Solar Energy Facts for Homebuilders

For a person who is interested in building an energy efficient home in these times of rising costs, including energy costs, the amount of information is daunting if not downright scary. We'll try to pare the information down to something manageable by looking at some of the ways we can build and keep our energy demands under control. Our solar energy facts give us a number of options:
-Conventional structure-stick and wood
-Earth bermed-using earth for a moderator
-Rammed earth
-Rammed earth blocks
-Adobe
-Straw
-Earthbag

An energy efficient conventional house can cost anywhere from around sixty thousand to more than two hundred thousand dollars, depending on how much energy you, yourself are willing to invest. One thing to bear in mind-how much skill do you have for this kind of project? To build a successful energy saving house of this sort would require super insulation, photovoltaic or wind power, and solar hot water, as well as some form of space heating.

A well designed earth bermed structure has only minimal needs for space heating. I've seen many options for this including wood stove, baseboard heating, and European tile stoves. Combined with solar hot water and either photovoltaic or wind energy, this is an excellent way to go, and is adaptable to any climate. I've seen costs for this type of construction from the seventy thousands to over two hundred thousand.

Rammed earth is a viable concept probably only if you are prepared to do a tremendous amount of physical labor, or you have laborers available. This method involves using forms between which dirt is compacted layer after layer until reaching the desired height. If you are really interested in this process, I recommend two books, Comfort in Any Climate, by Michael Reynolds-Solar Survival Press; and The Rammed Earth House, by David Easton-Real Goods Press.

One of my favorite choices is rammed earth blocks. This concept was developed several decades ago in Columbia with the invention of the
cinva block ram. This is a mechanical device with a long handle with which one can compress soil to about half its former volume. With the right mixture of soil, water, and about 3% Portland cement, we can make earthen blocks that are very tough, strong, and cheap-really excellent building materials. These blocks are a product that can be pretty much used anywhere in the world.

Adobe is another of our prime choices, according to our solar energy facts. Some people might think adobe construction might be limited to our southwest, but for a slightly higher cost adobe bricks can be stabilised using either 3 to 6% asphalt emulsion or 5 to 10% Portland cement. There is a strong customer demand for adobe. In New Mexico half of all new homes selling for more than $300,000. incorporate some form of earthen construction. Most are adobe, but some of them are using new earthen technology.

In the last few years, building with straw bales has become very popular as a means of keeping costs down and providing a great deal of insulation. There are many good designs to choose from and this is another method of construction that is usable anywhere in the country, as long as one can locate the straw at a good price. This method of construction either uses the structural integrity of the stacked bales, themselves, or a post and beam construction with the bales just used as walls and insulation. Either scheme requires that the bales be stuccoed inside and out. This type of housing can be very cost effective with the proper design.

One method of construction that has gained a certain popularity in recent years is called earthbag construction. Basically it consists of polyester bags, filled with soil and stacked according to the design. The bags are nearly always stacked in circular patterns so as to achieve a certain rigidity. Barbed wire is laid between the courses to give strength to the structure. Plaster is applied to the outside to provide waterproofing. Solar energy facts assure us that this is a legitimate form of construction and seriously to be considered.

These are some of the main options we have when considering building with energy efficiency in mind. Before any kind of choice is made, the prospective builder needs to consider climate and land considerations. Size is another thing to think about because the smaller a structure is, the less energy it will require. The proper preparation for a venture of this sort will certainly make the outcome more satisfying; so, the more research, the better.