 The use of modified post-consumer or post-industrial recycled material in building supplies is important to reducing demand on natural resources. The recycling process is also less energy-intensive, resulting in lower consumption compared to the process of manufacturing new materials. Materials that are easily recycled include glass, metal, plastic, concrete, brick, and wood.
Recycled content is typically evaluated based on two metrics: the portion of recycled content in a finished product and the reclamation rate. While the percentage of recyled content provides important information about the amount of raw materials that were used in the manufacture of a product, the reclamation rate is a measure of how often the product or material is recycled at the end of its lifespan.
Many recycled buildings products are composites of two or more original materials. Examples include recycled deck lumber, often produced as a highly durable mixture of wood and plastic, recycled carpets which can be a mixture of original carpeting and plastic bottles, and recycled tile which is typically made of glass mixtures (1).
Recyled metals, particularly steel and copper, are usually in their pure form rather than a composite. Manufactured steel products are ideal for reprocessing as they tend to have both a good reclamation rate and high recycled content. According to the American Institute for Steel Construction, structural steel has a recycling rate of 98%, with mills commonly producing steel products containing 93% recycled content (2). Copper-containing building products also tend to have high recycled content (80%) and good recovery rate, with approximately 80% of all mined copper still in use today. Recycled copper is versatile, and is used in many applications including roofing, sun shades, eaves, downspouts, bathroom fixtures, electrical systems, and photovoltaic cells. It is also a durable material capable of lasting multiple generations (3).
Sources
1 Ecology Action, 2009. Green Building Materials Guide: Recycled Content Building Materials (webpage).
2 American Institute of Steel Construction, 2009. The Sustainable Aspects of Structural Steel (webpage).
3 The Copper Development Association, 2006. Building Green: How Copper can LEED the Way (webpage).
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