Building+materials

Traditionally designers have focused on physical properties when choosing materials, such as strength, flexibility, durability, or whether a material conducts electricity or repels water, depending upon how the material would be used. Other important considerations are the cost and availability of materials. In the last few decades a new concern has arisen - the effect of materials on the environment. The extraction, manufacturing, use, and disposal of materials may include significant environmental impacts that have to be remediated. Some materials, once heralded for their benefits to mankind, have later been found to have had unexpected consequences. Chlorofluorocarbons (CFCs), for example, were developed in the early 1930s and used for a variety of purposes, including as a coolant. The development of air conditioning and refrigeration has had many far-reaching impacts beyond providing comfortable environments. Cooling systems made it possible to keep food without spoiling, to ship vaccines and other medicines around the world, and to manufacture products that require clean, cold environments, such as silicon chips, among other things. Yet CFCs were found to have an unanticipated role in the upper atmosphere, leading to depletion of the ozone layer. In a treaty signed in 1987, most nations agreed to phase out the use of CFCs. A primary consideration in materials research today is the minimization of environmental impacts. New materials have been developed, such as biodegradable plastics that are more environmentally benign than those they replace. A new field of research, industrial ecology, seeks to minimize waste and environmental impacts by mimicking natural processes in which one organism's waste is another organism's food. The goals of industrial ecology are to reduce the flow of matter and energy embedded in products, to use less toxic materials, to reduce the amount of waste byproducts in the manufacturing process, and to design products so that they can be easily disassembled and recycled. []

Sustainable materials Eco hierarchy - decision tree for building material choice

Local production

The workshop

Material properties

Wood Clay or earth Fibre Glass Concrete Asphalt or tar
 * Poles
 * Wool/fur
 * Cotton
 * Flax (linum)
 * Harekeke
 * Paper
 * Straw or chaff

Tyres

Synthetic materials - Green chemistry Plastics Bioplastic

Steel or other metal

Finishes Maintenance

Renovation or reuse

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Eco building materials have very minimal impact on the environment or helps in conserving energy. These materials come from renewable resources and are non-toxic. They are durable and need minimal maintenance. It can be cleaned easily without the use of chemical detergents. Such materials reduce toxic emissions and helps in providing a toxic free environment for its inhabitants. Cellulose insulation has low organic compound-emitting materials which can be used for insulation. Building materials are made from plant materials, sustainable lumber, recycled stone, non-toxic, renewable and recyclable products. Green homes make efficient use of sunlight and wind and make great energy savers. An enormous volume of gas emission can be reduced by simply constructing buildings that use energy efficient concepts.

** Sustainable Insulation **Sustainable Insulation Good insulation conserves significant amount of energy. Insulation made from recycled materials do not contain chemical irritants. A properly insulated building brings down energy emissions as well as electricity bills. There are many green and sustainable alternatives that can be used for insulation. ** Best types of green insulation **
 * 1) Sheep Wool Insulation : This is an excellent insulation material and has low embodied energy. It needs to be treated with chemicals to reduce fire risk and prevent mite infestation. These are natural, non-flammable and make it very eco-friendly.
 * 2) Cellulose: This is made of newsprit and other cellulose fibre. It can be used in floors, roofs, used as loose fill or in quilts, batts and boards.
 * 3) Flax and Hemp : These are made of natural plant fibers and have low embodied energy. This can be used as a fire retardant, fungicide or an insecticide. Few examples are Flax 100 and Isonat.
 * 4) Eco Fiberglass – This environment friendly product contains forty five percent of recycle materials. It uses binders that have zero formaldehyde.
 * 5) Expanded Clay Aggregate : These small clay pellets can be used as an aggregate and insulator. It expands at high temperature and become weight-bearing and have good insulation properties.