For Leske+Budrich Publishers, Hanover, Germany

Towards a Sustainable City

By Beverly Willis, FAIA

Unless we are guided by a conscious vision of the kind of future
we want, we will be guided by an unconscious vision
of the kind of present we already have.
Hugh Barton, London

The 21st century city must be sustainable. It needs to be compact, contain mixed-uses, mixed-incomes, fewer automobiles, and be more "walkable" and green. The city must accommodate its land-use patterns to the life style of its inhabitants — those who prefer urban life to that of other locales. It must use nature to build environmentally friendly buildings that provides the type of space that people need for living and working.

A Changing Society

The 21st century city differs from that of the late 20th century in three ways: social changes due to globalization, the event of a new type of economy, and the feminization of the workforce. These movements create new urban needs that require new urban planning solutions.

Globalization has brought changes to the way in which the corporation is organized, how it works and produces wealth. Globalism ties cities and people together in a new social and economic order. A new global society is being born. The second, the new economy and its needs for the intellectually skilled and technologically adept and the emergence of service industries as a primary source of wealth production changes the characteristics of the workforce. Creative people, the technologically adept and intellectually skilled are drawn to global cities where they find a synergy of skills and common interests that allow them to be successful. The lifestyle of this new urban populace differs from those of the gray flannel suits of 20th century business and industry.

The potential positive and negative effects of globalism and the new worker has been discussed in many recent books, including those by sociologists Manuels Castells and Saskia Sassen, and economists Robert Reich, Peter Drucker, George Gilder and others.

The third change, and perhaps the most important one from the viewpoint of land use, is the feminization of the workplace. As the Hudson Institute (1997) points out, women now comprise 46% of the American workforce (Hudson Institute 1997, 53). Together these events alter the urban society and the way a city needs to be organized to function properly for today’s urban inhabitant.

This new society requires a livable city tailored to its inhabitants’ needs. Accomplishing this will require more than technical tinkering and "tweakage" with existing city patterns. It will require a major change in how we envision the way a city functions. 20th century planning and zoning concepts, for the most part, are obsolete because they no longer relate to how people live and work in cities.

It is the little things that make the city livable, such as clean, well kept, safe, streets; landscaping — trees and flowers — natural light and ventilation; good sanitation and water, accessible public transportation that runs frequently and on time, low levels of eye-smarting pollution, hearing the birds chirp over the roar of the traffic, the convenience of things within walking distance — work, market, cleaners, schools and health clinic — close by outdoor spaces for experiencing nature; and a place to rest and refresh, when one is weary of walking. Little things can be achieved by changing the current land-use focus of public planning to the way people live.

Traditional Role of Cities

Kotkin (2000) notes that while the social and economic core aspects of the city are being altered in unexpected ways, the pattern for change is rooted in the traditional role of cities. (Kotkin 2000, 61)

The city as a center for trade (finance and goods), monumental architecture, entertainment, arts, media, fashion, adventure, and in some instances, the seat of government power, has remained constant throughout history. It is the nature of wealth production that changes and economically determines which cities will flourish.

From ancient times, great cities were founded around ports and rivers accessible to ships. The 19th century railroad created new cities and made ghost towns of others. Automobile mobility made suburban development possible and in the process, drained people and wealth from the cities, some of which are now facing their demise. (Rusk 1995, 14). Today, globalism, digital technology, and jet aircraft are reshaping urban geography and creating new sources of global wealth.

Wealth Production

The city’s well-being, the ebb and flow of its fortune, has historically followed a consistent pattern. As a center for wealth production, the city attracts workers by attracting the type of people who prefer the urban dream to the rural or suburban dream. But the inflow of new people is often accompanied by the out-flow of long-time inhabitants who either have accumulated sufficient personal wealth or that have found the city, as it is presently constituted, inadequate to meet their personal and family needs. Consequently, the city is always in a state of flux. Change is constant.

When industry left the city to find more suitable locations, the wealth loss was replaced by new sources of income. New service industries, such as electronic and digital information technology production, telecommunication, media, culture, tourism, fashion, and advertising industries grew along side of older ones such as finance, commerce, education, health and entertainment. Unlike the metallic, robotic, industrial plants, service industries depend upon people skills for their success.

In the digital era, success primarily stems from the synergy between ideas and the creative ability to implement them. Access to creative skills of art and design and to cultural, educational, and financial resources are traditionally centered in major cities; and worldwide, nations and cities compete for skilled and talented people. To be competitive, cities must provide a quality of life that will attract and keep the type of people, who are the locomotives of the new economy.

In the old economy, people moved to manufacturing locale that provided the greatest number of jobs. While this still occurs, but in far fewer numbers, the skilled worker moves to a place that provides her or his preferred life style. For many, this is the city, even though many others prefer suburban or country living.

Kotkin (2000) points out that today, while businesses can conduct their operations electronically and at a great distance from large cities … the linchpins of urban commerce remain dependent on the sorts of individuals who prefer to live in cities (Kotkin 2000, 61). Today jobs follow people. Attract skilled people and employers will follow them to the city.

Changes need to be made to existing land-use patterns that can improve the quality of urban life, making it competitive with other locales. People — who like city living — like it only as long as it is tolerable.

People choose different types of environments as well as locations as places to live for a variety of differing reasons. Looking at New York City today, a thriving center of media, information and telecommunication as well as finance and entertainment, it is hard to visualize that over 20 years ago it was nearly bankrupt. Roads were filled with potholes; garbage lined the streets; drugs and crime were rampant; and entire neighborhoods were abandoned. The fabled Times Square had become a slum filled with sex shops and drug dealers. People fled the city for nearby suburbs and towns.

Today, Manhattan is a magical place. Tourism is a major industry. Times Square has been rebuilt into one of the glittering wonders of the world. The city has reasserted itself as a world cultural and financial center. Its media center has attracted the technologically skilled. Neighborhoods have been rehabilitated, trees planted, flowers bloom along Park Avenue and the small glittering white Christmas lights, which decorate the winter barren Manhattan street trees, make the city a winter wonderland.

But New York City’s transformative success in Manhattan has led to the same problems that affect other cities around the world. Traffic is choking the city. Higher densities and global tourism mean more pedestrian activity on sidewalks that are already inadequate for pedestrian passage. Truck deliveries have escalated because of catalog and Internet shopping. With no place to park, trucks double park on narrow streets, blocking the normally slow flow of traffic. The bridges and tunnels can not accommodate peak traffic efficiently. People, like canned sardines, are crammed into an inadequate subway system. In short, the city, as it was planned in the 20th century, is malfunctioning. The type of growth has changed.

Growth

Growth has many faces. In America cities, the once rapidly growing population has slowed to a crawl. Land coverage does not relate so much to population growth as to other factors.

Metropolitan area maps, like the illustrations shown here (meld all construction into a single image of land coverage. Figure 1 and 2


Figure 1. 1960 Metropolitan development pattern between Baltimore, Maryland and Washington DC

Figure 2. 1997 Metropolitan development pattern between Baltimore, Maryland and Washington DC

It does not show the growth (or lack of) in the city. While the late 20th century growth of land coverage in the metropolitan area occurred in part from increasing population, much land coverage growth stemmed from the individual’s desire for vastly increased amounts of living and work space.

Population growth varies from country to country. Population growth in the United States and Europe is stagnant and in some cases, it has declined. In Asia, urban populations are increasing. In the United States, it is population shifts, immigration, and the individual desire for more space that creates land coverage growth in both cities (when it occurs) and the metropolitan area.

The land coverage of the metropolitan areas is due to three primary factors. One, as society has grown more affluent, people occupy more living space. The original Levittown suburban houses, the first suburb in America, were designed within 1000 square feet and contained two small bedrooms, one bath and a living room. Today’s typical suburban home is more likely to be 2500-3500 square feet, three to four bedrooms with two or three baths, a large living room, and a dining or play room.

The clone of the same three or four bedroom typical suburban house is less expensive than one located closer to the dominant economic center. The commuter who wants or needs to pay less, will relocate further from the urban center and spend more time traveling a greater distance to work. The pain of the commute is seen as a trade-off for a better and more affordable life style (Mansnerus 2001, 8).

Two, businesses have grown, so have their requirements for more building land. American businesses tried to shrink office space requirements in recent years by cutting the number of square feet allotted for individual use by encouraging employees to live/work, and outsourcing work to other countries. However, Wood (1994) points out that business workspace needs continue to grow (Wood 1994, 150).

Three, from earliest times, world cities have been a center of both migration and immigration with rich and poor alike seeking new opportunities. The shifting flux of inward and outward migrations still continues, as people who follow their ambitions, seek jobs, mild climates, retirement or adventure. What is new is that globalization has changed the character of migration and immigration. The poor, unskilled, and under educated still immigrate to find work. However, as the corporate work structure has changed from a hierarchy to a flattened "pancake", the demand for skilled workers has escalated. Weld (2001) writes that up to 71% of all corporate employees are in top and middle jobs and that foreign-trained administrators, professionals and technologists are filling many of these jobs (Weld 2001, August 22). Additionally, global tourism has boomed. As world wealth increases, so does an affluent, educated middle-class who travel. People from all over explore cities worldwide; some even remain in the cities they visit.

Growth, Decay, and Regrowth

The cycles of city growth, decay, and regrowth have occurred throughout world history. Cites flourished, withered and were reborn. Some have died. Some have changed their names. When cities are reborn or remade, new patterns are created. In 1852, at Napoleon III’s behest, Baron Georges Haussmann constructed wide boulevards through the historical center of Paris. In one stroke, the pattern of Paris was changed in form, size and scale. It was a military matter. Napoleon needed space for troops and cannon to control an unruly population.

Centuries of wars have destroyed cities and altered boundaries. Bombing during World War II gutted many cities, such as Berlin, Rotterdam, London, and Tokyo. These cities were rebuilt using 20th century automobile-dependent land-use patterns, similar to those that shaped American cities — a stark contrast to the small, compact," walkable" medieval cities, such as Amsterdam and Florence, that were not destroyed.

These two patterns resulted in different land-use policies. Amsterdam and Florence closed many, if not all, of the medieval blocks and squares to automobile traffic. Venice closed them all. Crawford (2000) writes that most cities outside of the United States embraced the car with less enthusiasm and altered their urban environments in a less extreme manner. Western Europe planned the flow of automobile traffic carefully, but its cities still suffered considerable damage. While tram tracks were ripped up to pave the way for buses and cars in many European cities, the damage to public transport networks never reached the American extreme, and many cities of any size still have reasonably good public transport systems that are widely used and essential to the smooth function of the cites they serve. As these cities come to grips with the reality of trying to accommodate cars in crowded downtown cores, tram systems are being restored and people are being asked to leave their cars at home when travelling into the city center.

Crawford (2000) points out that highway construction in Europe usually took the form of ring roads, because few cities were willing to consider destroying their ancient city centers and streets. The new ring roads gradually siphoned development way from the center and out to the edge. While this change somewhat diminished the vitality of city’s center, most remain reasonably healthy. Consequently, European centers did not experience the wholesale destruction that was so common in America’s inner cities; and do not have the same inner city problems that exist in the United States (Crawford 2000, 65,66).

Most American cities decayed during the 20th century, because they were drained of their vitality by the flight of citizens to the new post-war suburbs. Lewyn (2000) points out that the national subsidy of automobiles, highway construction, and suburban housing contributed substantially to this occurrence (Lewyn 2000, 296,298).

As people moved to the suburbs so did their jobs. Employers wanted to be close to where their employees lived. Today more jobs are created in suburban towns, than in the city. However, highway design and construction occurred in the era when suburban dwellers traveled to the city to work.

Certain cities, such as New York, Chicago, San Francisco and Los Angeles, are still the dominant center of their metropolitan area, and have become nodes on a global network. Rusk (1995) notes that they are forces in the global economy, while others are still struggling, their future is uncertain (Rusk 1995, 74).

Growth and decay exist side by side. Sociologist Manuel Castells has described the coexistence of flourishing and ravaged areas as "urban schizophrenia". (Kotkin 2000, 14). In New York City, the boroughs outside of Manhattan are still fighting decay. Bringing a better quality of life to all parts of the city is a major issue in developing contemporary land use patterns.

Patterns of Regrowth

To be healthy, large 21st century cities must take steps to create five macro-patterns. One, it must physically separates itself from its edge cities, creating its own well-defined boundaries. This argument opposes the view held by some urbanists, such as David Rusk (1995), that the city must extend its physical boundaries to include the entire metropolitan area (Rusk 1995, 129,130).

Two, as the city traditionally serves as the center of the culture, finance, higher education, health research and specialized medicine, it must create land use patterns that support the growth of these institutions. Castells (1989, 197) points out that in the United States most economically healthy cities have the greatest percentage of highly educated people. The number of college graduates living in cities, such as Washington, DC, San Francisco, Denver, Atlanta, Boston and New York is substantially higher than the average percentage of other American cities.

Three, the city must be economically and socially independent by building on the individual strengths of those who like and want to live in the city. The information economy is bringing people into the cities, not only in telecommunications and information, but in fundamentally creative-driven fields such as media, art, fashion, advertising and design. Global work attracts urban immigrants who are middle-class, well educated and technologically skilled.

Fourth, because of its traditional multi-cultural populations, cities are best equipped with people, institutions and technological infrastructures, which are an integral part of the global economy. Consequently, cities need to continue to incorporate ethnic groups into the fabric of the city and develop a more extensive broadband data information and telecommunication infrastructure.

Fifth, as each city is part of the global environment, it needs to be sustainable as it consumes worldwide resources and contributes to global warming. This means the city needs to adopt an ecologically sound approach to land use, buildings, mass transit systems and be less automobile dependent.

Land Use for the New Working Family

Land-use patterns of the past do not efficiently or effectively accommodate the daily living routines of today’s city dwellers. The traditional family or what social scientists call the "nuclear family" — a father who goes to work and a mother who stays home to take care of the children — is an artifact of the 20th century (Weiner, Brown 1997, 86). The USA 2000 Census showed that for the first time in American history the nuclear family has dropped to one-quarter of all households (Kantrowitz, Wingert 2001, 46).

The advent of the 21st century is not likely to alter the fundamental need for family; but how the family is constituted, as well as its life style and work patterns have fundamentally changed.

Society today is characterized by the "working family". In the United States, 46% of women are in the work force. In 1993 wives were the sole earners in 20% of American married family couples. Women are the sole earners in nearly two-thirds of the families maintained by a single person, or 16% of the labor force. Two-wage families, in which both husband and wife are breadwinners, make up 55%. Gender is irrelevant in the service sector, which will employ the overwhelming majority of Americans in the early 21st century. Women now garner 55% of Bachelor's degrees, 53% of Master's degrees, and nearly 40% of doctorates (Hudson Institute 1997, 52,53). In addition, women have embraced the entrepreneurial spirit. Women's share of small new businesses escalated from 5% in the 70’s to 38% in the 90’s (New American Evolution 1998, 12). Architecture and land-use patterns must fit the needs of today’s working woman.

However, some things never change, like falling in love, having children, or growing old. But for the first time in modern history, women workers have a level playing field; and physical strength is no longer a work necessity. For example, in 1998, Astronaut Lt. Colonel Nancy Jane Currie, Ph.D., wife and mother of an 11-year-old daughter, performed the first in-space task in constructing the first building in space. Using the shuttle’s 50-foot robot arm to lift the construction named Unity, she hoisted the 25,000-pound Unity chamber from the Endeavor’s shuttle cargo 13 feet, tilting it to an upright position in preparation for coupling with the Russian-made Zarya. After the coupling, the two massive earth-built pieces of the space station were bolted together. (1998, Shuttle crew surmounts first challenge in building space station, December, 6).

In another example, Steinhauer (1999) in a New York Times article observes that "By all rights, this should be a perfect time to be a woman in medicine. The idea of women toiling as a most unwelcome presence in the country’s medical schools is long over: women now account for roughly 45% of all medical students, up from about 25% in 1980. And once they graduate, they are in high demand; many patients, especially women, now request female doctors. But despite these gains the top tiers of medicine have remained inaccessible to many women, largely, the experts say, because they are unwilling or unable to find a balance between the years of study specialties require and a life outside of medicine. There are still issues about career pathways that are the least bit off-track, like taking time off for child rearing. But rather than giving up their medical careers for their families, as so many of their predecessors felt forced to do, or forgoing motherhood altogether, more female doctors today are finding ways to practice medicine part-time — as some women in law, journalism, finance and other demanding fields have been doing for years" (Steinhauer 1999, March 1).

They want freedom to miss a meeting occasionally to drop in on a Tumbling Tots class or visit an ailing parent or spend more time with their children or deal with other responsibilities. For example, when Sharon Katz Pearlman joined KPMG Peat Marwick five years ago as a tax lawyer, she wanted to avoid the typical 14-hour days put in by consultants and lawyers and leaves the office when she wished. As a mother of young children, it was important to her "to make potato latkes at Hanukkah for nursery school," so she accepted a lower salary in exchange for a schedule of three and later four days a week. Between the time she spent in the office and the late-night hours at her computer at home, she sometimes worked 40 hours a week anyway. Pearlman said, "I have to be very productive in whatever time I have" (Abelson 1998).

Women want and will have children. Approximately 64% of all married women in the workforce today have children under six years of age. (Hudson Institute 1997, 53).In New York City, the school age population is approximately 1.1 million or 12% to13% of the city’s population. While the child per family ratio is less than the nuclear family suburban average, it is a large number of school children — larger than the entire population of many cities. Certainly large enough to impact land use patterns.

To be competitive in finding skilled women, employers must fully recognize that child bearing and rearing is part of a normal family life. For too long corporations and public officials have looked upon women’s desire and responsibility for children as a business abnormality or inconvenience. In the 24/7 global economy, a woman’s work and family responsibilities, as well as a man’s, do not end at the close of a normal workday. Consequently, services for women-child-family needs need to be located conveniently adjacent to the home, and some, like child and elder care, need to extend beyond the current 9 to 5 work hours.

The question is how can city land use patterns — created by planning and architecture — support working families? One answer is to create living-working environments in which land-uses are arranged so that time absorbed by the daily family routine can be minimized and time with family and children maximized.

The way time is allocated for family, individual relationships, work and relaxation is critical to a family’s well being, productivity and happiness. Time lost in cross-town travel for the daily routine needs; coordination of children's activities (school, tutorials, and recreation); and for health and fitness is unproductive, wasted time. Consequently, land-use patterns that provide convenient spatial closeness, whether vertically in a tall building or horizontally in the block, are critically necessary. Figure 3.

Figure 3. In-city medium density node block

As the majority of the people who live in the city, work in the city, the family can not afford to lose time to cross town or out-of-town commutes. Studies show present commute times within a large city, like New York, averages approximately 42 minutes one-way. (Mansnerus 2001, 1).

Zoning vs. Land Use Policies

Zoning controls the structure of cities. Zoning has divided the city into segregated zones, classified by political theorist Michael Walzer as "single-minded" spaces. Most cities today comprise distinct business districts, industrial zones, shopping arcades, uptown residences, and poor or racial ghettos. In contrast, "open-minded" spaces interweave multiple uses, minimizing traffic congestion and long commute times.

Twentieth century zoning patterns no longer provide a functional urban structure for a city. Public policies, specifically designed to accommodate the characteristics of the city’s inhabitants and their neighborhoods, should be substituted for zoning. Land-use polices should clearly reflect its citizen’s desires on what they want the city to be, such as the height of buildings, the densities of land uses, the ecology, urban form and city identity.

The city organically develops in often unexpected, uncontrolled ways, despite thoughtful master plans or urban policies. It evolves daily through multiple, small individual alterations, an unexpected developer’s proposal, or city-sponsored public works, such as road construction, sports stadiums and convention centers. For example, in New York City, like other cities, many residences have been altered to include home offices. These residential addresses are also business addresses. They are located in almost every section of the city, even if business use is not permitted by zoning. The Mayor proposes a baseball stadium in Manhattan. This is not part of the city’s master plan. Consequently, much of today’s urban construction is result of political negotiation between city officials, developers and concerned community groups. The adoption of urban land-use policies in lieu of zoning recognizes the reality of the present-day urban development process.

People are drawn to the experience of the intimate, small medieval towns with narrow streets, filled with people and dotted with squares and cafes. They enjoy the feeling of "smallness", having a spontaneous coffee or drink with friends and neighbors during the day, catching up on local gossip and activities. This "smallness" contributes to the sense of community and of being surrounded by friends. The "bigness" of the city today overwhelms the feeling of medieval city intimacy. But urbanites still want the experience of the smallness and community. This need seems to be imbedded deep in the human psyche. Consequently, dense cities tend to organically self-organize into community nodes around transportation connections. Figure 4. Shops, restaurants, cafes and services open up to cater to the residents’ daily needs. Community nodes of open-minded spaces need to replace the present concept of single-minded spaces that are obstacles to forming small, intimate communities.

Figure 4. Self-organizing nodes around transportation connections in Manhattan. New York

Node Patterns

Nodes contain homes, offices and all the shops and services necessary for the routine of daily living and need to be sufficiently dense to economically support the shops and services.

Additionally shared social and economic interests, that bring people together, typically create self-organizing nodes. This tends to subdivide the city into "good" and "bad" neighborhoods, and into ethnic enclaves, such as China Town, Little Italy or Harlem. Thoughtful policies are needed to guide this process and assure that this natural process does not exclude mixed-uses, mixed-incomes or mixed-cultures.

Depending upon the size of the city’s population and its density, the city typically is divided into districts. The district is the largest urban node. It may consist of open-minded spaces or it may contain specialized nodes, like government or convention centers, sports arenas, railway stations or entertainment centers or a combination of specialized uses.

Within districts, there are usually a number of communities or neighborhoods. Neighborhoods are divided into blocks. Streets typically provide access to buildings, which usually face the street. Depending upon the density of the neighborhood, it can cover several blocks or be contained in a single, super-block, multi-tower building, such as New York’s Manhattan Plaza Towers building. For very dense cities like New York and Hong Kong a node may be 4-6 blocks in size. Figure 5.

While the city itself is criss-crossed by major thoroughfares, the streets leading to the node should be designed as "access" roads. The node itself should be criss-crossed by street-sized, landscaped pedestrian passages that accommodate surface vehicles, such as bikes and scooters. These passages also need to be accessible to police and fire vehicles.

Figure 5. In-city high density node of several blocks

The hierarchy and character of city streets remain the same, except there are fewer of them. Closed streets become landscaped pedestrian walkways. This necessitates an underground system that not only includes parking, but tunnel-like, truck-sized passages, constructed to allow passage to various buildings or towers on the nodal block. Golf -type carts are typical of the types of vehicle that can be used to transport packages from parked cars or taxi to the elevators accessing living or working quarters. Garbage pick-up can occur underground, taking it off the sidewalks, where it currently gets piled, serving the leg-lifting needs of the neighborhood dogs. Large, heavy item deliveries, like furniture, mail packages, and appliances, also need to be delivered underground, taking delivery trucks off the streets, while they park to make their rounds. Small three-wheel vehicles and bicycles can make daytime deliveries of small items such as mail, packages, and food, using the above ground, pedestrian level passages.

Figure 6. Alternative transportation and city services under node ground level

Development within the district should be coordinated with the mass transit system. Mass transit can be a combination of buses, tramcars and subways. Some form of mass transit should stop at each node. Specialized nodes should be served via subway as they are used by thousands of people from all over the city. Also, since nodes typically grow at intersections of mass transit public policy should encourage this. The advantage of mass transit intersection locations is that they provide a number of travel destination choices without transfers and save time.

As cities evolve block by block, nodes are created through internal regrowth, starting with those areas that need to be reconstructed and continuing each year as more of the blocks of the city are rebuilt. Buildings within a nodally organized city allow new configurations of places suitable for today’s living and working needs. These buildings can be low-rise or high-rise structures in accordance with the city’s density policies.

Specific land-use patterns that are possible are too numerous to describe within the limits of this chapter. Potential design variations within node policies are more numerous than that which is possible within present zoning ordinances. But regardless of height and density, they need to create a sense of "smallness" and community.

For example, movement and passage are as much a part of city life as shelter. A population of 3 to 8 million people means that 3-8 million people will use the sidewalk, street or other types of passageways. As the density of the city grows, so does the density on the sidewalk. As buildings grow taller, there are many more people entering and exiting at the pinpoint location of the building's entry. Add to that, vastly increased international tourism and global business travel, and the neighborhood street becomes a space full of strangers. The intimacy of the neighborhood - the relationship between its inhabitants (families, children and neighborhood storeowners)- still exists, as Jane Jacobs so poignantly described in the 1960s. But the numbers of passersby and strangers to the neighborhood have substantially increased. The sidewalk is now a distinctly public space.

Both the sidewalk and the street, historically, have served as an important place for the use of the block's inhabitants. Today, the public character of the sidewalks no longer serves the inhabitants of the block — they serve "others". New places must be created for the use of the block's residents.

Reacting to the often-cramped quarters of urban living space, occupants in large global cities use sidewalks to escape outdoors for sunshine, fresh air and recreational exercise, as well as shopping. Consequently, on weekends in cities like Tokyo, pedestrians overflow into sidewalks and the streets, making automobile passage virtually impossible.

Widening the sidewalk is one response to increased pedestrian traffic usage. However, the thirty to fifty feet wide sidewalks of New York's Fifth Avenue and Paris' Champs des Élysées can not comfortably accommodate pedestrians certain months of the year. Sidewalk widening exacerbates the problems of congestion. A better idea is to convert streets to pedestrian only usage, reclaiming some of the land devoted to automobility. Although the average ranges from 40% to 50%, Crawford (2000) points out that cars and their related uses occupy up to 70% of city land in cities such as Los Angeles and Houston. (Crawford 2000, 78).

Another approach to providing outdoors’ space for the block’s residents is to reintroduce the courtyard design. Courtyard houses have a long tradition. Examples can be found in every culture throughout the world. In Europe, the courtyard became part of tall building development in the late 19th century. In the early 20th century a number were built in New York City.

The advantage of the traditional courtyard block form is that resident uses are oriented toward the interior court. The public domain, consisting of retail stores, and restaurants, and access to a building’s office and residential floors, is usually oriented to face the public street. Residential access can also be from the court, like some Berlin courtyard blocks.

Courtyard block development can be low or tall in height. Architect Charles Correa (1989) calculates that courtyard housing of three floors in height can achieve equal density to that of medium tall building, e.g., a range of 250 to 1000 persons per acre. (Correa 1989, 49). Consequently, building heights are not a function of density but design choice.

As we think of how to develop node policies, it is necessary now to rethink how nature can penetrate back into the city and become an integral part of the urban landscape. For example, the Peregrine falcons, seeing the cliff-like towers of New York’s high rise buildings, have returned to nest in their parapets, and in feeding their young, have helped clean the city of rats and other rodents. The city needs to restore urban nature in the same manner it restores and protects historical buildings.

Urban land needs to be reclaimed for nature-driven projects and connecting pathways. This will help meet the human need for interaction with nature, create a more livable city and use greenery to reduce global warming caused by the "heat-island" effect of urban construction.

People want nearby access to the outdoors as well as the feeling of smallness within the bigness of a large city. Diverse pockets of nature already exist within the city, such as parks, waterways, rivers and waterfronts, hiking and bike trails. New "found" spaces in undeveloped or underdeveloped lots, unused railroad lines, rail yards, abandoned factories and dead-ends of streets, for example, can be used to connect existing green spaces Green spaces also can be created by closing streets and intersections, landscaping them. In this manner, "ribbons of green" can be created that are accessible to all of the city’s neighborhoods. Introducing more green space helps mitigate building and automobile heat emissions that contribute to global warming.

Urban nature connection between nodes, help provide the feeling of smallness within the bigness of the city. Within the node concept, architects have greater flexibility in creating sustainable, livable, mixed-use, mixed income, building designs.

The 21st century city must be sustainable. It needs to be compact, contain mixed-uses, mixed-incomes, and fewer automobiles and, be more "walkable" as well as green. Its land-use patterns need to fit to the life style of its inhabitants — those who prefer urban life to that of other locales. It must use nature to build environmentally friendly buildings that provide the appropriate space for living and working.

These are major steps towards creating a sustainable a city.

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