When savvy Silicon Valley venture capitalists begin referring to the selling, renting, and swapping of products and services via social media networks as "underworked asset utilization," you know that a serious business category is emerging.

Initially, social media was considered by most of us as simply a fun way to share personal information and expand business networks. But recently, we've witnessed the evolution of social networks as they catalyzed radical change in the Middle East and helped to save lives after natural disasters in Japan and the American Southeast.

Nourished by a perfect mélange of financial crises and environmental tragedy, social networks have not only transformed the way we share information, but they have also redefined commerce. They have given birth to a new, virtual "sharing economy," in which participants use social media to sell, rent, or swap everything from cars to baby clothes to remodeling services.

Expected to grow to approximately $26 billion by 2016, the sharing economy will inexorably affect the building industry in two primary ways.

First, since the sharing economy enables direct interaction between individuals (buyers and sellers) through free social media channels, the corporate middleman is potentially eliminated from the sales equation. Forward-thinking manufacturers, not wanting to be separated from revenue streams, will develop "product for service" offerings, where the manufacturer rents products to an individual for a period of time, takes the product back at the end of its life cycle, and reuses the parts for the next generation of products (think Hewlett Packard or Ricoh).

Second, since peer-to-peer sharing—the basis of the sharing economy—occurs on a local or community scale, entrepreneurial building professionals will figure out how to optimize the use of social networks to market their companies and promote their services.

There was a time when a strong handshake and a smile were all that was necessary to close a deal. But technology has indelibly transformed our culture and our business climate. By prioritizing access to goods over ownership of them, the sharing economy has the potential to revolutionize the very way we perceive, purchase, dispose of, and interact with products.

Sound farfetched? Harbingers of change are already here. The company that started the car-sharing phenomenon, Zipcar, is going public (even though it has never turned a profit and its leadership position is being challenged by startups with stronger business models). And large corporations like Peugeot and Daimler have jumped into the car-sharing sector by launching mobility rental services that are expected to usher in a new era of automobile manufacturing.

Even big boxes like Lowe's are beginning to take the sharing economy seriously, refining their business models to incorporate greater levels of services (like product rentals) as people continue to purchase fewer new products and downsize.

While it is unlikely that this new fold in the fabric of commerce will affect the basic desire to own a home, it's inevitable that the sharing economy will affect the process by which a home is built, the services that are rendered during that process, and the products that go into that home.

Want to learn more about the sharing economy? Visit www.greenbuildermag.com, like us on Facebook, and follow us on Twitter @greenbuildermag for regular updates and breaking news. Have information about the sharing economy? Write to me at sara@greenbuildermag.com or follow me on Twitter @SaraGBM.

I saw a sweet story on the news last night that caught my attention. It was about a pear tree that stood for years adjacent to the Twin Towers in New York City.

On that dreadful 9/11 day, along with all of its surroundings, the tree was blasted to pieces. But the tree's trunk and roots remained intact, so caring individuals transported the tree to a nearby nursery, where it was revived to health.

The "survivor tree" weathered the torment of the elements for almost a decade, and was recently replanted at the Twin Towers memorial site. While clearly not comparable to the major victory that the war on terrorism celebrated this week with the death of Osama Bin Laden, the replanting of the little pear tree is a small triumph nonetheless.

To me, the tree is the very embodiment of the spirit of unity that emerges amongst individuals and nations in times of great joy or sorrow. Recent history seems to be testing the fortitude of that spirit of unity through a violent barrage of repeated and inescapable natural disasters.

Within the last week alone, tornadoes in the southeast have left hundreds dead and thousands homeless, and the rising of the mighty Mississippi river involved the Supreme Court in an excruciating decision to blow up levees from Illinois to Kentucky in an effort to temper the bloated waterway while saving as many lives as possible.

The silver lining of disasters is that they offer us the chance to transform ourselves into heroes. They fuse individuals and communities together to extract catharsis from grief. They provide us with the opportunity to rebuild our lives and our world. And in that recovery is the hope of a new and better life.

The citizens of Greensburg, Kan., held tightly to that hope of a better life in May 2007 after an EF5 tornado leveled their rural town, when they made the decision to rebuild the town sustainably. With the guidance of visionary Daniel Wallach and his not-for-profit Greensburg Greentown, the community realized that building green was the only way to turn their dying community (which was previously dependent on agriculture) into a thriving model for green building and sustainable living. Greensburg's guidelines for rebuilding rural and urban communities sustainably after a disaster can be used across the country to help expedite the journey down the long, agonizing road to recovery.

As the climate changes and weather becomes more extreme, tornadoes, hurricanes, fire, drought, and other natural disasters will continue to plague communities around world. The choices we make today about how we rebuild our communities will significantly affect our quality of life on this planet.

Do we have the courage to move beyond what has been to what can be? Are we too much like Narcissus-so in love with the status quo that we miss the opportunity to evolve beyond it? Or can we be like the little pear tree, bravely enduring the storm and reincarnating ourselves season after season?

Have ideas about how we can rebuild sustainably after disaster? Write to me at sara@greenbuildermag.com or follow me on Twitter @SaraGBM.

You can also find Green Builder Media on .