On a community level, shelter takes the form of building codes, zoning, and community planning.   Restrictions may include style, size, building materials, standards of maintenance, external appearance, fencing, color schemes, type of plantings, etc. Each village can have it’s own architecture, type of building materials and village layout, to which everyone in the village must agree. A large brick home next to a small adobe cottage might not be aesthetically pleasing.

A house costs far more than an acre of land. Therefore we are interested in less expensive housing. The more money that is needed up front, the more restrictive we become in our community membership, and the longer it takes people to pay off potential mortgages by working in the city. This is counter-productive to the purpose of the community. Nor are we interested in huge houses so we can disappear inside to interact only with a TV or computer. Privacy is important, but we’re also trying to be a model of simple living and high thinking, without taking more space than we need. The maximum single-family home size is 2000 square feet. Our ecological footprint is an important consideration. There are better things to do with money than have a lot of unnecessary square footage, and the space could also be used for better purposes. 

There are many methods of earthen construction. Below are some types that we consider to be superior.  

 

Earthbag (sometimes called sandbag) is a fairly recent addition to earthen construction types. As with all the other types, local soil is used, but this type of construction is very forgiving in the soil mix. Different fills can also be used to achieve either better insulation or thermal mass. Many people use Earthbag walls and wooden beam roofs, but some use earthbags exclusively, thus building a dome. The bags are woven poly and can be purchased new or recycled. Stucco or plaster must be used on walls to protect the bags from sunlight. (Link 1) (Link 2)

Cob is one of the oldest of building materials. Cob houses in Europe still exist that are hundreds of years old. Walls are hand-made out of mud mixed with straw, one handful (cob) at a time. There is no limit to the artistry that this style allows, and every home is unique and custom-built. Few are as traditional as the one on the right. Cob is not used for roofs, which are generally a more traditional type such as wood frame or bamboo with shingles or thatch. As with many earthen types, cob houses can easily be repaired or reshaped and building them is usually a community event.  This site has a lot of information and pictures.

Rammed Earth has also been around a long time. The walls are built by using large forms (usually plywood) for both sides of the walls, and then compacting earth in layers inside the forms. They are also made from local earth like cob, and sometimes require some clay, sand, or a bonding material added to the soil. R.E. homes will always have perpendicular walls so they look more typical than many cob homes. They are very solid, and because they are usually very thick provide tremendous thermal mass. R.E. is sufficiently strong for multiple story buildings. Like cob, extended exposure to water is damaging so they have overhanging roofs, and are often covered with a plaster on the exterior. (Pictures and more pictures.)

Compressed Earth Block (CEB) construction is similar to concrete block, but the blocks are made by compressing the local earth by machine or by a manual hand-operated press. They are made right at the construction site and can be in different sizes. They can be used in multiple rows for greater thicknesses, so can achieve the same thermal mass of rammed earth, but construction is much faster, especially if blocks are made with a machine, or pre-made with a hand press on site prior to construction.  This site has a lot of information including videos and CEB machines.

Here is a site that covers various types of natural construction.

Wood frame houses are not desirable as they are prone to termites, carpenter ants, other pests, and wood rot. They are also very prone to hurricane and tornado damage, and have very poor insulation. Wood is no longer considered a renewable resource as forests are gradually shrinking. It is especially used because homes can be built much more quickly than earthen type homes, but homes made of earthen materials are used in most of the world. Wood may need to be used in roofing structures in many cases, but termites and wood rot are much less of a problem since it is high off the ground. Instead of wood, bamboo can be used, as it grows quickly, and can be grown in contained patches for use as a building material. Furniture and utensils can also be constructed of bamboo, and it is an excellent repair material for many purposes.

Straw bale construction is another viable method.  It is not our first choice, as it is very unforgiving with any amount of moisture in the construction phase and must be completely sealed (with stucco) after construction. If water gets into a straw bale wall it can be very troublesome. It is very suited to drier climates. Some straw bale builders have been turning to wood frame with straw bale infill. The primary advantage to straw bale is the superior insulation provided, and it is more suited to colder climates than structures that use only earth. 

Cob and Rammed Earth are excellent, but are more labor-intensive.  They are good methods as long as labor costs and time are not a significant factor. Most earthen construction methods are significantly more labor intensive than wood-framed houses, but they are far superior in every other way. In particular, earthen walls provide excellent thermal mass, and thicker walls increase the thermal mass. Earthen homes also breathe, so the walls will not wick water, as opposed to concrete. 

For the very best thermal mass, and therefore efficiency in a temperate climate, our choice is Rammed Earth.  However, Compressed Earth Block methods can be used to make walls equally as thick, so either of these are excellent. (Cob can also be used for very thick walls.) If designed properly, homes in the southern US can be constructed with thick walls that would require little or no heating or cooling. The cost of materials is almost as much as a wood-framed house, but the labor is far greater. Keep in mind that the walls only comprise around 10% of the total cost of a home.

For the best overall, our choice is Compressed Earth Block.  Construction time with CEB is very fast if the blocks were previously made, which is required if a stabilizer is used - and the use of a stabilizer is highly recommended. CEB can be used for multiple stories, as can Rammed Earth. However, only CEB, straw bale, and Earthbag can be used for roofs. CEB and Rammed Earth both have code in New Mexico, and in Texas that code is usually adopted for use by the local officials.

We will be purchasing or renting a hydraulic CEB machine and making tens of thousands of good quality blocks, which can then be used for all the buildings in a community as they are gradually constructed. We will also purchase a manual CEB press so that future fuel shortages will not stop necessary construction. 

Machines can be used in all these earthen construction methods to speed up the work. There are Earthbag machines that will fill the bags. Pneumatic tampers are used in Rammed Earth. Heavy equipment can be used to mix Cob, and it can be placed on thick walls with a loader. 

For the greenest method of all, Cob is definitely the winner. It requires nothing but your hands, local dirt, water, and straw. All the others need some type of forms. 

Both wood frame and earthen construction methods can use the same types of windows, utilities, doors, and roofing materials. The difference in materials cost and length of construction time is primarily related to the walls.The only exception to this is if earthen roofs are constructed as above.

The temperature year-round in the Southern US can vary from 20 degrees to 105 degrees. Using very green building methods and design can greatly reduce the need for heating or cooling, but will not usually eliminate it.