People make the buildings—the materials are only a part. A building is a manifestation of human ingenuity and relationships. It takes the right people to make a building that approaches sustainability, and finding them is equally important to material choices.
Example: Straw-bale walls built poorly by an inexperienced builder can have greater compromised energy efficiency than well-built stud-framed and conventionally insulated walls.
If a product claim sounds too good to be true, it probably is. There is no perfect building material. If a material scores lots of “green” points in one or two areas, it probably has drawbacks in others. Find out both the pluses and minuses before making a decision.
Find trustworthy sources to help your decisions. Third-party certification (especially those overseen by boards that aren’t dominated by industry representatives) is a good way to ascertain a product’s environmental claims.
Beautiful buildings tend to receive care and maintenance, and last a long time. If nobody cares about a building, even if it scores lots of sustainable points for its material selection, it is more likely to have a short lifespan. Create something that future generations will appreciate, and they will shepherd it through time.
Greenwashing—where environmentally harmful products and materials are marketed as being green—is a large barrier to reducing our impact. Without considering the entire life cycle of the elements in our buildings, we cannot know if we are minimizing our impacts.
Homeowners or builders must first establish their environmental goals, and then consider materials that perform well without undermining overall environmental performance. Environmental merit can be judged in three categories:
Low overall energy consumption in the finished building. This may be the most comprehensive way to judge the “greenness” of a material or system. Energy Star, EnerGuide, and a host of energy modeling software programs can be used to compare energy impacts of materials and systems.
Reduced toxics or environmental impacts. Using recycled material, reducing embodied energy, responsibly harvesting and producing, durability, and reducing or eliminating waste are all included in this metric. The Inventory of Carbon & Energy (download at bit.ly/ICEdwnld) is a free database for comparing embodied energy of materials. Free software programs like the Athena Institute’s Life Cycle Assessment (athenasmi.org) can help with understanding environmental impacts over a material’s life span.
Creation of a nontoxic interior environment. Clean air and water; proper humidity and ventilation; access to natural light; comfortable interior temperatures; and reducing or eliminating radon are included. Greenguard (greenguard.org) is a reliable third-party rating system for a product’s impact on indoor air quality; the Pharos Project database (pharosproject.net) has in-depth information on chemicals in building materials.
These three areas constitute a building’s life-cycle analysis. Ideally, for each product, materials research follows the path of all materials and systems—from harvesting raw ingredients to manufacture, transport, and use, to waste and disposal issues.