The telecommunications revolution has done a great deal to lessen the reliance on place and therefor the importance of place. The electronic workplace can be anywhere, with workers at their workstations intimately connected by internet with other workers who could be at distant points around the globe. The tendency to encourage dispersion seems to go in exactly the opposite direction of the modern theory of Sustainable Cities which emphasizes the primacy of place in the negoziation of a sustainable future.

But it also seems that digital technology has a great deal to offer to the development of the sustainable city. In May 1994 in Aalborg, Denmark, the European Charter of Cities and Towns Towards Sustainability was ratified by the mayors and other representatives of Europe's most environmentally progressive cities. Ratification committed these cities to prepare an action plan for the realization of the specifications of the Charter. The management of cities according to the sustainability principles in the Charter will require the development of an altogether new range of tools. Some of the most critical of these tools involve the use of computers. In a general sense the negotiation of sustainability for a city like Vienna, for example, would require an extensive knowledge of all the essential material and energy inputs and outputs of the city as a prerequisite for determining the nature and extent of the unsustainable imbalances. It is difficult to imagine such an extensive study, although a partial study in this direction has just begun at Viennas Technical University. It seems like it would be an impossible task to construct a process which would gather the necessary information on a continuing basis, construct a vast systems model of the actual interactions of these material and energy flows in industrial and domestic processes, as well as setting up an equitable, participatory process of negotiation and consent which would be both believable and acceptable.

At the Center for Sustainable Cities and Oikdrom we have come up with an alternative: the Sustainable City Implantation. This is both a theoretical approach as well as a practical vision for designing and building a sustainable city that absorbs problems from its larger city and exports to the larger city (in the case of our current project, the city of Vienna) a positive sustainability quotient. Our approach relies on the computer in several different capacities: It is used to generate the initial design of the new urban model which is built as a hiltown or cit-as-a-hill. - a modern pedestrian city with many levels of large scale space inside the "hill". In its design process the city is assemled with a large number of changeable and interchangable blocks, so that a particpatory design process managed on the computer offers a great deal of flexibility in the eventual urban design. The computer is also used as the vehicle for a sustainability management process. In negotiating the fabric of the city and t he material and energy flows within and through the city and its industries, infrastructure and economic activities, a systems model provides feedback as to the consequences of any design choices and provides guidance as to whether the emerging city design is moving closer to balance or further away from balance.

Another use of the computer is the creation of a virtual sustainable city. Vital to the negotiation of the form and organization of the Sustainable City Implantation is the necessity of providing feedback as to the consequences of the choices made by the various actors in the sustainability negotiation process. In addition to images of the urban and architectural form, and systems models of tje material flows, more visual models are also possible.

Once the urban/ archtectural models have been sufficiently detailed, animated walk-throughs of the city-in-the-computer may be made. The next step would be the creation of a virtual city. "The Cave", a three dimensional 2virtual reality program, provides the technology of walking or "flying through" the Sustainable City Implantation, and choosing your own path as you go, exploring any and all streets and lanes, buildings and piazzas, and then changing them and visiting them again, each time having the experience of being there. Operating under the processes of sustainability, the city of the future may be developed, negotiated and refined, and a virtual community of its inhabitants may be consolidated, before the city is actually built.