Sustainability will only come when we learn to reduce waste to near zero.
In nature there is literally zero waste-- everything that dies becomes part of something else-- food for some other process. In the built environment there is well over 90% waste. Over 65% of energy produced is wasted.
By reducing the energy load (how much energy the building requires to meet the inhabitants needs) and minimizing the amount of non-renewable material in the building and the imbodied energy it took to manufacture and get the materials to the site, we learn to approach true sustainability.
In other words, a sustainable house would be one which is built and maintained in such a way as could be done indefinately without ever causing a situation in which future generations would not be able to build the same house for the same amopunt of money (adjusted).
The passive Solar House below was designed to include approximately 3000 SF of heated space with half the volume of materials that might be in a conventional Home. of the same area.
