2二次订单城市设计US.doc

A Procedural Explanation for Contemporary Urban DesignR. Varkki George Department of Urban and Regional PlanningUniversity of Illinois at Urbana-ChampaignAbstract In this paper, I present an explanation of urban design that tries to make sense of the kinds of tactics used by contemporary urban designers. I argue that urban design is a second-order design endeavor; that is, designers are only indirectly responsible for producing built forms and the spaces in between them; they design the decision environment within which others make decisions to add to or alter the built environment. I first review what has been established in the literature and in practice as the tactics used by contemporary urban designers. I then make my case for why the term second-order design is a good explanation for these tactics. Finally, I conclude with the implications this attitude towards urban design could have for educating urban designers and for conducting research in urban design.A Crisis of Identity? The task of designing urban places-where the designer is primarily concerned with the sensual, but particularly visual, qualities of these spaces-has traditionally been termed urban design. Long associated with architecture and urban planning, urban design in the United States began to acquire a distinct but weaker identity in academia as each of these two disciplines lost interest in the issues that engage urban designers (Dagenhart and Sawicki, 1992). Despite this, urban places continue to be designed in cities across the U.S. even if as Kreditor (1990b, p. 67) points out that there is not an urban design practice carried out by professional urban designers. Also, issues of concern to urban designers continue to be discussed at meetings and conferences of planners and architects, when they meet together and separately. In addition to loss of interest, within academia there appears to be doubts about the status and nature of the urban design task. A leading architecture guru and professor of urbanism is reputed to have declared in the mid-1980s that urban design is pass. There is a sense of diminished importance of urban design among urban planning academics also: Kreditor (1990a) documents the decline of urban design in academia in the past three decades. Dagenhart and Sawicki (1992) cite Gutmans (1988) account of the decline of urban design in schools of architecture and planning, which they attribute to the collapse of discourse between the two disciplines brought about by the divergence of the disciplines. Accompanying these doubts about the status of urban design-and probably in a relationship of mutual influence with these doubts-is a nagging sense that the exact nature of urban design has not been or cannot be specified with any useful degree of precision: If one doubts the immaturity of urban design as a serious field of study, the search for a common definition or understanding will be instructive, for there is none. It is a telling condition. A lack of shared meaning undermines appreciation and retards development. Further explorations are thwarted by slender common ground. Attempts to erase confusion by offering a definition, no matter how well-meaning or profound, nearly always make matters worse. (Kreditor, 1990a, p. 157) Kreditor goes on to posit that a definition of urban design is not prudent because it is bound to be disappointing and because it would stifle development of an urban design discourse. Despite the apparent impossibility of a commonly-agreed definition of urban design, I would argue that a meaningful explanation for contemporary urban design is vital, and that it is worth trying to arrive at one. While attempts to define urban design will in all likelihood not directly or drastically change the work of todays practitioners, I disagree with Kreditor (1990) both that it is an impossible task and that it will inhibit further discussion; in this paper, I will attempt to make the case for this point of view. Furthermore, I strongly believe that a meaningful explanation is crucial to training a new generation of effective urban designers and for inspiring research that can inform the future practice of urban design. For instance, can a teacher tell her or his students, I cannot tell you exactly what urban design is (or, I can only give you a vague description), but I will teach you urban design? What will guide researchers in identifying research questions-other than the obvious questions about the sensual qualities of urban places-the answers to which will help urban designers do their job better?Perhaps the problem lies in the way we have tried to define urban design. The most frequently-used approach is to list the type of projects in which urban designers are typically involved (Shirvani, 1985, p. 1)-streetscape plans, neighborhood revitalization, and so on-with the notion that the definition of urban design is implicit in this list. Kreditor (1990a) defines urban design also-despite his intention not to-but using the converse of this approach: he lists what is not urban design (not large-scale architecture). These sorts of lists leave it to others to glean from their contents the nature or essence of the task. There are available in the literature positive definitions of contemporary urban design, even if these appear to circumscribe the essence of the task rather than provide explanations that can usefully guide contemporary practice. Jonathan Barnett (1982) defines urban design as designing cities without designing buildings; Richard Lai (1988, p. 5) describes urban design as spinning an invisible web. While both these are extremely insightful-a later section will show how closely these abstract descriptions match the kinds of tactics used by contemporary urban designers-they do not provide much guidance as to how an urban designer creates built forms, or why this kind of an approach is necessary. The difference between the less successful and the more successful attempts to explain urban design, it seems to me, lies in the difference between focusing on ends rather than means, on products rather than process, on substance rather than procedure. The basic intent in all attempts to define urban design is articulating its relationship to architecture and urban planning, particularly by highlighting the similarities and differences. If this is accomplished by focusing on products rather than process, then the attempt is likely to get lost in quarrels over disciplinary turf: Are planners really concerned about physical space? How much design is there in a streetscape project? Procedural distinctions are likely to prove sharper and more fruitful; the way planners and architects operate are quite different.In teaching urban design over several years to different groups of skeptical students, I have had to articulate and refine a procedural explanation for urban design that is both sufficiently general and specific at the same time. It is procedural in that it focuses more on the means that contemporary urban designers use to create urban places. It is general in the sense that it is applicable across different situations, and that it is not overly restrictive in what it subsumes. It is specific in the sense that it provides a reason for engaging in specific analytic and synthetic tasks.In this paper, I present my procedural explanation: essentially, I argue that contemporary urban design is a second-order design endeavor; that is, the urban designer is only indirectly responsible for producing built forms and the spaces in between them. Unlike other design professionals, todays urban designers rarely design built artifacts; rather, they are mostly engaged in designing the decision environment within which others (sometimes these are other design professionals) make decisions to alter or add to the built environment. Certainly, this is not a totally new idea. This explanation builds on and recasts-I believe in a more useful way-the ideas of Jonathan Barnett and Richard Lai that were described earlier.In the first section of this paper, I review what has been established in the literature and in practice as the tactics used by contemporary urban designers in the design of urban places. In the second section, I make my case for why the term second-order design is a good explanation for these tactics. I explain why I choose to use this term rather than any other, and I explain why such an approach to design is appropriate given contemporary circumstances. In the final section, I conclude with the implications this attitude towards urban design-urban design as second-order design-could have for educating urban designers and for conducting research in urban design.Before proceeding to the next section, a few points of clarification are in order. First, I intentionally use the term explanation rather than definition because of the normative connotations associated with the latter. While normative theorizing (Alexander et al, 1987; Jacobs and Appleyard, 1987; Shirvani 1990, Chapter 7) has an important role to play in the development of theory, too much prescription is likely to make the body of theories less useful. (Perhaps that is a problem with urban design theory today.) The descriptive theorizing in this paper is directed more towards making sense of contemporary urban design practice than towards postulating the characteristics of good urban design practice. Hence, this paper attempts to explain rather than define.Second, I use the term contemporary to delimit the historic scope of my explanation because words such as modern and postmodern come with too many distracting associations from architecture and philosophy. Shirvani (1990), for instance, uses the phrase post-modern urban design to describe the urban design he saw being practised around him. This immediately prompts such questions as: What is postmodern about urban design? If todays urban design is postmodern, what was modern urban design? While it is not totally clear this was his intent, Shirvani may have been using the term to describe the creation of urban spaces defined by buildings that have all the surface trappings of buildings designed by architects professing a post-modern design philosophy. Finally, the explanation presented in this paper is largely based on urban design in the United States. It is the result of the unique political, cultural, and ideological environment within which urban design operates in this country. There are signs, however, that a second-order approach to urban design is being adopted in countries such as the United Kingdom (Hall, 1996), France (Trache, 1996), and Israel (Alterman and Corren, 1996), albeit of a distinctly local flavor (as it well should be).Describing Contemporary Urban Design With the 1971 San Francisco urban design plan (City of San Francisco, 1971) came a significant change in the way urban designers seek to shape the built environment in cities. Previously, the future urban fabric, as envisioned by the urban designer, was completely described and specified using drawings the way an architect would describe and specify a building. Based on these drawings, builders would execute the construction of the structures thus specified. The work of Le Corbusier in Chandigarh is illustrative of this kind of an architectonic approach. Rather than use an architectonic approach, the urban designers of San Francisco-and in other cities such as New York (Barnett, 1982)-sought to realize their vision of the future by influencing decisions made by the various individuals and organizations intending to alter or add to or the built environment. They attempted to do this in several ways. One tactic was to describe certain maximum, minimum, or otherwise desirable characteristics of individual buildings: the maximum height of a building; the type of uses to be provided. Another tactic went beyond individual buildings to the relative position of different buildings: for instance, they defined view corridors that had to be kept clear of obstructions so as to preserve a significant view; they prescribed an imaginary build-to plane that buildings had to abut so as to create a continuous street wall. Yet another tactic involved not prescription but persuasion: decisionmakers were offered incentives for making certain desirable decisions (or not making certain undesirable decisions); for instance, developers could build additional floor area if they provided an amenity such as a plaza. These tactics, collected and expressed in a document using words and pictures, were intended to ensure that decisions made by different decisionmakers at different points in time would collectively and eventually produce the intended built environment.In the twenty-five years since the San Francisco urban design scheme was formulated, such tactics have been used more widely (Shirvani, 1990), but they have also evolved somewhat in response to lessons learned from previous applications. For instance, in San Francisco, prescription of a maximum building height produced a benching effect since all new buildings were built to the maximum height allowed. Today, a range of heights would probably be prescribed, or some kind of treatment of the tops of buildings required so that the skyline is more varied. Other ways of influencing building design-through the use of design review boards (Lightner, 1992), for instance-are gaining widespread use even if their effectiveness is being questioned (Hough, 1992). Meanwhile, the architectonic approach to urban design may be adopted occasionally (Selby, 1992), but there is a sense that it is becoming increasingly less relevant.Shirvani (1985, 144) provides us with a useful starting point for categorizing the different new tactics used in urban design. He classifies the products of urban design into four categories: policies, plans, guidelines, and programs. These products may give us clues as to the tactics underlying them, but in the process it may be necessary to redefine the meanings of these terms as used by Shirvani. First, policies are broad statements of collective intent that influence specific decisions made individually and collectively. Historic preservation, for example, is a policy that has played a role in several successful urban design schemes. The commonly-agreed intention to preserve a neighborhoods cultural heritage, in its various manifestations, has provided the motivation for specific decisions at the collective level (instituting tax incentives for preservation efforts) and at the individual level (the decision to purchase a piece of property in a historic district despite its dilapidated appearance). The term plan it turns out is less useful as a category of urban design tactics. It is commonly used to describe the document that urban designers produce. This document contains descriptions and explications of one or more of the three other types of products that Shirvani lists. It is more a product in the strictest sense of the term, and no particular special kind of tactic appears to underlie this term. Next, the term guidelines is actually reflective of a broader category of tactics; the term regulations, could be better used to describe this broader category. Regulations, even if as guidelines they are not mandatory, are intended to limit the range of options available when particular decisions are being made by a diverse set of private and public decisionmakers, just as in banking regulation or environmental regulation. Regulatory tactics in urban design include guidelines for facade treatment, but also restrictions on building bulk and prescription of a build-to plane.Shirvani uses the term programs to describe collective efforts to continually maintain and care for the built environment. Used in a different sense, however, this term could also help classify a set of urban design tactics. Programs, in this sense, are the organized and systematic control and deployment or redeployment of collective resources so that individual decisions to add to or alter the built environment are encouraged towards a certain end. A wide variety of programs have found their way into the urban designers toolbox: capital improvement programs, tax increment financing districts, facade easement programs, transfer of development rights, to name a few.We, therefore, have arrived at three categories of urban design tactics: policies, regulations, and programs. Of these three, policies are higher-order tactics that provide the logic underlying regulations and programs; they tend to give coherence to urban design schemes. Regulations and programs are different ways of achieving the same end. While both types of tactics seek to influence decisions, regulations limit the scope of decisions and programs attempt to encourage certain decisions. Regulations are the sticks and programs the carrots that urban designers use to achieve the desired ends (Lassar, 1989).There are at least two ways in which this set of categories must be expanded. First, urban designers must work to develop a consensus about the desired course of action among the different interests involved. Hack and Canto (1990, p. 75) posit that one of the tasks urban designers must carry out is persuading enough (and the right) people of the merit of changing their ways to fit the plan. They then go on to document and trace the gradual but progressive development of consensus among a group of specialists brought together to develop a plan for developing the floodplain of a river running through a city. Clearly, consensus building is an important urban design tactic for without consensus the design scheme would remain only a scheme and not become reality.Attoe and Logan (1989) describe another way of expanding this classification scheme. They argue that urban design practice in the United Stat