Life-Cycle Assessment

National Wildlife Federation, Reston, Virginia

The built environment, including buildings, streets, bridges and so on, is constructed from hundreds of materials, products and systems. These materials, products and systems, in turn, are derived from natural resources that are extracted, processed, fabricated, distributed, installed, used, demolished/deconstructed, and potentially re-used or discarded. Life-cycle assessment evaluates the energy and environmental impacts of building materials, products and systems over their entire life, and seeks to inform design teams on building material and product choices that reduce or eliminate these impacts.

A number of life-cycle assessment tools have been created to assist design teams make informed building material and product decisions. Architectural Energy Corporation uses the Athena and BEES modeling tools to quantify the potential environmental impacts of various building materials, products and systems. These tools are used to evaluate and select the preferred materials or systems, from environmental impact point of view, for the primary building systems in a project. For example, life-cycle assessment can be used to evaluate structural system alternatives, such as a steel frame versus reinforced concrete, or an exterior fenestration system or interior flooring. Typically, several key building systems are targeted for life-cycle assessment based on the amount of material used, value of construction or potential environmental impact.