The importance of environmental designs has recently increased, mainly due to emerging green markets, required cost savings, and legislative pressure. The Energy-using Product Directive is the most important and urgent legislative pressure to cope with in environmental engineering. Therefore, we investigated this directive in depth. The directive contains essential items and generic requirements defined by the European Commission. Specific environmental design requirements are suggested to fulfill generic requirements, and ecological profiles are required to satisfy specific requirements. The life cycle components of all products are classified into five stages, with each stage requiring its own ecological profile. To fulfill these requirements, we developed a computer-aided environmental design system for energy-using products. Many input items and analysis results were prepared for our system, and several ecological profiles were generated. A personal computer was surveyed by our system as a case study, and its environmental impacts were scrutinized. Our system also allows one to select and compare mechanically and environmentally friendly materials in the advance stages of the design process.