of New Orleans); why temp fate, especially with the prediction for increasing sea levels and ferocity of storms? Rebuild on higher ground in areas that are not subject to inundation. Then, I suggest that you follow the guidelines listed at this website,  where 13 principles of sustainable building are outlined. There is a lot of leeway in doing this, depending on local resources, life styles, finances, codes, etc.

Q: I'm an architecture student from the Philippines. Since our country encounters several problems on flooding yearly, what planning measures (for example, in houses) shall we take to reduce property damage? Is there any solution to this in a sustainable way, aside from elevating the structure to a certain height? What innovative, yet eco-friendly materials shall we use to attain a flood-free house or structure?

A: First of all I would advise that you consider using only building materials that are not adversely affected by moisture, so that even if the home does get flooded it will not deteriorate from the experience. This generally means the use of masonry or mineral materials, such as stone, bricks, lightweight concrete, etc. One method of building sustainably that is gaining favor around the world is earthbags. I have an entire website about this (www.earthbagbuilding.com) with lots of information about this technique of building.

Another concept for flood mitigation is shown on this page.

Q: I have 3 lots in downtown Klamath Falls, OR with 3 geothermal wells on it and 42 acres of forest, bedrock & range land. We would like to green build offices & greenhouses for farmers' market/grocery community retail space to lease for our non-profit organizations on the downtown piece & a small farm multifamily dwelling on the 42 acre piece.

Can't seem to put all the information together to build sustainably on either piece & thought your expertise having lived near Ashland could help with site design & architecture & design could help us out. Any heads up you can give us would help.

A: This sounds like some very nice property you have in Klamath Falls! With all of that geothermal potential it would be a shame not to take advantage of it, for space heating, greenhouses, and/or relaxation (if it is hot enough). Klamath Falls is higher than Ashland, and very cold in the winter, as I recall...so the geothermal should be very welcome this time of the year.

There are lots of options for green building, as you know I'm sure, but the first thing is to decide what you need and get some ideas down on paper for what it might look like. I wrote an article about building your dream green home, that might help you with this.

Did you find my site with the stock green home plans: dreamgreenhomes.com?  This might help you think about your options as well. One of the designers (Touson Saryon) at this site lives in Mt. Shasta, not too far from you, and I'm sure he would be interested in helping with your design challenges. He specializes in strawbale plans, but can design for other materials as well.

Q: Is there a certain environment or region that these homes do better in? I really enjoy the earth sheltered home (above ground).

A: You can build an ecological home anywhere in the world. The specific plan needs to suit the climate of the place where you build it though. For instance, a passive solar home needs to be adjusted for the need there is for this kind of heat and the direction of the sunlight.

Q: My dream is to build a natural house, a rammed earth or a cob house.... in Taiwan, as that's where I plan to retire and my husband's family is. In the town, called Taitung, on the east side of the Island. Taiwan's east coast continuously has earthquakes, usually around 4 -6 on the scale. And typhoons which hit the Island's east coast first before traveling onward. Which would be better, rammed earth or cob? Also Taiwan is a sub tropic climate and 3 months of the winter is cold. And there are no furnaces in Asia! Would a natural house be warm enough or warmer than a traditional modern house?

A: From my own perspective, neither rammed earth nor cob would be ideal in a really cold climate, because neither provides insulation against temperature extremes. In fact both cob and rammed earth are nearly the same, with cob being perhaps slightly more insulating because of all the straw that is used to make it.

If you want a truly comfortable home during the entire year, you are better off building the shell of the home with a more insulating material, like cordwood, strawbales, or earthbags filled with volcanic stone or rice hulls. You can use elements of cob or rammed earth on the inside to provide thermal mass. This combined with a good passive solar design should provide a very comfortable home in your climate.

Q: I am doing a project at school to investigate green building design. Our school is currently going to build an performing arts centre along green principles. For our project we have to design a structure or system to be used in the building that is environmentally green, and to conduct an experiment relating to the idea that we have chosen. As part of our project we have to consult an expert in the field. In order to answer my research questions, I did some internet research and selected 5 construction materials. They are conventional clay brick, strawbale, wood, rammed earth and adobe.

1. What environmentally friendly construction materials are the most energy efficient to make and to use in construction?

Adobe uses the least energy to make and utilize in a building. Strawbale is probably next in line in terms of embodied energy. Rammed earth might be next, since it takes a fair amount of energy to ram and often some Portland cement is used to stabilize it. Wood might be next, since there is usually a lot of energy used to harvest, mill, and transport wood. Conventional clay bricks use a lot of energy to fire and transport.

2. Which construction materials would keep the building the coolest, thus saving the energy that would be used to cool the building?

Strawbale is undoubtedly the winner here. Wood would be next, since it is a moderate insulating material. The other three are about tied, since all of them are really "thermal mass" materials and are poor insulators.

But the real answer to this questions is that the best solution is a hybrid of several of these, so that the shell of the building insulates the structure, while some thermal mass material is incorporated inside the house to keep it at a constant temperature.

Q: I live in Springfield Missouri. I hope to buy some land on Table Rock Lake. I want to build my retirement house there over-looking the lake. I want to go sustainable. Can you give me an idea of which type of home you would recommend for my environment here? The weather changes can be quite dramatic & summers are hot & humid. I'm trying to weigh all my options & get an idea of what the building cost in general would be for these type homes!

A: Appropriate housing for hot, humid climates, is a tricky consideration. I just posted a long article about this at here, where the advice for such tropical regions is generally to use only very light-weight materials and enhance all possible ventilation. This advice is good when it is hot and humid most of the time, which is not the case in Missouri, since you also have a cold winter season. Uninsulated homes in your climate will be very uncomfortable for much of the year. The above guide also suggests that earthen materials handle the heat and humidity much better than dense concrete, stone or brick, because it can absorb and release the humidity better and is not as likely to form condensation and promote mold. Going with this suggestion, you might consider adobe, rammed earth, cob, or earthbag construction.

But then you would also need some insulating material (preferably on the outside) to keep the structure from getting too cold in the winter. I know that strawbale homes have been successfully built in your region, but there is always the concern that some detail of the construction will fail, and with it an entire wall if the straw gets wet.

I have often thought that earth-sheltered or underground homes would do well in hot and humid areas, although I do not have personal experience with this. The earth would certainly buffer the heat from outside, but there is the danger of condensation if the walls are solid concrete. To avoid this, using earthbags filled with either soil or crushed volcanic stone would likely work well (see www.earthbagbuilding.com ). Another option here would be to use insulated concrete forms (ICFs), which isolate the walls with insulation (see this page); there are several of these manufactured with more sustainable materials.

So it is hard to give a simple answer, but these are some guidelines to consider.

Q: I am from New Orleans. I moved to Houston after Hurricane Katrina. My house has been siting to this date waiting for me to start work. I recently obtained some money to allow me to start the rebuilding. I would like to remodel and make my house energy efficient. I also would like to start an organization that helps others like myself who have little experience in construction and do not want to hire a contractor yet would like to rethink the way they rebuild their homes in New Orleans. I am moving slow because I need to find out where I am going. I wanted to know if you had any advice

A: I do have advice for people who want to rebuild in New Orleans, but most people won't want to hear it: Don't do it, because the city is simply too vulnerable to future disasters of a similar nature, especially with rising temperatures and sea levels. Find a safer place to build. But if you do decide to rebuild there, do so with techniques and materials that will not be so badly harmed by inundation with water, such as with masonry materials.

Q: Do you have any feedback on Maui Hawaii as a place for a sustainable lifestyle?

A: I asked my sister, Molly, who lives in Hawaii, to provide some feedback. Here is what she says:

"The sustainability issue in Hawaii is a mixed bag.  The tropical climate allows one to live a lifestyle where housing needs are simpler, with smaller and more open covered spaces, however, building materials are quite a bit more expensive.  There is sufficient sunshine in most areas to make solar power a viable option, in fact there are areas here on the Big Island where alternative power is prevalent.  Heat is only needed at higher elevations, but our grid electricity is fairly expensive.  Phones and internet service fees are on a par with the mainland. Anything imported is pricey, including fuel and packaged foods.  If you plan to live simply, as I do, eating local produce and growing some of your own food, you can live reasonably."

Q: My wife & I own 10 acres in the mountains just north of Asheville, NC--and want to build (with reasonable cost) a green, self-sustainable house. We love the idea of a timber frame with cob, cordwood or SIP's as infill, but are not sure if this is best in our "temperate zone rainforest" weather. Can you give us any advice for this climate and humidity.

A: All  of the building methods that you mention have been used successfully in the Asheville area. Cob is not as insulating as the other two, but that may not be so much of an issue there. If you have enough appropriate wood for a cordwood structure, that might be the most comfortable and ecological choice.

Q: Select Contracts is a Design, Build and Operate company based in Dubai specializing in international leisure and entertainment projects. One particular sector is the Hotel industry and I am currently trying to convince my CEO that alternative building techniques are financially viable and fantastic for the environment! All buildings in Dubai are air conditioned; is there a sustainable alternative?

A: I can give you some general guidelines for efficiency with air conditioning: 1) Evaporative coolers in arid regions use way less energy than conventional air conditioning units. 2) Carefully design solar inputs (glazing) to avoid the buildup of unwanted heat. 3) Utilize thermal mass materials inside the structure to help maintain constant temperatures. 4) Where feasible, dig into the ground or berm structures to help isolate them from the ambient heat. 5) Take advantage of wind scoops that are commonly used in the Middle East to help cool homes. 6) Position pools of water so that the wind carries cooled air into the structure. 7) Make sure that the shell of the structure is very well insulated.

Q: I am a graduate student at UC Denver studying architecture. We have a project in studio, which may actually have funding, that is an orphanage in northern Mexico. We have been asked to incorporate sustainable design into the project, but have little information about what aspects of sustainable design would work in this geography.

A: The climate of the desert region of Northern Mexico is similar to that of New Mexico, with hot summer days that cool off at night, cold winters, but with lots of sunshine...and quite arid. The available native building materials are mainly adobe soil, with limited stones and wood. Current building practices there favor fired brick or concrete blocks, with steel vigas to support flat roofs covered in concrete.

The old-fashioned thick-walled adobe homes built in Mexico and the Southwestern US actually were fairly comfortable because they were thick enough that the heat of the day would not penetrate inside until night time, when it would be more welcome. Unfortunately, the Mexican people often dislike adobe because it is considered too old-fashioned.

A modern passive solar home, with insulated walls that have plenty of thermal mass on the inside, and south-facing glass that is shaded to collect only the winter sun should function quite nicely in that climate. There have been some attempts at building strawbale homes in that region, but while they perform well, they have not caught on much with the locals. It is always a sensitive thing designing or building outside your culture.

Q: How much benefit does passive solar design, insulation, thermal mass provide in Mexico, where the climate is milder than the U.S.?

A: Most homes in Mexico these days are just relatively thin-walled brick or concrete block construction, which provides thermal mass but no insulation. These buildings can be fairly comfortable in the right climate, such as around Lake Chapala where the annual temperature range is moderate. In many other areas of Mexico, such construction leads to both over-heated and too-cold homes much of the time. The older thick-walled adobe buildings are actually more comfortable, staying cooler in the summer and warmer in the winter than modern construction.

Q: What is the optimal climate for building a house using either adobe bricks, cob or earthbag?

A: Both adobe and cob are blends of clay and sand (with the possible addition of straw)...and so is earthbag if that is what you fill them with. These are thermal mass materials rather than insulating, so they are ideal on their own only in climates that are relatively mild, without extremes of heat or cold. Earthbags can be filled with other, more insulating materials (such as crushed volcanic stone, or rice hulls) which are insulating, so this can be more comfortable in a wider variety of climates.

Q: Which states/areas of the US are generally friendly to alternative building/living in terms of logistics and in offering favorable climatic conditions for earthen homes, materials readily available on the land, and affordable land?

A: The American Southwest has seen more alternative building than many other regions, so it might be easier to build here. For instance New Mexico has specific codes for adobe homes. Also this desert region can be a good climate for adobe building because of the sunny weather and cooler nights.

Q: One of my dreams is to start a large eco-village/Commune. Id like it to be all green and, well, choosing the right material is very difficult. A part of my dream is to have it located in Alaska and from what I've been able to tell, that can cause many issues. Alaska has a very wet and moist climate.

A: Alaska does indeed present many challenges for building, and obviously one of the main ones is the climate, especially the cold. This means that any house needs to be very well insulated to be comfortable. Another challenge is availability of appropriate materials. So what kinds of natural insulating might be available to build with? I doubt that there is much straw or rice hulls locally. What about lightweight volcanic stone? Pumice and scoria, as well as perlite and vermiculite, can be used to fill polypropylene bags to build with. You might take a look at www.earthbagbuilding.com to see the huge variety of home styles that can be built with this method.

Well another problem though, which just came to mind, is earthquakes or volcanic eruption. I've thought about using granite. Similar to how the the Inca used to build their shelters and cities. Its all very confusing.

Granite is not going to keep you very warm. Earthbag buildings can be reinforced in ways that protect them from collapse in earthquakes. Our website www.earthbagstructures.com is mostly about this.

Q: I am a US architect working on a project in Lesotho. A local has an earth/cement block making machine (solid blocks) 10.3x30.6x20.5cm. The typical contemporary solution is double width bricks with a 20cm insulated cavity. The traditional structures are thick stone, and where crude stonework they have earth or "stucco" coverings. I'm trying to use the blocks with a brick exterior and 1.5cm plaster interior finish. Am I nuts? Is the insulated layer unnecessary?

A: I would expect in that climate that the insulated cavity is essential for comfort in an otherwise completely thermal mass shell. A stucco finish over the bricks should work fine.

Q: I've been following The Year of Mud cob house blog for 2-3 years. Basically, he's learned the hard way that cob is not a good choice in cold climates: small-scale.net/yearofmud I found myself thinking "why wasn't he warned?"

A: Yes, I have also been following this blog for awhile now. In fact Michael G. Smith and that fellow have been having a very long and detailed discourse about his problems, trying to figure out exactly what it is. At this point I think they feel that it is a combination of condensation from the cold wall and rising moisture from the ground. It has been very frustrating and sad. Michael actually suggested that he move out for the winter until things warm up. We have been warning people for years at GHB that some earthen building techniques are just not appropriate for cold climates.

Q: I live in south Alabama & am interested in natural building. What are my best options for building materials & finishes in an area with long summers & high humidity?

A: I just looked on the chart of ground temperatures for Alabama and it appears that you can expect a steady temperature of about 70 degrees F. in the southern region of the state. That is a very comfortable living temperature, so my recommendation would to find a place where you can dig into the ground to take advantage of this fact.

Good materials for earth sheltered building include natural stone, earthbags, used bricks...anything that won't decompose if in contact with the soil. And earthen plasters are excellent for regions of high humidity because their ability to absorb humidity without harm.

Q: We plan on buying 10-50 acres of land in either PA, Maryland, or Virginia.What form of construction & insulation would be best for the PA/Virginia climate? (strawbale, or earthbag perhaps filled with perlite, or?..)

A: You definitely want a well insulated house in that region of the country, and either strawbale or earthbags filled with perlite could provide this. Another option you might consider is cordwood masonry, and with that much land you might be able to supply the wood needed from what is available on the property.

Q: Is it possible for an earthbag home to use geothermal energy?

A: Sure, you can use geothermal energy with practically any kind of construction, although generally you want a well-insulated house to take advantage of geothermal's efficiency. Earthbag houses can be insulated in a variety of ways.

Q: My husband and I have a 250+ hectare property here in Ecuador, next to a national cloud forest. We are looking to build a home there and we're struggling to decide what kind of home might work best in the climate there, which can be very changeable - warm, very sunny, then cold, windy rainy. It's high elevation with lots of natural springs/moisture. We've been considering lots of options from adobe to earthbags to Monolithic domes. Do you have some guidance on what might work best in that kind of climate to avoid mold etc?

A: A well-designed passive solar home that has good insulation and interior thermal mass should help with the temperature fluctuations. Some windows that collect sunlight during the cold times can be used, but you don't want to overdo this in that climate, and if they can be shaded when you don't want the extra heat, that would be good.

Earthen plasters or adobe on the inside are good for both thermal mass and mitigating high humidity. For the outside shell of the house, use insulating materials that are not vulnerable to rot or mold, such as earthbags filled with lightweight volcanic stone, lightweight concrete, or various foam products. Monolithic Domes do satisfy some of these requirements.

Q: I am dreaming of building a natural home. We live in northern Virginia, so we have all four seasons. The temperature ranges from single digit Fahrenheit to triple digit Fahrenheit. We have rain & snow (sometimes LOTS of it). Summers are very hot. What kind of building materials would be secure, comfortable, and sustainable?

A: Appropriate materials is more a matter of design than local climate; it all has too work together: design/materials/climate. Most well designed passive solar homes should perform quite well in your climate. You might read an article that I wrote about this awhile ago.

Q: Recently Oklahoma was devastated by a large tornado. I was wondering if there were any structures, at low cost, or ideas for those living in territories such as Kansas, Oklahoma, and the rest of the tornado belt, .that would assure survival of the humans and the structure....at least the humans?

A: Yes, there are tornado proof buildings, some at fairly low cost. I'll list a few designs that should do the job:

Q: I'm an artist/architect living in Memphis, TN. I'm thinking of building an art studio. I'm wondering which type of alternative house construction makes the most sense here? It's very hot and humid in the summer, with 90 percent humidity. In the winter it is cold and humid, biting cold. Spring and Fall are pleasant. Rammed earth and earth based construction might have issues with humidity, I can imagine condensation occurring. I think timber construction might make the most sense.

A: Actually earthen construction can handle humidity better than you might expect. Tests have shown that thick earthen plasters, adobe, rammed earth, etc. are able to absorb and moderate interior humidity naturally, without degrading. I noticed that the general underground temperature in Memphis is about 63 degree F. so this is another possibility--to dig into the ground or berm the structure to take advantage of the buffering effect of the earth.

Q: I am the mom to 7 and the wife to a disabled veteran. My husband and I bought 20 acres of raw forest in central Alabama many years ago. This was to become our home one day. We lived in a rental home with the hopes of when he returned from his tours we would be able to build our dream home. Three months after he returned to me, our uninsured rental home was hit by a tornado. We lost everything. With no where to go, we lived for months in hotels. After all our savings was used up we had no choice but to move to our 20 acres in the woods. With no utilities or structures we moved. Me, a wheelchair bound husband and my babies. The kids and I made tents with tarps and trees. We drew water from a creek near by and cooked over fire. Not at all ideal but we had nowhere else to go and my husband would rather die than take a hand out. I managed to save some and bought a junker mobile home destined to go to scrap. 2 bedrooms and a bathroom. The kitchen had been torn out and the wiring is crazy. We have tried to make this as good as we can. I either need to add on to this sad mobile home or I need to build a new structure all together. I have the issues of hot humid climate of Alabama, and time, frankly. I can't take years to build a decent home. What would be the most effective method for my money, time and climate?

A: I empathize with your life situation; at least you are resourceful! The mobile home sounds like a disaster, but it is a roof over your family's head for the time being. Unfortunately there is no really easy way to create a substantial house, although some approaches are easier than others. You have great fortune in owning property in a location with a benign climate. In fact I noticed that if you dig several feet into the ground in Alabama, you will discover year-round temperatures of between 65 and 70 degrees F. This is almost perfect for human comfort, so my suggestion is to dig into the ground for your home. You can use earthbags filled with the very soil that you dig out to make the walls. Put those kids to work to help you.

Q: We live in Alabama where for about 9 months out of the year it's extremely hot & humid (temps above 90) & then the remaining 3 months are either breezy & nice or extremely cold. It rains about 57 inches a year & we do have the occasional tornado. What type of building would you suggest is best? And we're on a tight budget of about $2600. Earthbag? Cob? Strawbale? Combination of any of these? How do we protect the house from moisture without using cement or chemicals? We're leaning towards a small house of about 300 sq feet with a possible loft if there's an affordable way to make it work. We've got dozens of pine trees on our land so is there a way to cut those down & use them for any lumber needs? Or does it take a long time for them to dry & be treated?

A: Depending on where you are in Alabama, the stable underground temperature year round is between 65 and 70 degrees F. This is not far from a comfortable living temperature, so I would advise you to consider underground house designs. The simplest and least costly building technique for doing this is using earthbags, which could be filled with the native soil, and then plastered on the inside with earthen plaster. This combination should handle the humidity in your region very well. The seasoned pine could be used for various parts of the structure as well, so consider this in your plan.

What do we need to do in order to be able to use the trees?

It is best to allow fresh cut trees to dry out before they are used in construction because they shrink some as they dry, and this might take up to a year. In some circumstances green wood can be used if the shrinkage is not a problem. You can use the debarked logs as rafters or supports for roofs, as lintels over doors and windows, as interior decoration, etc.

And what kind of roof would be best?

Again this depends on the design, but if it is to support a lot of weight, like a few feet of soil, it needs to be very sturdy. This can be done with large diameter logs used as vigas, or with reinforced concrete (much more expensive).

Q: I am interested in building in Ecuador. Please show me what is conducive to this area, organic, healthy to live in.

A: The climate of Ecuador is temperate, with average temperatures close to comfortable living temperatures much of the time. So you don't really need much insulation or heating and cooling strategies to be comfortable. It is mostly a matter of keeping the weather at bay...rain, wind, etc. Most any decent house can do this, but you don't need to focus so much on passive solar ideas, like many of the designs shown on my website. I would look to using native materials for building, like bamboo or earthen materials. If you are in the highlands, where it can get cool at night, you might want more insulation and a bit of passive solar to even out the temperatures from day to night.

Q: I have always held the idea of building a new home someday erected into a mountain,mMaybe 20-30% at best. Would this have any long term savings?

A: It is almost always beneficial to dig into the earth to shelter a home because it provides great thermal protection and reduced overall energy needs to heat or cool a house.

Q: I'm a single 52 year old woman living very remote and will have no help in building my home. I have LOTS of time, endurance and perseverance, but a sensitive back that I must be a bit careful with...no heavy lifting. Can you suggest which natural building technique might suit me best? I can likely afford most building supply options (not over $9,000) My climate is southern Missouri.

A: Most building techniques do require some fairly heavy lifting, at least at times. I noticed that the underground temperatures in Missouri are in the high 50 degrees, so some sort of underground home might be pretty comfortable with just a bit of passive solar input to raise the temperature in the winter. This can be done with earthbags, and you could possibly have the site excavated in advance so you wouldn't have to do too much digging. Then the bags can be filled in place with just small buckets of soil. See www.earthbagbuilding.com for more about this. One nice thing about this is that it can be done very cheaply.

Q: We live in An Duang Tuek, Cambodia. Our house is very old, like me. Maybe 70+. It is difficult to walk. What are the pros and cons of building a house up off the ground compared to building a house on or below the ground ?

A: Usually raised houses are built to avoid periodic floods or certain vermin. Also they can take advantage of winds to help cool them in hot climates. Houses at ground level are easier to enter and can be bermed with earth to help moderate temperatures. Various measures can help avoid problems with flooding. Underground homes can be the most efficient in any climate, but care must be taken to avoid flood damage where this is a concern.

Q: I have been looking into building a cob style art studio on my acreage in Norman Oklahoma. However, as I am reading some of this I am not sure which is the best natural building style to use for my area. Due to fracking earthquakes have become more of a concern in Oklahoma than before, tornados are always an issue as well as generally strong winds. Geographically Oklahoma is known for being one of extremes in climate -- we get very cold, very hot, severe storms, raging floods, wild fires, earthquakes, strong straight line winds and gusts.

A: In that climate with such extremes cob would probably not be your best choice, since it doesn't provide very good insulation. If I were to build in that situation I would seriously consider going underground, or at least substantially bermed. The constant underground temperature in that region is about 62 degrees F., so you would only need to raise that about 10 degrees to be very comfortable year round. Building underground can be done with earthbags for the wall fairly easily and inexpensively. You would still want to put a bit of insulation on the outside of the walls, but you wouldn't need much.

Q: I am an undergraduate civil engineering student completing research for an interest paper. My paper will be covering the benefits and drawbacks of berming vs subterranean builds for residences in the dessert southwest. (Greater Phoenix Metropolitan Area) What is the primary resistance from the market. (Why in the heck aren't builders already building this way in areas like the dessert southwest.)

A: I've been wondering the same thing for many years. I have some property in Southern New Mexico where underground housing would make so much sense in terms of thermal comfort and efficiency, but you rarely see this happening. I even built a small underground dome with earthbags to witness the effect first hand. I consider berming and total earth-sheltering to be similar, just different degrees of the same thing, with similar benefits. I think that the primary resistance to this approach to housing is really cultural; people are just not used to it.

Q: Please could you advise me on the most suitable plans for building a permanent structure in a rural part of Jamaica. I would like to build a 1 or 2 bedroom property which is self sufficient, meaning I would like to use electrical appliances and have hot water.  I want to have plumbed services and collect my own water.  Is this wish achievable using the Earth Bag system of building in this region of the Caribbean.

A: Yes, I think that earthbags would be a good choice for building in Jamaica because they are very robust in all kinds of weather. I suggest that you consider an underground plan (especially if the water table isn't too high  where you build). This would allow you to take advantage of the cooler temperatures below ground and avoid needing to supply heat or air conditioning perhaps. There are some plans for this type of housing shown at dreamgreenhomes.com. Some of these are designed for rainwater catchment and solar electric panels, but these amenities can be added to most any design. Some of the designs might need to be changed to reduce the passive solar heating potential because the need for this in Jamaica is less.

Q: I want to know if it is possible to build an underground mud house in Africa (which is a humid environment) and can generate cool temperature inside. Also I would like to know if it possible to use a steel container underground and plaster it round with mud. Would this also generate a cool temperature?

A: My suggestion for building underground in Africa, or most anyplace, actually, is to use earthbags. These can be filled with the local soil and if they are out of sunlight they last a very long time. You can plaster them on the inside with earthen plaster and they can help control humidity. The outside can be lined with plastic to keep water from coming through. I have a whole website about them: www.earthbagbuilding.com. You might be able to bury a steel container as well, but there is always the potential that it would rust. Either of these options would create a steady cooler space than above ground housing.

Q: I am working on a design for a structure that I can best described as a fusion of a straw bale home and a yurt. My mission is to make these structures hurricane, flood, fire resistant and affordable. There are so many people in need of housing that fill these needs. What do you think of this?

A: When you say that you are considering a strawbale yurt-like structure that is resistant to hurricane, flood and fire, I immediately think of the general incompatibility of straw in flooding conditions; it simply can't survive being soaked in water like that. The yurt shape and design is generally very robust under most conditions. Have you considered earthbags as a technique for building? This method has the potential to resist all forms of catastrophes, even earthquakes, as was recently demonstrated in Nepal. I have a website that is devoted to earthbag building: www.earthbagbuilding.com

Q: I am living in Rishikesh, India running an institution for yoga. I have been planning a sustainable eco ashram for a long time. In the meanwhile i am researching alternatives for constructing and earthbag buildings have taken a lot of attention. It's a mountain terrain with slopes;. the altitude is 800 mts approx. We have around 5 seasons a year; summer high temp is around 45 degrees; monsoon is for 3 months altogether and it rains heavy. Winter low temp is around 4 to 5 degree (midnight); the soil quality is good, as its a fertile area. If we decide to build the ashram with earthbag technique, will it be a feasible idea, keeping in mind the seasonal variation? Also I want to make sure that the construction is durable as its a big investment. We are planning on to make a housing community for at least 20 people, so it will be in total around 10 cottages. My concern is especially the monsoon as dampening and leakage is a big problem in most of the buildings here. I am studying about the thermal mass and insulation, but cannot find some real information on water leaking situations. i am seeking your wisdom on these issues.

A: According to the temperature variation that you quote, the average year-round temperature is around 25 C. This is likely the stable temperature below ground there, which means that if you were to build underground, or at least substantial berm soil around most of the walls, then you would have a very nice living temperature without air conditioning or heat. Earthbags lend themselves to underground building very well. To deal with all of the moisture you need to carefully design the roofs and the drainage around the building to keep the moisture away from the walls as much as possible. This type of building can be extremely durable.

Q: I am in Missouri where it has four seasons and summers hot and winters cold. What kind of insulation and Hvac system would you recommend?

A: It depends on the design and the materials used which form of insulation might be best. Passive solar heating and cooling is preferred for comfort and low energy consumption. Back-up ground source heat pumps can be a good option.

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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.