Due to the political, social and economic structural changes of the 90s in various European cities many former industrial or commercially-used areas were abandoned. The negative impact of these areas on the quality of urban life reaches far beyond the site itself. The conversion process of former commercially-used brownfields located in inner-city districts shows that projects of investors are often at odds with the ideas of municipal authorities on sustainable inner urban development. These conflicting interests create a deadlock caused by the existing administrative tools. PROSIDE improves urban development and ensures that natural areas are preserved and run-down areas restored. Quality of life and environmental quality in inner cities will be clearly enhanced by private investors. The project's communication tools are a contribution to the CADSES information society, providing a database for private investors and promoting communication among all municipal departments as well as a better involvement of European society and the relevant socio-economic units early in the development process. The planning tools bring together the objectives of implementing a more balanced social and economic development of inner urban areas, and reducing environmental damage. Furthermore the PROSIDE approach reduces the time frame for future investor-driven planning activities and increases the success rate of privately funded rehabilitation projects. The co-operation of different cities with various spatial conditions in the CADSES area improves the horizontal exchange of experiences in spatial and environmental planning. The co-operation of university institutions with public administration bodies and private companies enhances the direct information flow and know-how transfer between basic research and practical applications.