Approximately 60 percent of the weight of all wastes in Germany originates from the building area. For construction activities usually non-renewable resources are used. Nevertheless so far only incomplete knowledge about consumption of resources and energy over the entire life cycle of a building, about effects on consumption of fossil raw materials and the overall ecological implications of the use of recycling materials is available. As the most important decisions are made in the very early design phases of a building, it is necessary to include long-term ecological aspects from the beginning of planning work. Today more and more architects and engineers use CAD software supporting the generation of three dimensional product models. One prominent model being now well established in the building industry is defined by the Industry Foundation Classes (IFC). This model is also the starting point of our resource oriented design system. To get a basis for a comparative assessment of different design variants it is first necessary to augment the product model with informations on resource consumption of the used materials. Therefore a database server accessible via the Internet is developed within our research project providing a service for planners to extend their product model with information necessary for life cycle assessment (LCA). In our presentation the general software concept together with first simulation tools for building energy simulation and life cycle assessment will be discussed.