The Costs of Production

Historically, operating costs have always been among the primary concerns of any business. These costs are normally calculated with little difficulty. Today many businesses are also concerned about the environmental costs of the raw and manufactured materials they consume in an effort to have the least possible detrimental effect on our shared Earth. But what should be included when calculating environmental costs? Do we include items such as terrestrial alterations, waste by-products, air and water emissions, fuel consumption, etc.? Surely, in order to provide a compete comparison of environmental costs, we must consider all possible inputs.

Some of the environmental costs of a product or raw material are very difficult to quantify in terms of a dollar value. What are the social costs of strip-mining a forested area and someday turning the exhausted site into a lake or simply leaving it barren? What is the dollar value in human impact of cutting timber in forested areas and replacing the removed trees with saplings? How de we arrive at a dollar value for creating landfills in our environment to hold spent products and materials? How much does it cost to cover an acre of land with mine tailings? Does the extraction of non-renewable resources carry a heavier environmental cost that of renewable resources? Clearly, there are many areas that are subject to debate when calculating environmental costs.

Comparing the Costs of Energy Consumption

Perhaps the best way to calculate the environmental costs of producing a given product or material is to quantify the units of energy used its production. Since almost all of the power required for the extraction and production of most products and raw materials is generated through fossil fuel consumption, we may assume that as the units of energy required for production increase, so too do the environmental costs. Hydro-electric dams change ecosystems and biodiversity. Burning fossil fuels emits contaminants to air, water and land. Scientists agree that the burning of fossil fuels contributes greatly to greenhouse gasses and the global warming that we hear so much about these days.

The energy inputs required for producing wood, steel, concrete and plastic or fibreglass composite materials have been reliably calculated by many sources. In a report by the Committee on Renewable Resources for Industrial Materials (CORRIM), the values for the total energy needed to extract, manufacture and transport wood products were calculated along with those for aluminum and concrete. In their findings, the total energy units required for extracting, manufacturing, delivery and erecting the structural components of a 100-square foot wall were:

• 2x4 lumber frame with plywood siding, no sheathing (untreated) - 2,100 MJ
• 2x4 lumber frame with plywood siding, no sheathing (CCA treated) - 2,540 MJ**
• aluminum siding over sheathing - 5,222 MJ
• concrete block, no insulation - 17, 437 MJ

** Additional energy inputs for treatment in CCA from Stalker, Conklin, 1996.

In their paper given at the 96th annual meeting of the American Wood-Preservers' Association, Stalker and Conklin studied the energy requirements for utility poles produced from wood treated with CCA, steel and concrete. A class 4, 40-foot Southern Yellow Pine pole was used as the basis for comparison in their evaluation. Their findings for the energy required to produce a comparable utility pole in each of the materials from raw materials extraction to delivery of the finished products are summarized in the table show here:

A study conducted by the Canadian Wood Council comparing the costs of a wood stud wall to a steel stud wall also found similar, drastic savings in the wood stud wall.

Wood Wins!

Man's demand for construction materials will continue. Our challenge is to select and use those materials which carry the lowest environmental price tag.

While it must be stressed that these findings deal only with costs up to and including erection of the final product, and a complete environmental life-cycle would require more data, two things are clear: CCA treated wood requires less energy to manufacture than alternative materials and therefore has less negative environment impacts associated with producing the energy consumed in its production.