One of the biggest impacts a home has on the overall world environment is also one of the least visible. The miles of copper wiring, plumbing and piping hidden behind the walls of almost every house in the first world result in devastation that most of us never even hear about.

Although the US is one of the world's biggest copper miners, it's also the biggest user and imports hundreds of thousands of tons of metal from less-developed countries. In those countries where laws are less stringent, the environment is severely damaged by the production of tailings and other pollution, whole communities are displaced and pristine green areas are contaminated or destroyed.

Unfortunately, copper is still used by default in almost all construction, despite the availability of alternatives. For piping, the obvious choice is to use recycled copper but there are also non-metal alternatives such as PEX, PVC and CPVC.

For cabling, Category 5e (CATSe), Category 6 (CAT6) and fiber cables all reduce the amount of copper. Advances in wireless technologies also help reduce copper use, not only because there's less wiring but because systems such as Zigbee, WiFi, WiGig and Wireless HD all include attempts at reducing raw material use.