And as though the figures for materials weren't confusing enough, calculations of embodied energy will be different for each job site. Factors such as distance of the site from manufacturer, distance from railhead, and even the distance that tradespeople must travel to and from the site during construction, are all part of the embodied energy equation. Furthermore, the type of fuel used in processing and transporting materials can affect the amount of embodied energy contained in the final product. Two products of identical appearance may have different embodied energies, depending on where and how they were made, and where and how they will finally be used. Given these complexities, builders bent on reducing energy consumption should learn as much as possible about materials options, and consider the probable relative embodied energies of these materials.
Recycling provides easily obtainable manufacturing feedstock.
There is very low extraction energy associated with recycled materials. While these figures will vary with the quality and quantity of recycled feedstock, as well as with the efficiency of the processing equipment used, they show that using recycled materials as raw material for manufacturing can result in substantial energy savings for at least a few frequently used materials. Reusing materials , or even reusing entire buildings by retrofitting them, reduces the total amount of embodied energy even more than using recycled materials. Although reusing materials often requires intensive cleaning, and frequently entails repair, it represents a means of attaining substantial embodied energy savings. Builders can save embodied energy by incorporating as many salvaged and reused building components as practical.