An approach for handling environmental and economic conflicts in the context of sustainable building

When striving for sustainable buildings, the focus is often set on the optimization of the building environmental impact. In that perspective, the Life Cycle Assessment (LCA) method is widely used to calculate the environmental impact and through comparative studies, the preferred design options are chosen. As costs are however a very important issue in decision making, it is important to include costs in the analysis too. Although decisions are often only based on investment cost, we recommend considering also the life cycle cost (LCC) to guarantee long term affordability. This paper illustrates the importance of considering both aspects by discussing the optimisation of 16 representative residential buildings in Belgium from both an environmental and financial perspective. The question raises how to handle contradictions between the results of an LCA and LCC study of a building. The paper discusses and illustrates the promising approach of monetary valuation of environmental impacts. Recommendations are formulated based on the experience in the Belgian context.