All of the refuse that results from the demolition of a house (or any other structure) falls into the category of construction and demolition waste. This waste stream is a wide and deep one in the United States. On average, it adds up to about 136 million tons of waste annually -- or a whopping 40 percent of the solid waste dropped off at municipal dumps every year [source: EPA].
Gutting a house entirely and saving only the exterior and internal load-bearing walls helps cut down on the waste generated by remodeling the home. If you compare the amount of trash generated by each process, renovating is greener than rebuilding. Again, however, the devil is in the details when it comes to determining what's green. Think of it this way: A homeowner who puts notices on sites like Freecycle.org or Craigslist.org to offer salvage materials will seem greener than someone who renovates and sends all debris straight to the dump to rot.
Renovation still tends to be greener than rebuilding, especially for waste reduction purposes. This is especially the case with small startup green demolition companies, like the Seattle-based nonprofit RE Store. The group salvages and sells as much of a house undergoing demolition as possible and recycles whatever remains -- down to the nails. In 2007, four of the company's projects received recycle or reuse ratings of between 70 and 97 percent from the Environmental Protection Agency [source: Stiffler].
It takes considerably longer to deconstruct a house by hand than it does to bulldoze it, but the green approach to demolition is catching on. Even if a home is demolished in an eco-friendly manner, keeping an existing structure standing will require less heavy machinery when the home is rebuilt. This means that the land surrounding the house will remain undisturbed, leaving trees and other greenery intact.