What it Means to Be Green
Materials must be evaluated for sustainability in light of their overall life cycle or entire history - from raw materials to manufacturing, transportation, assembly, and use to the ultimate disposal or reuse of the materials. The performance of a material in a building is just one stage in that cycle, albeit an important one. At the raw materials stage, concerns revolve around the impact of mining, harvesting, or extraction practices. The manufacturing stage involves the input of energy and the output of emissions or by-products. During the material's tenure in the building, it must be evaluated according to its durability, maintainability, contributions to air quality, and its effect on the cost or function of the structure. How the material is handled once it is removed from the building is something that should be determined when it is specified. It should be easily disassembled and either recyclable, salvageable, or biodegradable.
Using local materials reduces transportation costs, keeps money within the community, and contributes to a general awareness of the architectural qualities that make each region unique, which is an important component of ecological awareness. Also, local materials often jibe with the climate
Choosing the least toxic construction materials and furnishings is a way to address indoor-air-quality problems. Products that are applied wet have historically consisted largely of organic solvents that are released as volatile organic compounds (VOCs) as the products dry. As a result, many manufacturers have switched to water-based formulations, though these usually contain some VOCs. Most major paint companies now have products without any VOCs. Other less toxic solutions include alternatives to particleboard and MDF, which are almost always made with formaldehyde. Latex backing on carpets, a source of off-gassing, has been improved. Whether it's an individual product or a whole building, if it lasts longer, its environmental impact is amortized over a longer period of time.
Architects need to do extra work to make sure they get the sustainable materials they specify into the building. The environmental criteria must be prominent in the specs. Adding an "environmental requirements" article to each technical section makes these criteria more noticeable. Listing a contact name for any nonstandard products also helps, as does calling the supplier and informing them that their product is being specified. Be prepared to document the performance of unconventional materials. Having the other members of the team involved from the onset of the project creates a more holistic approach and means architects are less likely to have to defend their choices.