by kevin, on October 29th, 2009
part 2 of 5
The US home building boom that raged between 2004 and 2007 created construction shortages experienced throughout the country. Some regions – southern FL, Phoenix AZ, southern CA, and Las Vegas NV – saw extreme scarcity of vital materials. Hurricane Katrina rocked the system in 2005. Rebuilding projects in the gulf states added strain to already taxed supply. Concrete, gypsum wallboard, OSB, plywood, and other materials became extremely scarce. At the same time, China was adding pressure to the steel supply with their push to complete construction projects in time for the 2008 Olympic games and recovering from an earthquake in the Sichuan Province. Oil price increases during this period led to higher steel prices, more expensive transportation, and a fifty-two percent rise for framing lumber. According to the National Association of Home Builders, these and other shortages raised average home construction by $5,000 to $7,000 per home. Under normal circumstances, that kind of price increase could slow down growth. We now know that rampant housing speculation ensured demand outstripped supply, home prices rose at considerably higher rates, and climbing material prices were easily absorbed.
These shortages did little to halt the pace of construction, but did lead to consequences just now becoming apparent. To alleviate a dearth in gypsum wallboard supply, builders turned to alternative sources. It’s estimated that 100,000 homes in twenty states were built with toxic wallboard imported from China which must be replaced (I’ll cover this issue in a follow-up post). According to National Underwriter, an insurance industry publication, rectifying the situation could cost $15 to $25 billion – which includes material exchange, legal fees, and health impacts.
What will happen when natural resource supply cannot keep pace with demand? Or worse, when supply is dramatically reduced or extinguished? As mentioned in the previous blog post, if a resource becomes too scarce and expensive, incentive is created to seek abundant alternatives. But what happens when the alternatives are toxic, like the Chinese gypsum wallboard? What if the most abundant replacements are worse than the original material or product being substituted? These conditions may have been coincidence, once in a lifetime, and/or unlikely to repeat. But they demonstrate how sensitive and vulnerable the construction industry is to resource supply changes. Attempts to adapt were slow and, in some cases, dangerous.
In the US, natural resources have expired in the past. The American chestnut was at one time a very important timber species. It was a plentiful hardwood that grew faster than oak, was straight-grained, and highly resistant to decay. Early in the 1900s, the species was decimated when a fast-acting airborne bark fungus known as chestnut blight was accidentally introduced. Asian chestnut trees, which have evolved to be less susceptible to the blight, were imported to the Bronx Zoo carrying the fungus. Spreading at a rate of fifty miles each year, along with panic harvesting that may have accelerated the destruction, the blight wiped out a valuable timber product in fifty years. It’s estimated more than three billion trees were lost.
Today, no new American chestnut is available. There are less than one hundred adult trees remaining in its historical range, and another one thousand in parts of the country outside the historical range where the blight was less virulent. The wood was very versatile and often used to construct barns throughout Appalachia. Butternut, ash, and American elm are also at risk due to similar problems. Throughout the world, other timber species are endangered, threatened, or vulnerable, with names we’re probably all familiar with – African mahogany, teak, Brazilian cherry, wenge, redwood, western red cedar, cherry, and many more. There are dozens more not typically used in US building construction. I list all these examples to show how quickly natural events can occur to wipe out valuable resources. One hundred years later, the US population is three times what it was. Significantly greater demand on wood products combined with a natural calamity and far more aggressive harvesting practices means the US timber industry is at greater risk of rapid collapse.
Large scale drastic and permanent resource shortage is unlikely to occur in our lifetimes, but that’s no reason to discount preservation strategies which prolong access to and ensure stable supply of natural capital. Sustainable age design must consider two components when addressing resource preservation – extraction and waste. I’ll deal with waste issues in a later post. Extraction, as the word implies, is the removal of raw material from the environment and conversion into useful human purpose. There are two resource classifications for those extracted – renewable and non-renewable. Renewable resources are those where supply is continually replenished through natural processes – such as wood, water, and other plant life. Non-renewable resources have limited supply, were created through massive ancient geological processes, and no new supply is being generated – such as steel, oil, and stone.
Carefully determining material selection criterion and defining your own vetting process are two critical steps in crafting a resource preservation strategy. At thread collaborative we’ve spent the last six years honing our specification system and we’re pretty confident it helps us make intelligent sustainable material selections. We categorize sustainable building products in six groups – those that can be reused with minimal refurbishing, those that have been reclaimed and repurposed, those with a high percentage of recycled content, those made with rapidly renewable resources, those that reduce virgin source depletion, and those that rethink existing products or employ new technologies.
These six (reused, reclaimed, recycled, rapidly renewable, reduced, and rethought) have become our organizing structure for a sustainable materials database we’re building, for our material specification coding and notation system, and for our material sample library. Others who have offered similar groupings insist that they be accompanied with a selection hierarchy, suggesting that certain strategies should take precedence over others. In my experience, every project and every client is different. And every design solution requires a unique methodology and approach to materials. Therefore, the order of our list is not a suggestion of preference or ranking. Instead, the first three are loosely related to each other as options for returning previously produced components and materials back into the construction and/or material production cycle. The second three are loosely related to each other as raw materials.
I will dive into each of those six categories in detail in my next post. Please come back to check it out.
This is part two of five about resource preservation. Part one is entitled resource preservation – context, part three is entitled resource preservation – strategy, part four is entitled resource preservation – sources, and part five is entitled resource preservation – design.
[...] resource preservation – criterion [...]
[...] resource preservation – criterion [...]
[...] resource preservation – criterion [...]
[...] resource preservation – criterion [...]