Sustainable Use of Materials - Grey Energy in the Life Circle

Sustainable architecture requires utilisation of sustainable materials. But how can a planner determine which building material is better than another in this respect? How is it possible to make an objective assessment of the complex interrelationships over an entire life cycle? The authors have reviewed building material data bases that are still in the process of development. Orientation aids, such as how material and components can be optimised with regard to the associated grey energy, are provided. The strategy proposed by the authors goes from large- to small-scale, from a building level to a component level. It also includes the type and period of use. Relevant databases for a state-of-the-art evaluation of materials are presented.