What is Sustainable?

To me?

I am talking about the ways in which to live in and build with this world!

When talking about architecture, that means talking in terms of the materials it takes to construct a place. In the April 08 issue of Architectural Record I find great resources to cumulate together for my use as an architect and thought I would share:

The author, B.J. Novitski discusses the Life-Cycle Assessment – a methodology that quantifies the environmental impact of a material by examining how it is grown, harvested, transported, maintained, and eventually disposed of, computing costs in energy and water use, air degradation, and other factors…architect William McDonough and chemist Michael Braungart offer their Cradle to Cradle (C2C) material assessment, product development, and certification to manufacturers.

McDonough and Braungart argue that when a product is made of appropriate materials and is designed so that its constituent parts can be recovered at the end of its useful life, any waste is “food.” The waste becomes raw material for the manufacture of more products…

…some rapidly renewable materials more green than others. The circumstances of production may cast a shadow on the sustainability of an agricultural product: Are fossil fuels, irrigation, or harmful chemicals used in its cultivation or manufacturing? Is the crop diverting acreage from food production? Are natural forests being destroyed to produce raw materials for construction? Does transportation consume inordinate amounts of fossil fuel?

Brendan Owens, USGBC vice president of technical development…points out that the term “renewable” should be considered in context. “If you’re using wood for structural framing in a house that will exist for 100 years, ‘rapidly renewable’ might be 50 years, because the resource regenerates in less time than one cycle of its use.”

So, lets talk about materials!

  Cork is the bark of cork oaks grown in the Mediterranean region. Unlike nearly every other tree species, it is not harmed by removal of its bark. A mature tree is stripped about once every 10 years and lives for an average of 16 strippings. The cork oak forests thrive without chemical herbicides, fertilizers, or irrigation and provide habitat for wildlife such as the threatened Bonelli’s Eagle and Iberian lynx. After stripping, the large slabs of bark are boiled, and bottle stoppers are punched from them. The leftover material is then ground up, pressed into sheets, and cut into tiles for flooring.

  Cotton is now being used for building insulation.  Bonded Logic in Arizona produces r-30 batts from post-industrial recycled denim, the scraps from manufacturing blue jeans, diverting about 200 tons of material per month from landfills!

  Natural linoleum, such as Forbo, is formed from a variety of rapidly renewable materials, including linseed oil, wood flour, and pine rosin. During production, the ingredients are heated, mixed, and rolled flat. The sheets are cooled, backed with jute, then dried and trimmed. Pigments that do not contain heavy metals are used to achieve a wide variety of colors and unusual flooring installations.

  Agriboard Industries  in Kansas, produces a composite structural panel from highly compressed wheat and rice straw sandwiched between oriented strand board…The panels provide both structure and insulation in wood floors, walls, and roofs…The manufacturing process combines heat and pressure, drawing lignin from the cell walls of the straw, and creating a natural binder that obviates the need for urea-formaldehyde or other additives. 

Environ Biocomposites makes a particle board combining wheat straw and sunflower hulls with urethane-based resin instead of the urea-formaldehyde binders.

   In only five to six years, bamboo grows to a height of 40 feet and a diameter of 6 inches, and can be harvested without killing the root system, which then regenerates it. The hollow stalks are cut into strips which are dried, planed, and glued together to form durable flooring, plywood, and veneers. Some bamboo importers, such as EcoTimber and Smith & Fong, now offer products without urea-formaldehyde and are encouraging Chinese foresters to move away from use of pesticides, herbicides, and chemical fertilizers.

Bamboo is a case in point. This fast-growing grass is hard enough to be used as a replacement for wood in applications such as flooring and furniture. However, most bamboo is grown and processed in China, and there are concerns about forestry practices, the toxicity of binders, and worker safety. A few bamboo plantations have earned certification from the Forest Stewardship Council (FSC), which accredits forests managed “to meet the social, economic, ecological, cultural, and spiritual needs of present and future generations.” However, certified bamboo products are still not widely available in the U.S. And even though bamboo plantations sequester as much carbon as native forests, they do not support the same wildlife. What is more, while ocean shipping consumes less fuel per mile than overland trucking, the fuel used in shipping is more polluting. Clearly, the environmental balance is more difficult to calculate than by simply examining the length of a harvest cycle.

(all above descriptions of products taken from Architectural Record’s B.J. Novitski’s April 08 issue)

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