Green Building Materials
The concept of sustainable building incorporates and integrates a variety of strategies during the design, construction and operation of building projects. The use of green building materials and products represents one important strategy in the design of a building.
Green building materials offer specific benefits to the building owner and building occupants:
Building and construction activities worldwide consume 3 billion tons of raw materials each year or 40% of total global use (Roodman and Lenssen, 1995). Using green building materials and products promotes conservation of dwindling nonrenewable resources internationally. In addition, integrating green building materials into building projects can help reduce the environmental impacts associated with the extraction, transport, processing, fabrication, installation, reuse, recycling, and disposal of these building industry source materials.
Green building materials are composed of renewable, rather than nonrenewable resources. Green materials are environmentally responsible because impacts are considered over the life of the product (Spiegel and Meadows, 1999). Depending upon project-specific goals, an assessment of green materials may involve an evaluation of one or more of the criteria listed below.
Green building material/product selection criteria
This information was based on Lynn Froeschle's article, "Environmental Assessment and Specification of Green Building Materials" (Adobe PDF, 1.4 MB), in the October 1999 issue of The Construction Specifier, a publication for members of the Construction Specifications Institute (CSI). Selection criteria similar to what is presented below was also used for the East End Project as identified in the Review of Construction Projects Using Sustainable Materials.
Overall material/product selection criteria:
Resource Efficiency can be accomplished by utilizing materials that meet the following criteria:
Indoor Air Quality (IAQ) is enhanced by utilizing materials that meet the following criteria:
Materials, components, and systems that help reduce energy consumption in buildings and facilities.Energy Efficiency can be maximized by utilizing materials and systems that meet the following criteria:Water Conservation can be obtained by utilizing materials and systems that meet the following criteria:
Affordability can be considered when building product life-cycle costs are comparable to conventional materials or as a whole, are within a project-defined percentage of the overall budget.
Three basic steps of product selection
Product selection can begin after the establishment of project-specific environmental goals. The environmental assessment process for building products involves three basic steps.
Research This step involves gathering all technical information to be evaluated, including manufacturers' information such as Material Safety Data Sheets (MSDS), Indoor Air Quality (IAQ) test data, product warranties, source material characteristics, recycled content data, environmental statements, and durability information. In addition, this step may involve researching other environmental issues, building codes, government regulations, building industry articles, model green building product specifications, and other sources of product data. Research helps identify the full range of the project’s building material options.
EvaluationThis step involves confirmation of the technical information, as well as filling in information gaps. For example, the evaluator may request product certifications from manufacturers to help sort out possible exaggerated environmental product claims. Evaluation and assessment is relatively simple when comparing similar types of building materials using the environmental criteria, e.g., a recycled content assessment between various manufacturers of medium density fiberboard is a relatively straightforward "apples to apples" comparison. However, the evaluation process is more complex when comparing different products with the same function. Then it may become necessary to process both descriptive and quantitative forms of data.
A life cycle assessment (LCA) is an evaluation of the relative "greenness" of building materials and products. LCA addresses the impacts of a product through all of its life stages. Although rather simple in principle, this approach has been difficult and expensive in actual practice (although that appears to be changing).
One tool that uses the LCA methodology is BEES (Building for Environmental and Economic Sustainability) software. It allows users to balance the environmental and economic performance of building products. The software was developed by the National Institute of Standards and Technology's Building and Fire Research Laboratory and can be downloaded free on their Web site.
Selection This step often involves the use of an evaluation matrix for scoring the project-specific environmental criteria. The total score of each product evaluation will indicate the product with the highest environmental attributes. Individual criteria included in the rating system can be weighted to accommodate project-specific goals and objectives.