Principle: The residential site should maximize the reuse and recycling of ma­

terials that are on-site and in the surrounding region.

An integral part of sustainability is to produce the least impact on the environment through the wise use of materials. Reusing and recycling materials that are already on-site or in the nearby region can save raw material resources and the energy that is required to manufacture them. Embodied energy is the term used to describe the col­lective amount of energy it takes to obtain the resources for, manufacture, and trans­port a product to a site and is typically an invisible cost that can be surprisingly large. For example, the embodied energies for a few selected landscape materials are as follows.[19]

Подпись: Common brick Copper pipe Cut granite Earth External oil-based paint 3/4" ext. plywood Phosphatic fertilizer PVC plastic Sand Stone 1,075 to 4,085 ave. est. Btu/lb 73,100 2,537 172 42,962 4,472 32,373 35,130 16 446

Every attempt should be made to reduce the quantity of materials that have a rela­tively high amount of embodied energy or to substitute salvaged and recycled materials for them.

Transportation costs and air pollution are likewise minimized or eliminated when materials are reused and recycled. Materials that are given a second life do not add to the volume of already burgeoning landfills, either. In some instances, construc­tion costs are reduced as well when materials are reused and recycled. There are a number of ways of reusing and recycling materials on the residential site.