Natural building
[1] This in turn implies durability and the use of minimally processed, plentiful or renewable resources, as well as those that, while recycled or salvaged, produce healthy living environments and maintain indoor air quality.
As Michael G. Smith observes, it depends on "local ecology, geology and climate; on the character of the particular building site, and on the needs and personalities of the builders and users.
The orientation of a building, the utilization of local climate and site conditions, the emphasis on natural ventilation through design, fundamentally lessen operational costs and positively impact the environment.
[citation needed] Other materials are avoided by practitioners of this building approach, due to their major negative environmental or health impacts.
These include unsustainably harvested wood, toxic wood-preservatives, Portland cement-based mixes and derived products such as Autoclaved aerated concrete, paints and other coatings that off-gas volatile organic compounds (VOCs), steel, waste materials such as rubber tires in regions where they are recycled, and some plastics; particularly polyvinyl chloride (PVC or "vinyl") and those containing harmful plasticizers or hormone-mimicking formulations.
[citation needed] One of the oldest building methods, adobe is simply clay and sand mixed with water.
[4] To protect the walls and reduce maintenance, adobe buildings usually have large overhanging eaves and sizeable foundations.
The traditional thick, un-insulated adobe has proven to perform best in regions without harsh winters or where daily sun is predictably available during those cold periods.
[citation needed] The term cob is used to describe a monolithic building system based on a mixture of clay, sand, straw and earth.
Various forms of "mud" building have been used in many parts of the world for centuries, under a variety of names, and date from at least 10,000 years ago.
Cob building began use in England prior to the 13th century, and fell out of favor after World War I, although it is seeing a resurgence today.
Quality rammed earth walls are dense, solid, and stone-like with great environmental benefits and superior low maintenance characteristics.
Rammed earth has been used for around 10,000 years in all types of buildings from low rise to high-rise and from small huts to palaces.
Around 5-10 inches of mixed damp sub-soil are placed inside the forms and pounded to total compaction and the process is repeated until the desired height is achieved.
[8] The basic elements of timber-frame building—joined timbers, clay walls and thatch roofs were in place in Europe and Asia by the 9th century.
This building method utilizes stacked polypropylene or natural-fiber (burlap) bags filled with earth or other mixes without a stabilizer, other than clay, to form footings, foundations, walls and even vaulted or domed roofs.
Its growing popularity relates to its use of an abundant and readily available often site-available material (earth) in a potentially inexpensive building technique that is flexible, and easy to learn and use.
It is a low density material and resistant to crack under movement thus making it highly suitable for use in earthquake-prone areas.
Cordwood masonry construction provides a relatively high thermal mass, which helps to minimize fluctuations in temperature.
The pyramids in Giza, burial chambers in the UK and temples in Malta were all built from stone over 4000 years ago and are still standing.
These are freestanding structures such as field walls, bridges and buildings that use irregularly shaped stones carefully selected and placed so that they fit closely together without slipping.
