HousingZone.com articleFileName

Building Green in a Black and White World--Chapter 2

The following is an exerpt from the book Building Green in a Black and White World.
Section 1; Chapter 2; Part 2; Environmental Issues That Create the Market for Green Buildings-- Resource Conservation

David Ritchey Johnston
January 1, 1900
HousingZone

-------Resource Conservation--------




	Old-growth forest: A forest in which at least some trees are more than 200 years old

A variety of market forces have affected the construction industry and resulted in an increased interest in green building alternatives. One such force is the depletion of natural resources, which has given rise to resource-efficient building. In addition to consuming large amounts of energy, commercial and residential buildings account for roughly 40 percent of the materials entering the global economy each year.⁷ Approximately three billion tons of raw materials are turned into foundations, walls, pipes, and panels. Quarrying earth and rock to create bricks, gravel, sand, and blocks leaves large scars in the landscape. Other building materials such as aluminum, steel, and plastic require even heavier processing.

Wood Use

According to the World Resources Institute, America has harvested over 95 percent of its old-growth forests,⁸ which has increased the pressure on the forest products industry to develop substitutes for conventional lumber. The building industry accounts for almost half of the world’s demand for wood. Of that, one-third goes into lumber, plywood, particleboard, and other structural building material.⁹

Worldwide consumption of industrial timber (approximately 1.66 billion tons per year) exceeds the use of steel and plastics combined.¹⁰ The results of this high rate of timber consumption are the loss of the world’s forests at a rate of 37 million acres a year (approximately half the land area of Finland). The average house requires harvesting an acre of trees.¹¹

Our forests are not just declining in area, but also in quality. Twenty years ago, the average old-growth tree harvested from national forests was 24" in diameter. Today the average is 13". This shows up on the job site as lower quality lumber with more knots, unusable twisted boards, and boards that warp once they are in place.

Engineered Lumber and Recycled Materials

Engineered lumber products are an innovative alternative to solid-sawn lumber materials. Forest products companies have developed engineered lumber products to utilize fast-growing farm trees. These products are stronger, straighter, and lighter, and may use only 50 percent of the wood fiber to perform the same structural functions as solid-sawn lumber. Fast-growing tree farms, where forest product companies are planting more trees today than they harvest, are an example of a sustainable resource.

Strategic use of recycled content building materials has grown out of the increasing stockpiles of recycled material. Americans are recycling seven times more than they did a decade ago. Building materials are a perfect application for recycled refuse. Not only does recycling divert waste from landfills, but many of the remanufactured materials are of higher quality and durability than conventional materials. We can easily incorporate many resource-efficient materials, reclaimed wood, and recycled-content products such as carpet, decking, cellulose, and fiberglass insulation into homes cost-effectively.

Continue to Water Use