Earthbag homes

An earthbag home is a home built out of bags of earth, stacked in certain patterns and on a solid foundation. They utilize local resources such as sand, gravel, scoria, which is volcanic rock, rice hulls etc as raw materials. Wood is avoided to avoid further depletion of forests and instead use such things as balustrades, stairs and railings.

Why should I be aware of this?

Earthbag home is a movement to move back more closely to the earth, and to use renewable resources and resources readily available for building homes. Recent studies and experiments have proven that an earthbag home is environmentally friendly, energy efficient, and is built from local - and readily available - resources.

All about Earthbag homes

Earthbag homes involves filling up burlap bags or polypropylene bags with earth. Clay is mixed with a certain percentage of sand, stapled tightly shut, and stacked to build the outside walls of the home. As wood is not used, a dome is often incorporated into the design so that rafters do not need to be put in place.

Typically arched doors and round windows are made, incorporating into the design. Sometimes, a door is framed in using lumber. A number of houses have window openings made of metal farm machine wheels and culvert couplings. The outside is usually covered with stucco, papercrete, or stabilized earthen plaster. In several houses an airlock is incorporated into the design to be more energy efficient. This serves dual purpose - the main door opens onto a room that can be used to store coats and boots, and then egress is made into the interior.

Energy efficient homes

Because of the thick walls and the insulating qualities of earth, these homes make good use of passive solar heat, facing south or east, depending on location. The sunlight is absorbed by the interior walls, keeping the room warm after the sun goes down. Often, the only source of energy used is either fireplaces or small propane or electric heaters in individual bedrooms. The exterior walls of the house should be properly finished so that the daily heat from the sun does not leak back out in the evening.

Disadvantages

• The designs of Earthbag homes look heavy to some and give the impression of living in caves.
• The houses also require a great deal of plaster in construction to insure water integrity.
• Material used to fill the earth bags needs to be stable and not contain moisture.
• A small mixture of cement into the bags can give increased stability, depending on the composition of the filler.
• Some people find the design of an Earthbag home to be "heavy" and have the feeling of living in a cave.
• Before you plan to build an Earthbag house be sure to check local codes and work closely with local building officials.

What can I do about it?

• Materials for building an Earthbag homes are literally right in your own backyard.
• The topsoil should not be used as grasses, twigs and the miscellaneous debris found in topsoil will eventually decompose, leaving cavities in the bag. This will and undermining the structural integrity of the building.
• Once cleared, the remaining clean soil can be used. You can also import soil from a local gravel yard, where reject materials from gravel usually have an appropriate sand-to-clay ratio.

CopperBytes

• Earthbag homes are inexpensive, with many builders able to use the soil that's on-site to build the home
• Soil is made up of clay, silt, sand and gravel.
• Bags are usually low-priced in bulk, particularly misprinted bags that companies sell at reduced rates
• While Earthbag structures are labor-intensive, they are relatively easy to build with little experience and a crew of only a few people
• Earthbag homes have more monolithic structures, meaning that the entire structure is made from the same materials throughout.
• Earthbag walls also exhibit high levels of thermal mass, which is the measure of a material's ability to absorb, store and transfer heat
• Earthbag homes also appear to be structurally sound and safe.

References:

• Building an Earth Bag Home
• How Earthbag Homes Work