The airport Berlin Tegel is going to be closed down. TXL will be developed as a high quality research, industry and business park with the profile of 'urban technologies'. A strategic masterplan builds the foundation for a flexible - and therefore, robust - planning process. Developmental guidelines and a profound system of rules create a structural, programmatic and creative quality of strategical important subareas. Simultaneously, more flexible developmental options are being allocated for other areas. ‚Quarters' profiles' emphasize exisiting potentials of subareas and strengthen the specific identity. An integrated concept for energy and water supports the sustainable development: biomass, geothermal energy, wind energy and photovoltaics provide regionally generated energy. Gray and rain water is being collected, refined and reused regionally. An urban aerial railway connects the site with the station and the tram. Here, the aerial railway is not only an efficient, sustainable means of transport but also represents sustainable mobility in terms of the site's profile.