Application of LCA results in the early design phase of environmental-friendly buildings

Buildings are responsible for a significant impact on the environment during their life cycle. For the design of an “environmental-friendly” building, the environmental impacts of aspects including the manufacturing of construction materials, operation and maintenance, demolition and disposal, and related transportation should be analysed from “cradle to grave”. A variety of models have been developed to calculate the life cycle environmental impacts of buildings. However, attempts to find common criteria or principles for design decision making from the results of previous studies is problematic because different studies determine life cycle assessment (LCA) results using a varying series of assumptions and a variety of different parameters. Because of their complexity, LCA quantification methods are not generally employed by building designers at the early design stages when they may be of most benefit. The aim of this study is to elaborate the difficulty of generalising results from previous LCA studies and therefore the difficulty of developing elementary heuristic principles to assist designers, by highlighting the complexity of LCA tool and providing examples of life cycle energy assessment in residential buildings. The results highlight the main problems designers would encounter trying to use the LCA method at the early design stages, and the need to develop heuristic guidelines for designers to allow them to understand the most effective design variables on the building life cycle performance.