Charles Eley's Website

The Design Professionals Guide to Zero Net Energy Buidlings will be published in November by Island Press. I lay out the principles for achieving ZNE buildings and the issues surrounding their development.

In a previous blog, I used a lake surrounded by houses to illustrate the Tragedy of the Commons, a situation where the actions of individuals, motivated by their own self-interest, results in the destruction or damage of common assets, much to the detriment of the collective group. The pollutant used in the example was sewage, which is bio-degradable. As long as the emission rate is less than the lake’s ability to absorb or process the pollutant, it does not cause permanent damage to the environment.

Imagine a large lake surrounded by hundreds of private homes.  If just one of the houses dumped its raw sewage into the lake, the capacity of the lake could probably absorb the affluent with no serious damage, although floating debris could be annoying. After all, it is a large lake and we are talking about the waste from just one family. How could this possibly be a problem? Well, maybe the lake has the capacity to absorb the affluent from one family, but what about all the houses around the lake?