| "Introduction
All building materials are derived from natural resources. How we chose to use these resources has both direct and indirect effects on the environment. As specifiers of building materials, architects, engineers and designers should be aware of the impact of their choices. This paper outlines some of the factors to consider.
For many products and processes the major environmental impact arises from the consumed energy. More than 80 percent of North America's energy comes from fossil fuels. Fossil fuels are non-renewable and their use is linked to global warming, thinning of the ozone layer, and acid rain. We must reduce our consumption of fossil fuels to improve the quality of life and to sustain the environment. It is important to choose building materials that require less energy to produce and to use.
An extensive survey (Ref. 1) of North American architects and engineers found that 68 percent thought environmental considerations were important when specifying structural materials. The survey also found that, overall, wood was considered the most environmentally friendly building material (masonry ranked second, concrete third, and steel fourth).
Although the survey used scientific methods, it measured perceived environmental effects - not the actual effects. Perceptions can be influenced by factors such as media reports and advertising. Fortunately, public concern about the sustainable use of materials has prompted accelerated scientific research in this area. This paper uses recent scientific data to test the validity of the perceptions uncovered in the survey. ..." | 