Discovery Guides Areas


Green Buildings: Conserving the Human Habitat
(Released October 2006)

  by Ethan Goffman  


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You Are What You're Made of: Green Materials


Beyond the stereotype that natural is good and artificial bad, the materials used in green should, ideally, be locally produced; be renewable, reused, or recycled; be conducive to human health; and, where applicable, have lower energy use. Perhaps the best strategy of all is, as environmental consultant Michael Braungart explains, "simply using less material to make things. Dematerialization, as this strategy is often called, is the materialists way to efficiency."39

green apartment perched on warehouse
A parasite grows in Amsterdam

Of the "reuse, reduce, recycle" trio, reusing is often overlooked, yet it has great potential. Materials found in local dumps are a cheap, easily available resource. Even the structure of old buildings may be creatively reused, as with the Dutch P.A.R.I.S.I.T.E.s that perch merrily upon the facades of old warehouses.40

In selecting materials that go into a building, a full life-cycle assessment is important regarding the overall, long-term environmental costs. According to the "Building for Environmental and Economic Sustainability" (BEES) standard, "all stages in the life of a product are analyzed: raw material acquisition, manufacture, transportation, installation, use, and recycling and waste management."41

How were the materials produced? Mountain top removal mining, for instance, is an environmentally disastrous way to produce materials, as is clear cutting of forests. Farmed materials can be far better, for instance in the production of wood. Care must be taken, however, that these are not produced using destructive techniques that lead to erosion, or with excessive pesticide use.

particleboard colorful countertop
The cash is always greener: formaldehyde free particleboard made from recycled money recycled glass countertop

Next in the life cycle assessment is transportation, which, over long distances, requires burning of fossil fuels. Locally produced materials are therefore best. Building techniques are also important; prefabricated units are often more environmentally friendly than building on site. Durability is critical; how long will the structure be in place before it needs to be replaced? What will happen to the materials once the building is no longer operating? According to The Construction Specifier, "construction debris account[s] for nearly 28 percent of landfill waste in this country,"42 and short-term, throwaway buildings make this problem even worse.

A question for late in the life cycle is whether a building's materials are easily recyclable or biodegradable. William McDonough talks about cradle to cradle materials use: "Wouldn't it be marvelous if instead of buying or burning all of the materials that we move through our system for our enjoyment, that we think of them as nutrition for other systems, and that they continuously cycle and reincarnate."43 With cradle to cradle principles, the death of one building means the life of a new one in an endless cycle of reuse that mimics-or conjoins-the processes of nature. Alternatively, if a material ends up as refuse, it's best that it contain no toxins that harm humans and the environment and that it degrade quickly.

Bamboo is, in many ways, an ideal green material since it is hardy, tough, and renewable. A grass rather than a tree, bamboo is renewable at a far faster rate than are hardwoods. Yet care must be taken; the environmental friendliness varies greatly according to the type of bamboo and the way it is grown. Furthermore bamboo is most often grown in China, which means a long supply chain, thus contradicting the above advice to use local products when possible. In other words, building green is tricky; the more knowledge the better, yet it is difficult to avoid some difficult trade-offs. As one source explains, "Very often, we are comparing apples to oranges. We are trying to weigh, for example, the resource-extraction impacts of one product with the manufacturing impacts of another, and the indoor-air-quality impacts of a third."44

green wall
The greenest of materials: A living wall of plants cleanses the air in this Canadian building
Still, as research, knowledge, and availability improve, expense of green materials is certain to go down. According to Braungart, "as an emerging market for recycled glass, sheetrock, carpeting, and reusable high-quality construction materials grows more stable, buildings and materials with many lives may become more the rule than the exception."45

A building has an impact not only on its environment but also on its occupants. Sometimes, but not always, a product or design choice can be good for both at once. With Americans spending some 90% of their time indoors, material should be selected to provide healthy indoor air quality. If you are what you breathe, many of us breathe in a mix of chemicals unique in the history of the human species, with "some new building chemical concentrations up to 100 times greater than outside levels."46 Many carpets, paints, sealers, and adhesives, for instance, give off volatile organic compounds (VOC) and other off gasses that can exacerbate health problems such as allergies and asthma. Careful attention must be paid to the health effects of different materials before beginning building.

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