Natural building
involves a range of building systems and materials and places major emphases on sustainability, durability and the use of minimally-processed, plentiful or renewable natural materials, as well as those which, while recycled or salvaged, produce healthy living environments and maintain indoor air quality. It is a general term, interpreted slightly differently by each of its typically self-directed practitioners.
The need to lessen the environmental impacts of housing and other buildings, while promoting comfortable, healthy, aesthetically pleasing and spiritually uplifting structures, is the basis of natural building. To be more sustainable, natural building uses primarily abundantly-available, renewable, reused or recycled materials. The use of rapidly renewable materials is increasingly a focus. An emphasis on building compactly and minimizing eco-footprint is common, as are on-site handling of energy acquisition, on-site water capture, sewage treatment and water reuse.
Natural builders emphasize simple, easy-to-learn techniques and depends mainly on human labor.
The term cob is used for a building system based on a mixture of clay, sand and straw, that uses no forms. Cob is one of the simplest and least expensive building techniques available, though typically very labor-intensive. Its other great advantage is its versatility. It can easily be shaped into any form making it the perfect artisic media for a soul nourishin home.
One of the oldest building methods, adobe is simply earth mixed with water. Sometimes chopped straw or other fibers are added for strength. The mixture is then allowed to dry in the desired shape. Usually adobe is shaped into bricks that can be stacked to form walls.
This building method utilizes stacked polypropylene or natural-fiber (burlap) bags filled with earth. The materials of war – sandbags and barbed wire – are used for peaceful ends, integrating traditional earth architecture with contemporary global safety requirements. The system employs the timeless forms of arches, domes and vaults to create a shell structures that is both strong and aesthetically pleasing.
Straw-bale construction is a building method that uses straw bales as structural elements, insulation, or both. Straw bale building typically consists of stacking a series of rows of bales on a raised footing or foundation. Straw Bale construction has over 100 years experience in America. Recently many new and efficient homes have been built with bales of straw.
The basic earthship design incorporates substantially bermed, passive solar architecture. The primary retaining walls are constructed with used tires, filled with earth and stacked up like bricks. The interior surface of the tires is then plastered with adobe or cement so the tires don't normally show. Earthships often employ many ecological concepts, such as water catchment from the roof, reuse of greywater, composting toilets, indoor gardening, etc.