Question: What are rapidly renewable materials?
Answer: Rapidly renewable materials are natural, non-petroleum-based building materials (petroleum based materials are non-renewable) that have harvest cycles under 10 years.
LEED 2009 used rapidly renewable materials as a way to earn points in LEED. In LEED v4 these are referred to as “biobased materials”.
LEED v4 changed from rapidly renewable materials to biobased materials to provide accurate biobased/biogenic carbon content results to materials whose carbon source was directly in equilibrium with CO2 in the atmosphere at the time of cessation of respiration or metabolism, such as the harvesting of a crop or grass living its natural life in a field.
Examples of Rapidly Renewable Materials:
Such materials include bamboo, straw, cork, natural linoleum products (such as Marmoleum), wool, wheatboard, strawboard, etc.
In the LEED 2009 green building rating system, LEED MR Credit 6.0 states that rapidly renewable materials must be equal to no less than 2.5% of the cost of a building project in terms of value.
Additional LEED MR Credits may be earned for using specific percentages of recycled content, regional materials or a combination.
Some green building materials products are comprised of a composite of rapidly renewable materials and recycled content such as newsprint, cotton, soy-based materials, seed husks, etc. Environ Biocomposites creates a line of rapidly renewable composite materials for various LEED Materials and Resources credits including: MR Credit 4.1, MR Credit 4.2, MR Credit 5.1, MR Credit 5.2 and MR Credit 6.0.
According to the LEED v4 BD+C Reference Guide, biobased products are defined by ASTM D6866, but testing (by the manufacturer or a contracted party) is not required in all cases. Manufacturers use this test to determine the amount of biobased material in a product. If the percentage of biobased materials, by weight, in the product are known, testing to this standard may not be necessary.