The question of forging a sustainable way of living on this planet is the most significant challenge facing us in the new millennium. The term “sustainability” has been well defined in the abstract, but its operational meaning is still elusive. This is an especially important problem for architects who increasingly embrace the concept of sustainability, but are less than clear about how it relates to the design of buildings and cities. Over the past thirty years there has been a long series of terms that have been used to describe (what should more properly be called) sustainability oriented architecture. Some of them have been: passive solar architecture, energy conscious design, post-fossil architecture, green architecture, ecological architecture and the latest (and arguably the least appropriate) sustainable architecture. Sustainability is a domain that is larger than architecture. Sustainability is understood as an ongoing process through which communities continually renegotiate their common destiny within the limits of nature, their traditions, their understanding of cause and effect and their own creativity. What then does sustainability have to do with architecture? It is the subject of this paper to present an overview of the major analytical methods currently being used in the area of sustainability and their advantages and shortcomings, and contrast these methods with an operational model aimed at actually achieving sustainability rather than describing what we might find if a sustainable city actually existed. In contrast to the analytical approaches that are rooted in scientific tools, this alternative model is rooted in the traditional strengths of architectural design. In so doing the paper also presents an operational definition of “Deep Sustainability” and how the pursuit of Deep Sustainability is dependent upon a design approach.

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Dialog in the realm of sustainability has been largely in the hands of technicians who use mostly analytical tools to map out the territory of sustainability and in so doing confuse the map for the territory. As architects it is important to determine the role of design in such a process. The problem is that while abstract definitions of sustainability are commonly agreed upon, there is as yet no widely accepted operational definition of how to conduct such a sustainability process. Perhaps more importantly, although there are now many descriptions of what we might expect to find as the details of a sustainable society, there is little convincing work in either theory or practice to suggest how we might get from where we are to the realization of sustainability. There is lots of analysis but too little in the way of process or design.

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The most widely accepted definition comes from the Brundtland Commission report (1) of 1987:

“Sustainable development is development which meets the needs of the present without compromising the ability of future generations to meet their needs.”

Although it has several shortcomings the Brundtlandt definition has been the marshalling point from which most sustainability discussions begin. Perhaps the major disadvantage of both beginning and ending our common agreements with Brundtland is that the definition is sufficiently abstract that almost any method or activity that appears to promise positive consequences at whatever scale can be called sustainable under the Brundtland umbrella. It is for this reason that we make the distinction between weak or Shallow Sustainability – i.e. those methods or tools that have the potential for being included within a sustainability agenda and strong or Deep Sustainability: - i.e. those processes that hold the promise of providing a clear set of principles and a method for actually delivering structural sustainability to real world communities.

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Many of the claims that have been made for sustainability are almost exclusively in the realm of shallow sustainability that is possible under Brundtland’s abstract umbrella. It is helpful to distinguish three levels of shallow sustainability:

-NORMAL MAINTENANCE AND IMPROVEMENT:– (Specialized tools for incremental improvement to current conditions.)
Virtues: This is the current way cities are operated. City departments manage and maintain infrastructure and city services which are upgraded as finances permit. Problems are identified by appropriate departments and incremental solutions are sought. Such improvements as may be created through this approach, particularly when they deal with increasing the quality of the public realm, are often called sustainability programs.
Drawbacks: This dominant approach is effective in solving small problems in the short term often at the expense of creating larger, more intractable problems in the long term.

SUSTAINABILITY INDICATORS- (The most popular and often used measuring approach among policymakers here and abroad. It is aimed at incrementally reducing environmental loads in isolated areas.)
Virtues: Focuses on breaking down the whole situation into simpler, sectoral dimensions of urban management. It clarifies stated goals in each area and makes it more likely that specific goals are targeted by specific local agencies.
Drawbacks: As this approach favors “picking the low –lying fruit,” (i.e.- doing the easiest things first,) with each step the path becomes more difficult. It works with many different scales, each scale essentially running from worse to better. None of the scales can represent sustainability. What a set of indicators can show when applied to a city is the relative tendency toward unsustainability in various sectors considered in isolation from one another. In this sense they should be considered “Unsustainability Indicators” as they offer no suggestion as to how or when a sustainability process might be in effect ,in the given town. The indicator approach mistakenly suggests that sustainability is a collection of quantities to be measured rather than an ongoing holistic process.

ECOLOGICAL FOOTPRINT- (Projecting the aggregated territory that is effectively appropriated (consumed) by current patterns of urban metabolism.)
Virtues: This is a quantitative method that is extremely effective as an analytical tool for assessing environmental loads. Metaphorically and visually this approach is a powerful and compelling educational tool to create a public constituency for sustainability programs .
Drawbacks: It is not useful in shaping a solution once the magnitude of the aggregated problem is identified. It typically combines the many pressures on the environment into a single land area based figure, which is typically many times the actual available land area. It answers the question, “How much land area would be necessary at current levels of urban metabolism in order to supply a city with its energy and material needs and absorb its wastes on a continuous basis into the future. (As an example, the ecological footprint of London was calculated by Herbert Girardet to be 125 times its actual land area). In so doing it gives no indication of any appropriate strategy for addressing the seemingly insurmountable problem it describes. Instead it has the tendency to urge stakeholders to embark upon a succession of separate, incremental reductions in the town’s environmental loads, rather than dealing with the town as a whole, integrated system. In so doing it does not recognize city-regions as complexes or as systems and thus it treats causes additively and separately. Because of this it fails to understand and grapple with the synergistic consequences of the many causes of unsustainability and has no way of indicating when, if ever, sustainability is actually achieved.

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In contrast to the Shallow Sustainability approaches described above and in contrast to the abstract nature of Bruntlandt and other definitions, Deep Sustainability can be realized through the implementation of the following operational definition:

“Sustainability is a local, informed, participatory, balance-seeking process, operating within its Sustainable Area Budget, and in so doing exports no negative imbalances beyond its territory or into the future, thus opening spaces of possibility and opportunity.”

The consequence of following this process would be the emergence of a city that effectively removes itself from the global unsustainability equation. If the each human settlement in its turn would initiate the sort of process described in the above definition, thus eliminating the accumulation of environmental loads, the unsustainability problem would cease to exist. A key issue is to establish the minimum scale at which such a local balance-seeking program would be meaningful and at the same time at a scale that is not too large to be feasible to accomplish. Certainly it could not be realized at the scale of a single building – thus the term “sustainable architecture” is clearly an oxymoron. Consideration of many factors leads to the conclusion that the scale at which to design and negotiate sustainability is what it has historically always been – the scale of the city-region.

Because of the importance of establishing the credibility of such an operational definition, the explication this operational definition of Deep Sustainability follows:

“Local” means city-region. City-region means the city as it operates within its “Sustainable Area Budget,” - the total land area based budget that the city-region has to work with on an equitable basis, within which it obtains its resources (on a net basis) and balances out its wastes. In principle each person is entitled to one six billionth of the earth’s bounty on a regenerative basis interpreted as land area. The Sustainable Area Budget (SAB) then, is the aggregation of the budgets of all the members of the community. (There are other factors that may cause the SAB to be applied in somewhat different ways which are dealt with elsewhere(2)). SAB is related to “ecological footprint” approaches, but while ecological footprint answers the question, “How much land area is the metabolism of our city appropriating,” Sustainable Area Budget says, “this is the amount of land to which we are entitled. How can we explore different scenarios for the design of our city and the use of its land to support the highest quality of life among our citizens?” The former is an analytical question, likely to be asked by a scientist. The latter is a synthetic question, likely to be pursued by a designer. While each asks a question relating to land area, the process suggested by each of them is entirely different.

“Informed,” this is the realm of science, but it is also the realm of design. Call it “design science.” In order to be able to make useful decisions regarding the sustainability of cities, it will be essential to first, have a great deal of information upon which to make those decisions. But information alone will not be enough. The sustainable city regions will operate in many of the same ways as natural ecologies, that is, as complex systems. The role of science in such cities will be to build systems models of emerging city design scenarios, in both parts and wholes, to see how various proposals will work as a system within the budget. In the design of sustainable cities it will be too limiting to develop only one design and continue to try to improve it as might be done in a conventional building design or urban design process. Rather computer technology permits the design scientist to carry forward numerous designs and partial designs to be compared and to cross fertilize one another. The systems modeling, scenario-building process permits different stakeholders to put forth their ideas and requirements as what if? (if-then) proposals, to be entered into the systems models to see how they reverberate through the emerging city-system. In this way the problems or imbalances that a local action might create elsewhere in the system are externalized, permitting their consequences to be dealt with. There are two types of systems and systems effects which must be studied together: the quantitative, energy and material flows through the city and its systems and the architectural and urbanistic forms and spaces within which the flows occur – the first one, abstract and analytical, the second, concrete and synthetic. The sustainable system needs a place to happen. In the first iteration, the design of that place may respond in part to the programme of the technical system, but in subsequent iterations it is the emerging families of architectural and urban designs and the stakeholder responses to the emerging city models which will be driving the process.

“Participatory”. In many ways this is the real key, if not the underlying problem. The problem with sustainability is that no one owns the problem. The Aalborg Charter (3) and many other primary sources on sustainability insist on participation and stakeholder process as an essential part of any sustainability program. Scientists are uncomfortable with this provision. Science is seen as an objective process where opinions (particularly non-expert opinions ) don’t count. But in achieving sustainable cities, science is seen as a tool and not an end in itself. Participation has proven itself very effective through citizen action, of preventing bad things from happening, but has been a good deal less efficacious in causing good things to happen. By becoming an integral part of the process, participation will raise the level to the greatest common denominator rather than lowering it to the least common denominator. Sustainability is fundamentally a social and a cultural question and not a technical question. Sustainability is about how a local population, the dwellers of a city region, choose to live within the limits of nature and their own creativity. Designers and technicians will be of enormous help in assisting the citizen stakeholders to make those choices, by testing potential choices before hand and demonstrating what their consequences will be.

“Balance-seeking process,” This is the process of nature – of organisms and natural ecosystems. The system that our global economy has devolved into is an artificial system whose essential shortcoming is that it has built into it no feedback for environmental consequences, social or cultural consequences or indeed for its own long term survival. If it did it would be sustainable and there would be no need for the present discussion. The creation of sustainable city regions will entail designing and managing cities where the major material and energy flows are understood, where cause and effect within the system are understood and where the means for identifying and rebalancing imbalances in the city-system have been provided for.

“exporting no imbalances beyond its territory or into the future.” A city region operating through an informed, participatory balance-seeking process within its Sustainable Area Budget, by this definition will be operating sustainably. It will not be appropriating the environmental space of other city regions. In principle, each city region, as an entity, will be free to do what it will as long as it acts within this rule. Such decision-making processes will take democracy to a new level. Cities will become more differentiated and more different from one another as they respond to the differences in local traditions, landscape, climate, resources, culture, language and their own ideas,

“thus opening spaces of possibility and opportunity.” Our present economy consumes all available space within the city-region – social space, economic space, ecological space, leaving little space within which the paradigm of sustainability might develop. The space of participation opens up the space of negotiation, the space of action and the space of possibilities (moglichkeitsraum in German) whose boundaries are known in ways that are not possible when local economies are fully integrated within the globilization model.

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The above operational definition describes the process of Deep Sustainability as applied to a city-region. Scientists and others with an analytical bent have difficulty in seeing any difference between Shallow Sustainability and Deep Sustainability. They correctly observe that society is not a problem, but that society has many problems and by analyzing them, categorizing them and breaking them down into specialized areas to be dealt with by specialized experts, sustainability will somehow be achieved. Scientists are skilled at assembling the tools and the theories for studying existing complex systems, but this is different from creating complex systems that don’t already exist. That is what good architects are skilled at doing. The pursuit of Deep Sustainability then, is rather a design pursuit rather than an analytical pursuit. But such an endeavor requires good analytical tools which already exist and also modeling and feedback tools which are now being developed.

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The application of the operational definition of Deep Sustainability is currently being carried forth in several research projects. They suggest a role for architecture and for architects that will be greatly expanded from the increasingly marginalized role that architecture now plays. It is both a more demanding role and at the same time a more creative role. As suggested above, at the heart of the sustainability process is a participatory, stakeholder, scenario-building process assisted by professionals that could be called either architects or design scientists. In this computer aided design process (facilitated through a CAD-GIS –systems dynamic program called the Sustainability Engine™ (4)) a succession of city models is designed and tested and multiple alternative scenarios and their consequences are developed and explored through a collaboration between stakeholders and design scientists. This process occurs through a number of iterations where the positive characteristics of the various alternatives tend to be folded together in subsequent scenarios just as the negative characteristics are gradually eliminated. The more this “Sustainability Game” is played the more intelligence is built into the game and the more intelligent the stakeholders and the architects become about both possibilities and consequences. Kevin Lynch once described the city as a “learning ecology.” So too the Sustainability Game is also a learning ecology except that the learning occurs much more quickly and “mistakes” (in terms of unforeseen consequences especially in regard to unsustainable imbalances) are eliminated quickly and many alternative futures may be explored before any actions are actually taken.

Any city is an ongoing project, yet especially in the U.S., city design and development is almost completely piecemeal. Almost every new decision seems to be either an intervention made for private gain or a remedy to correct problems created by previous decisions and interventions. Shrinking budgets leave little in the way of resources to develop amenities in the public realm. This pattern will persist until we have the will and the confidence that we have identified a process that will support both a vigorous economy and an enhanced sense of community through the emotional co-ownership of a process that is likely to deliver an urban environment able to negotiate its balances with the creativity and desires of its people and within the limits of nature. Here is a program that will accomplish that necessary goal. Believe it, embrace it, or transcend it, but don’t imagine business as usual can continue.

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FOOTNOTES

(1) Gro Harlem Brundtland, Our Common Future, The World Commission on Environment and Development, Oxford, 1987

(2) The European Charter of Cities and Towns Towards Sustainability, (The Aalborg Charter,) The European Commission, Allborg, Denmark, 1994

(3) Beyond Sustainability Indicators: The Sustainable Area Budget, Regional Sustainable Development: Making Sustainable Development Visible: Indicators for Regional Sustainable Development,” Graz, Austria, November 2000

(4)The Sustainability Engine™ and the City, Stadtplaene #7, Vienna , Austria, Jan. 1996 “Generating Models of Urban Sustainability: Vienna’s Westbahnhof Sustainable Hilltown”, H. Dumreicher, R.S. Levine, E. J.Yanarella and T. Radmard, book chapter in Achieving Sustainable Urban Form, Jenks, Burton and Williams ed. London:Routledge, Ltd. 2000

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