2.6b Renewable Materials

Feature	Materials that are renewable, meaning they can be grown and renewed over and over again, are valued by socially conscious buyers.  The tile seen here is made of cork, which is the bark of the cork oak tree.  Harvesting the cork does not harm the tree, and is ready for re-harvesting within 9 years. (Photo: Home Depot)
Function	Using renewable materials will contribute to what is known as “sustainability.” Using renewable materials can earn points in the LEED or NHAB green building rating systems.
	Types of Renewable Materials
Certified wood	There are several wood certification programs to ensure that wood is harvested from sustainably managed forests. The most prominent program is Forest Stewardship Council (FSC). Other programs include the Sustainable Forestry Initiative (SFI) and the American Tree Farm System (AFTS).
Engineered Wood	This is a product that is made up of wood products held together by binders. Rather than harvesting an old-growth tree to make large beams for a home, for instance, large beams can be made up of strands of smaller pieces of lumber, creating a very strong and sustainable product.
Bamboo	The uses for bamboo are growing quickly, as quickly as bamboo itself grows. According to the NAHB Research Council, bamboo grows into a merchandisable size in 3 to 5 years. You’ll find this product mainly in flooring, which is as strong and resilient as flooring made from wood. Not all bamboo is responsibly grown, however, so for the socially conscious buyer, certified bamboo will hold greater value.
Cotton	The most common use for cotton in homes is in cotton-based insulation.
Cork	According to the NAHB Research Center: Cork is actually the bark that is scraped off the Cork Oak tree, native to the Mediterranean basin.  The tree is not harmed by the removal of the outer layer of bark and the layer renews for harvesting every 9 years.  In addition, most of the cork that is used in flooring is the waste from the cork wine bottle stopper industry, so this fast growing material is also recycled from use by another industry when it goes into flooring. Cork’s specialized cell structure – honeycomb hexagonal cells comprised of 90% gas -  gives the material its lightweight and low density.  These properties make cork flooring soft and resilient underfoot and dampen sound while providing insulation.
Eucalyptus	Straw can be used for walls, as in straw-bale homes. But for the conventionally framed home, you may find straw-based cabinets.
Straw	According to the NAHB Research Center: Originally native to Australia, New Zealand, Tasmania, and nearby islands, eucalyptus is now being cultivated in South America as well as California. Globally over 500 species of eucalyptus exist. The tree can be harvested within 14 to 16 years due to the longer growing season of the climates where eucalyptus grows.
Soy	One common use of soy in home construction is soy-based insulation.
Resources	• LEED for Homes Materials and Resources point system