Understanding transportation energy and technical metabolism of construction waste recycling

Energy and resource efficiencies are both critical to achieve building design and construction sustainability. Embodied energy is a measure of the energy required to produce, install, and maintain materials, while technical metabolism enhances building design recyclability. Nearly all types of materials can be recycled. However, the technical metabolism of the materials depends on the existence of a market for these recycled materials, the regional recycling capacities, the total energy used to recycle, and the knowledge of the workers and designers about material recycling on a construction project. Although the concepts of embodied energy and technical metabolism have been around for many years, the concepts have not been extensively applied to construction projects. This research examines the transportation energy use for recycling construction wastes and the actual rate of recycling of these projects. The study concluded that the recyclability of construction wastes and the energy required for transporting the wastes are affected by regional variables, such as the distances between project sites and recycling facilities; social variables, such as regional purchasing habits; and design variables, such as the ease of deconstruction and recycling of construction materials. These variables affect the transportation need of shipping the wastes for recycling, and the percentage of materials that can be “metabolized.” These variables have to be developed into models that would help designers produce better estimates of the embodied energy of recycling and the recyclability of construction materials.