The design process must consider all variables:
1) Human Labor
2) Energy Use
3) Water Use
4) Material Use
5) Tangible Value
6) Intangible Value
7) Mechanical Effort
8) Use of Land, Water, and Air Space
9) Use of Time
10) Economics

The design process always considers the best method approach. In other words, it must ask whether or not a more suitable alternative is better and will it use less resources, even if it means overturning conventional wisdom. The design process will ask the same as the philosopher may ask, "How much material do we need to be happy? How many plastic bottles, tons of steel, or aluminum cans does it take to produce happiness? How much does humanity really need to be comfortable and happy? "

In summary, the design process measures all ecological impact of every operation by the same criteria. The basic principles are:
1) Reduce overall consumption.
2) Reuse resources.
3) Recycle resources.
4) Return resources to nature by biodegradable means.
5) Restore ecosystems affected by degradation.
6) Reclaim resources that have been improperly disposed.
7) Remanufacture and repair products.
8) Reform operations to conform to sustainable practices.