Rethinking urban density through the Chicago experience: a socio-ecological practice approach


Today, many significant factors, including massive globalization, rapid urban population increase, intense urban regeneration, extensive agglomeration, soaring land prices, and a dire need for land preservation, among others, force cities to build upward. However, many cities lack the experience of integrating vertical density into their urban landscape. Within the socio-ecological practice framework, this perspective essay explains and illustrates recent project examples from the City of Chicago. They constitute an extraordinary leap in retrofitting aging urban infrastructure, balancing the horizontal plane with the vertical one, and harmonizing nature with the urban environment. The paper proposes an innovative “eco-density” theoretical framework to improve understanding of Chicago’s spatial structure and socio-ecological experience.


Wei-Ning Xiang conceptualizes socio-ecological practice as “the human action and social process that take place in specific socio-ecological context to bring about a secure, harmonious, and sustainable socio-ecological condition serving human beings’ need for survival, development, and flourishing” (Xiang 2019, p. 1). Creatively crafted, it views the built environment as a mediator or a facilitator for establishing a healthy relationship between humans and nature. Human activities have substantially damaged environmental and ecological systems; therefore, we have ethical obligations to devise a mechanism to reverse these processes (PUB 2018, p. 3). Recent socio-ecological practice research has been addressing a spectrum of topics, including green infrastructure (GI) and blue–green infrastructure (BGI) (Liao 2019); urban water systems (Flint et al. 2019); ecological esthetics (Steiner 2019); human health (Assmuth and Chen 2019); resilience (Bryant and Turner 2019); landscape performance evaluation (Yang 2019); and the like. This paper intends to reinforce this growing body of research by sharing Chicago’s recent socio-ecological experiences.

Currently, many of the commonly used urban density concepts are based on “statistical formulas” that fail to inform about the social, ecological, and morphological developments of a place. For example, a 50-unit per hectare development could refer to a low-rise or a high-rise environment, while they may have very different morphological and socio-ecological characteristics (Dovey and Pafka 2016). Likewise, population density measures are often inaccurate. For example, the Los Angeles metropolitan statistical area (MSA) encompasses hundreds of square miles of uninhabited mountains in the San Gabriel National Forest, and similarly, the Minneapolis–Saint Paul urbanized area contains several huge lakes. The same problem renders in urban areas that contain, for example, airports, logistic terminals, university campuses, hospital complexes, and railroad yards (Nelson 2019). Overall, there is a need to engage qualitative aspects of urban design and socio-ecology practice when we discuss urban density.

In particular, we need to improve our understanding of how to deal with vertical density as many cities increasingly construct tall buildings. Globally, during the first two decades of the twenty-first century, cities add 13,159 tall buildingsFootnote 1 (50 + m buildings) to the 7804 buildings that they previously built. Construction workers are currently erecting 2816 tall buildings, while developers have proposedFootnote 2 3043 tall building projects. Furthermore, architects and planners have presented 2112 visionaryFootnote 3 projects. Regarding height, before the turn of the millennium, cities built merely 24 supertalls (300 + m/984 + ft buildings), meanwhile they have built over 150 supertalls recently. Counts increase significantly when categories other than the completed ones are included. Cities have also built three megatalls (600 + m/1969 + ft buildings) in the past decade, and they constructed none previously. Further, it took nearly 70 years for the record of the tallest building to increase by 233 ft (71 m), from the 1250-foot-tall (381-m) Empire State Building, completed in 1931, to the 1483-foot-tall (452-m) Petronas Towers, completed in 1998. However, the record of the tallest building was afterward increased dramatically by 1234 ft (376 m) when the 2717-foot-tall (828-m) Burj Khalifa was completed in 2010 (Al-Kodmany, 2018, p. 43). Projecting these figures indicates that cities will host thousands of taller buildings in the future.

However, many cities are grossly unprepared to accommodate tall buildings. The current chaotic proliferation of tall buildings may precipitate another type of sprawl, “vertical sprawl,” with consequences similar to or worse than “horizontal” sprawl. Certainly, the risk of exerting negative externalities on the urban fabric will increase, if skyscrapers are built without considering their environmental impact and ability to adapt to changing economic conditions, social life, population density, demographics, and functional requirements (e.g., Hack 2019, p. 301; Southworth 2011, p. 502; Yeang and Powel 2007, p. 87).

Informing practice: recent examples from the city of Chicago

The City of Chicago is the birthplace of skyscrapers (Hunt and DeVries 2017, p. 34). With its long history and rich experiences in integrating tall buildings and open spaces, Chicago may offer meaningful lessons (Bruegmann 2012, p. 78). As such, this study aims to “dig deep” to identify the spatial structure and recent projects that aimed to improve the sustainability of the city. It attempts to examine the following questions:

  • As a vertical city, how does Chicago integrate social and green spaces?

  • How can the overall structure and pattern of the city balance the verticality of tall buildings?

  • What can socio-ecology researchers learn from the examples provided by Chicago?

  • How can high-rise cities learn from the Chicago’s experience?

  • Can Chicago’s practical projects inform theory?

Renovation projects in Chicago have been focusing on a network of places in the downtown, including the Chicago River, the Magnificent Mile, South Michigan Avenue, the Chicago Loop, Museum Campus, Navy Pier, and the like. Among the remarkable projects are the ones located along the Chicago River and in the Chicago Loop (Fig. 1).

Fig. 1

Source: aerial photograph courtesy of Google Earth (color figure online)

Map illustrates major components of the Chicago’s CBD. The blue line represents the Chicago River. The red line indicates the Chicago Loop; and the yellow line indicates S. Michigan Avenue and the Magnificent Mile.

The Chicago River

The Chicago River is one of the greatest assets in the city. It has supported a wide spectrum of activities, including agricultural, trade, commerce, industrial, and transport, thereby attracting masses of residents, workers, and visitors. When Chicago was incorporated in 1836, large orchards, agricultural fields, and industrial complexes (e.g., slaughterhouses, stockyards, meatpacking plants, tanneries, and lumber and steel mills) grew around the river. In the late 1840s, when the city had a small population of 30,000 inhabitants, the use of the Chicago River as a sewer was not a serious problem. It was a reasonable practice that led to minimal ecological impact. However, when the city rapidly grew to about 500,000 inhabitants in the early 1880s, the drastic increase in population in conjunction with massive industrial developments created serious pollution and ecological damage to the river and Lake Michigan, the city’s source of drinking water (Bosch 2008, p. 45). In 1900, Chicago completed building the Chicago Sanitary and Ship Canal (CSSC), which reversed the flow of the river, solving severe water pollution problems in the lake and river.

While the CSSC has been celebrated as an engineering marvel that solved a vexing problem, saving the lives of thousands of Chicagoans, it caused additional serious ecological damage. As such, treating the river as a sewer for a large population in the second half of the nineteenth century and later reversing the river were both harmful to the river’s ecology. Indeed, the reversal of the river stimulated flooding farmland downstream, invited invasive species, and polluted places all the way to the Gulf of Mexico. In addition, to meet the pressing needs of accommodating larger commercial ships and improving flood control, the river was widened and deepened several times, thereby engendering more ecological damage. Consequently, undoing or reversing ecological harm that was caused by mega engineering projects is certainly a challenging endeavor (Dyja 2014, p. 52; Johnson 2006, p. 23; Hill 2019, p. 7).

Notably, city planners and architects Daniel Burnham and Edward H. Bennett made the Chicago River a focal point of their 1909 Plan of Chicago. They envisioned making Chicago the “Paris of the Prairie,” and to that end, they suggested several critical infrastructure systems and “beautification” projects, including widening roads, integrating new parks, building civic places, and integrating cultural amenities. The 1909 Plan also aimed to alleviate the overcrowding of ships in the narrow river by building several lakefront piers. Out of that proposal came Navy Pier, completed in 1916. Burnham and Bennett also envisioned a magnificent bridge to join urban areas south and north of the Chicago River at Michigan Avenue, already Chicago’s main street. The double-decker Michigan Avenue Bridge (DuSable Bridge) was completed in 1920, and the double-decker Wacker Drive was completed in 1926. The Plan also called for an elegant esplanade lining the river’s Main Stem (Smith 2006, p. 102; Kamin 2001, p. 67).

By the late 1960s, sewer overflows became excessive and the United States Environmental Protection Agency (USEPA) demanded that the Metropolitan Water Reclamation District (MWRD) work harder to clean up the river. In the early 1970s, the passage of the federal Clean Water Act led to planning for the Deep Tunnel system [also known as Tunnel and Reservoir Plan (TARP)], which is designed to hold waste and runoff until it can be safely treated. Construction of the project started in 1975, and it is anticipated to be completed in 2029. TARP should be capable of holding up to 20.55 billion gallons of excess water (Hunt and DeVries 2017, p. 76). While the TARP is treated as a water management solution [designed to reduce flooding and combined sewer overflows (CSOs)], it should also seek opportunities to promote socio-ecological activities along its path.

By the early 2000s, the water and habitat qualities of the river were improved significantly, which in turn stimulated residential and commercial developments along its banks, including a strong wave of tall building construction. Consequently, today, many Chicagoans enjoy living, working, and playing along the river. Several of the city’s most spectacular buildings sit along the Main Stem (Main Branch), thereby creating an unforgettable scene that blends nature with marvelous architecture (Ehrenhalt 2013, p. 11) (Figs. 2, 3).

Fig. 2

Photograph by author

Tall buildings placed along the Chicago River create vivid edges and a memorable path. Note how these buildings create an open-arms welcoming gesture and establish a harmonious relationship with the river for being neither too tall nor short. That is, their verticality complements the horizontality of the river. The iconic Trump Tower at the back serves as a visual terminus. The integrated greeneries along the river’s edges enhance its visual appeal. The photograph also shows a docent of the Chicago Architecture Center on a boat tour explaining the iconic architecture and socio-ecological improvements along the river.

Fig. 3

Photograph by author

A spectacular spatial node occurs at the river’s confluence, where its three branches meet. Among the most prominent buildings is the 333 West Wacker (center). The building’s curved facade complements the bend in the river, and the shades of green in the glass curtain wall reflect the green of the water below. Further, integrated greeneries and trees along the river enhance ecological conditions.

To commemorate the hundredth anniversary of the historic reversal of the flow of the Chicago River, the Metropolitan Water Reclamation District of Greater Chicago built the Nicholas J. Melas Centennial Fountain in 1989. It is located on the north bank of the Chicago River near its confluence with Lake Michigan (Fig. 4). Featuring a tiered, semicircular Modernist waterfall that cascades into a basin facing the river, the fountain incorporates a “water cannon,” which, during the warm summer months, spouts an enormous 24-m (80-ft) arc of water southward every hour for 5 min. The fountain symbolizes the city’s continuous commitment to take care of the river, upholding it as a great asset. That is, the fountain takes up the polluted water of the river, cleans it through the waterfall, and brings back to the river through the water arc cleaner. Further, the waterfall on the north side of the fountain allows visitors to pass under, offering yet another water exhilarating experience. By enveloping visitors with layers of water, this immersive experience mitigates the massive visual impact evoked by imposing skyscrapers. Note how visitors see the surrounding buildings through a “water veil,” thereby mitigating the “urban jungle” image evoked by skyscrapers, illustrated in the bottom photograph of Fig. 4. Overall, Nicholas J. Melas Centennial Fountain represents a “symbolic” example of the city commitment to correct past negative socio-ecological practices.

Fig. 4

Photograph by author

Nicholas J. Melas Centennial Fountain. It features a tiered, semicircular Modernist waterfall that helps in cleansing the river water (top). The fountain incorporates a “water cannon,” which, during the warm summer months, spouts an enormous 24-m (80-ft) arc of water southward every hour for 5 min (middle). It also offers visitors an immersive experience with water. Note how they view the surrounding buildings through a “water veil,” thereby mitigating the “urban jungle” image evoked by skyscrapers (bottom).

Chicago Riverwalk

The Chicago Riverwalk is a significant urban infrastructure retrofit example that may inform socio-ecological practice. By retrofitting disused docks and building under-bridge crossings, the 1.25-mile promenade connects the Lakefront with the Loop (the city’s CBD), uninterruptedly. Brimming with vibrant outdoor social life and full with ecological restoration activities, it demonstrates how integrating the river with social and green places mitigates problems of high density promoted by tall buildings. The Riverwalk accommodates pedestrians and cyclists as well as a wide range of amenities and services, including seating areas, eateries, shops, public art, trees, vegetation, and water features. It also offers a spectrum of social and recreational activities such as fishing, boating, kayaking, and canoeing. Music performances and dance parties entertain visitors.

The Riverwalk’s trees, plants, and native grasses clean the river’s dirty water—their roots absorb and break down pollutants. Cleaner water has started bringing back local fish, birds, turtles, and muskrats. As such, this process is meant to pave the way to establish a holistic ecosystem that invites land aquatic animals, whose also through their natural habits help in removing toxins from the river. Several bird species have been already invited (e.g., mallards, ring-billed, House Sparrow, herring gulls, rock pigeons, American robins, European starlings, and Peregrine falcons). There are also proposals to integrate underwater plant species to attract marine life. The visual esthetic is also enhanced by having greeneries drape over the unsightly river’s steel walls.

The Riverwalk integrates several “urban rooms” or “river rooms.” The “urban room” concept was initially promoted by Daniel Burnham and has been used in multiple projects in Chicago, such as the Riverwalk and Millennium Park (see Sect. 2.3.2). Examples of “urban rooms” in the Riverwalk include the Marina Plaza, the Cove, the River Theater, the Water Plaza, the Jetty, and the Riverbank. The Marina Plaza accommodates restaurants, retail spaces, and public seating areas. The Cove Plaza houses kayak rental spaces, a human-powered watercraft docking as well as eatery places. The River Theater is a tree-shaded “urban oasis” that offers a unique respite for the city’s residents, workers, and visitors. It also serves as a prime location for vertical access between Upper Wacker Drive and the Riverwalk (Figs. 5, 6, 7).

Fig. 5

Photograph by author

Marina Plaza. It is a vibrant place that brings people closer to the river. You find visitors socializing, walking, relaxing, eating, drinking, and sitting on ledges, chairs, boats, and the like. Note how the Riverwalk project has rejuvenated the Chicago river.

Fig. 6

Photograph by author

Like many other places along the Riverwalk, the Cove coalesces “local” nature (resilient, inundation-tolerant plants, water, aquatic animals, and birds), people, and diverse social activities, promoting a rewarding socio-ecological experience. Note how adjacent tall buildings buffer the place from the busy Loop, cast shadow in summer, protect visitors from the wind, and offer visual enclosure.

Fig. 7

Photograph by author

River Theater. It is a strategic place to watch the river’s lively activities (boating, kayaking, canoeing, etc.), to have a private conversation, eat lunch, photograph the river, or play with iPhone. As tall trees attract birds, visitors may also enjoy listening to their twittering (top). Further, the theater facilitates an amazing visual/massing transition between the vertical plane (formed by tall buildings) and the horizontal plane (formed by the river) (bottom).

The Jetty

A significant socio-ecological example is offered by the Jetty (Fig. 8). It integrates floating eco-gardens, rain gardens, and fishing piers that jut out into the river. The floating eco-gardens (or floating wetland islands) incorporate aquatic species and plants native to Illinois wetlands and prairies to support multiple ecological functions, including cleansing the river’s polluted water, removing unwanted nutrients, mitigating flooding, and attracting and sustaining wildlife. The integrated species are water-tolerant, e.g., fox sedge, sweet flag, nodding bulrush, and blue flag iris (Hill 2019, p. 235). Ecologists constructed these eco-gardens from recycled plastic matrixes, which facilitate growing aquatic and terrestrial plants hydroponically. Therefore, plants’ roots are not buried in the soil. They are placed in sponges that soak up river water, enabling them to have intimate interaction with the river water, increasing their function of cleansing water, while water continuously nourishes plants. Plants’ roots also offer opportunities for growing biofilm that functions as a filter for the river water. Further, plants reduce nitrogen and phosphorous levels in the river. As a result, the fish population has already been increasing around the floating eco-gardens, which in turn has been attracting land-water animals such as turtles. The floating gardens are chained together by metal cables and joined to stainless steel pylons elastically to enable the gardens to float and rise up to 8 ft (2.5 m) as the river’s water level fluctuates. Stainless steel pylons have markers to indicate water level (Kinney 2016).

Fig. 8

Photograph by author

Jetty Plaza. The floating eco-gardens (left) and rain gardens (right) promote a substantial socio-ecological learning experience (top). In addition, the Jetty offers visitors a place of solitude, privacy, and intimacy with nature (bottom).

To support subsurface aquatic habitats in this area, fish ecologists used creative intervention techniques. For example, they integrated seven limnetic “habitat curtain,” where each consists of steel frames and steel wire mesh, from which nylon ropes dangle. These are made to make algae grow on them, providing food for fish (Fig. 9). These curtains also offer an artificial filamentous substrate for inhabiting sessile organisms, such as barnacles. Ecologists also wrapped around and attached “pole hulas” to the underwater structural poles, located closer to the walkway. Pole hulas are nylon ropes that promote algae growth and the breeding of amphibious insects, which are major food sources for fish. Further, they installed caisson-mounted “lunkers,” which are porous steel cylinders that offer a place for fish to shelter from powerful river current and aquatic predators, larger fish, and mammals. Fish lunkers were installed on seven of the caissons that are away from the walkway. A 10-in. gap between the lunker and the caisson provides shelter for fish (Fig. 9). Interestingly, these ecological techniques that were implemented in the Jetty were partially inspired by the “fish hotel” project that attracted and provided habitat for river species before the Riverwalk was built (Hill 2019, p. 236).

Fig. 9

Source: City of Chicago

A rendering of the Jetty that illustrates the underwater infrastructure. Fish ecologist implemented creative intervention techniques to promote aquatic life and nourish plants near the Riverwalk.

Therefore, the Riverwalk project contributed to sensible ecological improvement in the river. According to research by Hanson and Callone 2019, p. 2, the Floristic Quality Index (FQI) has increased from 0 to 38.2Footnote 4 in an area of 19,529 ft2. Further, according to Friends of the Chicago River, 40 years ago, only seven aquatic species were present in the Chicago River, while today, over 75 species live there. In addition to serving ecological functions, the floating gardens serve as an outdoor classroom for learning about fish, fauna, and critters. Inviting people to the river makes them think about the importance of their natural and ecological functions. Public programming along the Riverwalk also promotes environmental awareness of climate change, flooding resiliency, and sustainable design. For example, “the 2017 monthly Fish Parades” and “2018 children’s environmental” programs have offered children opportunities to fish and observe thousands of fish, representing dozens of species (Hanson and Callone 2019, p. 9).

The Chicago Loop

Located at the city epicenter, since its early days, the Loop has been a bustling expanse featuring vibrant pedestrian flows, heavy auto traffic, vital public spaces, and stunning skyscrapers. It is home to the City Hall, central banks, national and international corporate headquarters, trading centers, as well as a myriad of shops, restaurants, and other support services. Several public plazas within the Loop create social and green pockets that mitigate problems engendered by massive skyscrapers. In addition to urban plazas, the Loop integrates several important parks, including Grant Park, Millennium Park, and Maggie Daley Park.

Grant Park

By offering a “low-density” green space, the vast Grant Park softens the high-density impact promoted by the Loop’s skyscrapers. With an area of over 0.5 square mile (1.3 km2), this massive park establishes a sound “ecological” relationship with the Loop by creating a significant breathing space that balances the crowded, polluted Loop. The density contrast between the closely clustered skyscrapers and “void” park is splendid. This experience is much appreciated as pedestrians walk from the crowded, busy urban core area into the peaceful park, from a jungle of skyscrapers to a place where nature prevails. Pedestrians enjoy walking into an open green space with vegetation, vendors, music, and, most importantly, people. Streams of pedestrians (walking, jogging, running, sitting, and relaxing) populating the Lakeshore complement a splendid juxtaposition of nature with tall buildings.

Millennium Park

In recent years, the city has retrofitted the northern side of Grant Park with the Millennium Park and Maggie Daley Park. Unlike the spacious Grant Park that was designed to match the city scale, the Millennium Park and Maggie Daley Park were designed to match the human scale. That is, they were designed to be compact with short walkable distances, offering pedestrians great convenience. The design of the Millennium Park embraced Burnham’s concept of small urban rooms where visitors could maximize their visual and sensual experiences as they move from one space into another. Interestingly, these parks are low-density places, but are often crowded with people. Positively, the presence of masses of people near tall buildings humanizes the space, and greeneries of these parks soften the hard appearance of skyscrapers (Smith 2006, p. 54).

Remarkably, the Millennium Park may inform socio-ecological practice. This 24.5-acre (10-ha) public space has revitalized a blighted site, which was once a rail yard for the Illinois Central Railroad, dating as far back as 1852. In the mid-twentieth century, the yard was partially converted into a large surface parking lot until 1997 when the park construction commenced. Today, over half of the park is placed atop a one-million ft2 (92,903 m2), 2126-space parking garage, pedways, and commuter electric train lines. It is touted as being one of the largest green roofs in the world, providing multiple environmental benefits, such as reducing the urban heat island effect, cleaning the air, capturing rainwater, and mitigating flooding (Gilfoyle 2006, p. 89). Advanced horticultural techniques have enabled planting large trees in shallow soil depth, and constructing large rooftop gardens, the case of Millennium Park (Fig. 10).

Fig. 10

Top photograph by author; bottom, City of Chicago

Millennium Park. Over half of the park is placed atop a one-million ft2 (92,903 m2), 2126-space parking garage, pedways, and commuter electric train lines. It is touted as being one of the largest green roofs in the world, providing multiple environmental benefits, such as reducing the urban heat island effect, cleaning the air, capturing rainwater, and mitigating flooding.

The park features abundant open spaces, spectacular public art pieces, iconic pavilions, splendid gardens, and seasonal art displays. These places engage all the senses and consequently compensate for the highly developed downtown area. One of the most notable elements of this area is the beautiful transition one experiences from being immersed in a skyscraper environment to walking into an open green space full of vegetation, vendors, music, and, most importantly, people. The park is accessible to the public, and admission is free of charge. As such, people of various ages, ethnicities, and linguistic backgrounds gather here to interact with the public space, the art, and the various social engagements within the space (Farbstein 2009, p. 89).

As mentioned earlier, the spatial layout of the park follows an “urban room” structure, a concept that was initially promoted by Daniel Burnham. The “urban room” or “imageable room” concept was actualized in Millennium Park so that each space conveys a different design idea. As such, the park contains 12 major “rooms,” including the AT&T Plaza and Cloud Gate Sculpture, the Crown Fountain, the Jay Pritzker Pavilion, the BP Pedestrian Bridge, Lurie Garden, the Boeing Galleries, the Chase Promenade, the Exelon Pavilions, the Harris Theater for Music and Dance, the McCormick Tribune Plaza and Ice Rink, the McDonald’s Cycle Center, and the Wrigley Square and Millennium Monument (Gilfoyle 2006, p. 35). Ergo, “from a user perspective, the park is experienced as a sequence of imageable fragments rather than as a memorable whole” (Southworth 2011, p. 504).

Lurie Garden

Among the significant socio-ecological examples that the Millennium Park offers is Lurie Garden. Designed by landscape architecture firm GGN (Gustafson Guthrie Nichol) in collaboration with garden designers Piet Oudolf and Robert Israel, it is a spectacular 5-acre (2-ha) “prairie oasis” that offers respite from the bustling Loop (Figs. 11, 12). The garden provides not only an enjoyable, solitary space but also blends ecological sensitivity with landscape architecture. By utilizing a medley of plants and natural materials, it creates a memorable cultural experience. The garden hosts over 222 types of plants, including 20 types of grass, 26 types of trees and shrubs, 34 types of bulbs, and 142 types of perennial herbaceous plants. This is remarkable since these plants are “squeezed” in a relatively small area, just 2.5 acres (1 ha). Lurie Garden’s plants are largely native to North America and Illinois (Lurie Garden). To further root the garden in place, the designer chose Midwestern limestone for many of its features, including stairways, stair landings, wall coping, and wall cladding.

Fig. 11

Lurie Garden. By integrating thousands of plants, this “prairie oasis” offers visitors an immersive socio-ecological experience. The contrast between nature in the foreground and skyscrapers in the background is stunning. Photograph by the author

Fig. 12

Photograph by author

Lurie Garden. It is also rewarding to see gardeners taking care of the garden using traditional gardening techniques.

Lurie Garden is a four-season garden. It contains a rotating inventory of distinctive vegetation types specifically chosen for each of the four seasons, enriching visitors’ visual and ecological experience. “In early spring, sun-hungry bulbs and perennials stretch through soil and begin anew. Summer and fall teem with the flutter of butterflies and birds. Winter’s seed heads and ornamental grasses capture snow and ice, creating graceful art forms” (Lurie Garden). In midsummer 2017, the garden hosted a variety of plants, including the queen of the prairie, fleabane, knautia, blazing star, wild quinine, white dragon knotweed, phlomis, mountain mint, and betony (Fig. 13). By offering a rich plant palette of varying color and texture (mostly indigenous) and inviting people of all walks of life, Lurie Garden offers a living socio-ecological “museum.”

Fig. 13

Photograph by author

Lurie Garden. In midsummer 2017, the garden hosted a variety of plants, including queen of the prairie, fleabane, knautia, blazing star, wild quinine, white dragon knotweed, phlomis, mountain mint, and betony.

Lurie Garden’s chemical-free environment, along with the wide range of plants, invites and supports a host of animal species (e.g., 25+ species of birds, rabbits, and squirrels), beneficial insects (e.g., butterflies, moths, bumblebees, honeybees, beetles, grasshoppers, and katydids), and some arachnids (e.g., spiders). As such, it has become a socio-ecological laboratory that invites students to learn about native vegetations, plants, and species (Fig. 14). Visitors can learn, through examples, how ecological gardens can benefit humans while reducing environmental impact. Internally, Lurie Garden, with its botanical and ornamented grasses and native plants, provides a splendid contrast to the rest of the Millennium Park and Grant Park, which they feature spacious tufts of formal plantings. Further, the organic garden provides a marvelous contrast with the city’s orthogonal grid. Collectively, the garden offers an experience of immersion in a robustly textured natural environment, paying homage to the City’s motto, “Urbs in Horto” (City in a Garden) and its transformation from a flat marshland to a bold and innovative green city (Gilfoyle 2006, p. 32).

Fig. 14

Photograph by author

Lurie Garden engages thousands of students and visitors with an extensive socio-ecological learning experience, where they enjoy taking close-up pictures of insects, bees, butterflies, and the like.

Besides observing and interacting with plants and animals, not found in the surrounding urban environment, Lurie Garden offers visitors a linear pool, where they can enjoy intimacy with water. Visitors may take off their footwear, roll up their pant legs, and dip their feet or toes in the water. This experience is greatly appreciated in Chicago’s hot summer. The pool is accompanied by a boardwalk (wood deck), which offers a perfect path to casually stroll and appreciate the natural landscape (Fig. 15). Called the “seam,” the pool stitches together the two main parts of the garden, the light plate and dark plate. Other interesting features include two 4.5-m (15-ft) “shoulder” hedges that run parallel to the two edges of the city’s skyline (Fig. 16). As such, these tall hedges help to partially screen the garden from the gleaming skyscrapers nearby. Hedges also provide visual enclosure, seclusion, and solitude, and at night, they are dramatically lit. Further, they provide an “ecological” transition from inhumanely tall buildings to the pedestrian scale of the park. The “shoulder” hedges symbolically represent Carl Sandburg’s famous description of the “City of Big Shoulders” (Gilfoyle 2006, p. 112).

Fig. 15

Photograph by author

Linear Pool, Lurie Garden. Placed along a diagonal boardwalk, it is a 5-ft (1.2-m) wide, shallow pool that engages visitors with water intimacy experience. Here, visitors may take off their footwear, roll up their pant legs, and dip their feet or toes in the water. This experience is greatly appreciated in Chicago’s hot summer.

Fig. 16

Source: Lurie Garden

Lurie Garden, site plan.

Maggie Daley Park

Maggie Daley Park (MDP) is located immediately east of Millennium Park. It integrates spaces with activities that cater to visitors of all ages to enjoy, relax, and play. The park is composed of hills, valleys, and vistas that animate the space and shield visitors from sun, wind, and traffic noise. The park’s curvilinear and intricate topography contrasts well with the city’s flat and gridded character, and its relentlessly heterogeneous space complements that of Grant Park’s formal layout. The organic nature of the park also complements the rigid appearance of the glass, steel, and concrete skyscrapers that surround it, helping to mitigate the overwhelming verticality of these structures. The park humanizes the space and the city’s skyline works as a spectacular backdrop. Another positive aspect of this design is the noise-canceling effect that the hills provide.

City Hall’s Green Roof

Chicago has been a pioneering city in integrating green roofs in tall buildings. In 2001, it demonstrated one of the earliest examples of green roofs right in the 11-story City Hall, located in the Loop. With an area of 38,800 ft2 (3605 m2), the green roof hosts over 20,000 plants of more than 150 species. The planting palette provides a wide variety of plants, including native prairie and woodland grasses, forbs and shrubs, hardy ornamental perennials and grasses, as well as two trees (Fig. 17). Full with flowering plants along with two hives, the green roof has created a microenvironment that entices bees—beekeepers harvest rooftop honey twice annually, totaling about 200 lb (Chicago City Hall). Overall, green roofs offer multiple benefits. They improve the thermal performance of buildings by reducing the required cooling of interior spaces in summer and heating in winter. They also enhance roof membrane life span, fire resistance, sound insulation, marketability, and the ability to turn wasted roof space into various types of amenity spaces. Green roofs filter particulate matter from the air, retain and cleanse stormwater, and provide new opportunities for biodiversity preservation and habitat creation. They generate esthetic benefits as well as reduce the urban heat island effect, which contributes to overheating and air pollution.

Fig. 17

Source: City of Chicago

City Hall’s Green Roof, Chicago.

From practice to theory

The aforementioned project examples offered by the City of Chicago may inform and inspire about ways to enhance the overall experience of a high-rise city. These projects span over 25 years of design and implementation and they have been compensating for socio-ecological shortcomings that have lasted for almost a century. The examined projects indicate that new open spaces attract visitors, breathe life, and bring balance to the cityscape. Older and new tall buildings have been largely enhancing the imageability of the city and its iconic skyline. A pressing question arises: How can we theorize Chicago’s experience? A theory is needed to help sharpen understanding of the urban design practice and to ease transferring Chicago’s experience to other cities.

A review of urban design literature reveals a knowledge gap in remedying the ills of the high-rise environment. Scholars have written at length about the many problems promoted by vertical urbanism, but fewer wrote about finding solutions (e.g., Alexander et al. 1987; Banerjee et al. 2018; Gehl 2010; Cullen 1996; Fathy 1969; Jacobs 1961; Lynch 1981; Kunstler and Salingaros 2001; Mumford 1961). Planning organizations and urban design movements, for example, New Urbanism (e.g., Calthorpe 1993; Duany et al. 2009; Talen 2009 and 2018); Environmental Design Research Association (e.g., Sanoff 1991; Nasar 1998; Rapoport 1997; Weidemann and Anderson 1979); Societies for Studying the Traditional Environment (e.g., Alexander et al. 1977; Kostof 1991; Rapoport 1997; Riley 2017); and Landscape Urbanism (e.g., Waldheim 2016), largely stress the social pitfalls of vertical urbanism. They argue that high rises are individualistic, introverted structures that make people feel they are living in “vertical silos,” physically, socially, and psychologically. They separate tenants from the social life outdoors, detach tenants from street life, reduce tenants’ participation in public spaces, and weaken propinquity.

Likewise, much of the research on tall buildings has focused purely on building’s issues such as structural systems and materials; mechanical, electrical, and plumbing (MEP); technological innovations and smart materials; artificial intelligence (AI), robotic construction, and digital modeling (e.g., Ali 2020; Ali and Moon 2007; Baker et al. 2009; Boake 2017; Nawy and Scanlon 1992; NEHRP 2002; Sanner et al. 2017; Schueller 1996; Schumacher 2017; Giachetti and Gianni 2019; Perez et al. 2019; Trabucco 2020). Some studies have addressed other topics such as wind and hurricane resistance, earthquake resiliency, vertical transportation, facade design, green walls, safety, security, terrorist attack, and evacuation response (e.g., Alaghmandan et al. 2016; Condit 1988; DeLuca and Foster 2019; Dutton and Isyumov 1990; Ghosh et al. 2005; Grange and Savage 2018; Hadjisophocleous and Noureddine 1999; Hlushko 2004; Isner and Klem 1993; Meacham and Johann 2007; Wood 2014; Wong et al. 2016). Other research has focused on retrofitting tall buildings, analyzing affordable housing policies, and examining building codes and regulations (e.g., Al-Kodmany 2014; Baldridge 2019; Katz 2020; Goldstein and Salvia 2019; Gregory 2003).

Therefore, a significant knowledge gap at the nexus of tall buildings and socio-ecological research prevails. In response, this perspective essay proposes engaging two important models: Kevin Lynch’s imageability model and Ian McHarg’s “designing with nature” model.Footnote 5 Due to the universality and practicality of these paradigms, they have the potential to provide a useful conceptual model that helps to advance the socio-ecological research thesis. The significance of McHarg’s contribution to ecological studies is profound.Footnote 6 “The last 50 years of landscape architecture and environmental planning belong to Ian McHarg. In theory and practice, no designer has done more to stoke the public imagination or reshape the professions around the environment” (Fleming et al. 2019). Likewise, Lynch’s workFootnote 7 continues to be “a touchstone, a foundational work to which scholars and practitioners over five decades have felt compelled to return to evaluate and assess the design and planning professions as they move forward, as that progress is reflected in new scholarly books” (Rosenbloom 2018, p. 213).

Lynch proposed five elements (landmarks, paths, edges, nodes, and districts) that “encapsulate the key elements of a city pattern as sensed by users” (Banerjee et al. 2018, p. 214). They are essential in establishing a positive perception of a place and reinforcing a visual order. Lynch defines landmarks as physical objects that are easily distinguishable from one another and that serve as well-known reference points. He also defines paths as “the channels along which the observer customarily, occasionally, or potentially moves” and nodes as “the strategic spots in a city into which an observer can enter, and which are the intensive foci to and from which [one] is travelling” (Lynch 1960, p. 47). Lynch also defines edges as boundaries between objects, forming linear breaks. Finally, he explains that when a node or a path increases in size substantially, it forms a district. Districts are parts of a city that have common, identifying characteristics (Al-Kodmany 2017, p. 27).

Therefore, by engaging the socio-ecological research, theoretically, Lynch’s five elements become “socio-ecological” nodes, paths, edges, districts, and landmarks. And inspired by McHarg’s work, this study proposes the “eco-density” concept to guide in orchestrating these five elements. Eco-density acknowledges that cities are living organisms that experience unique changes and interactions. It aims to harmonize relationships among a multitude of elements, including humans, nature, and the built environment. In the term eco-density, “eco” refers to a balanced, symbiotic relationship between these elements with a focus on horizontal and vertical planes. Socio-ecological features, found in the Riverwalk (e.g., the Jetty), Millennium Park (e.g., Lurie Garden), and the City Hall’s green roof, help to mitigate the negative aspects of density. They bring nature right in busiest spots and foster social life, exemplifying the socio-ecological thesis. As such, a socio-ecological master plan could help to better deal with vertical density by clustering tall buildings around socio-ecological nodes. Lynch’s five imageability elements could help in shaping the spatial structure of the city. Consequently, as a working definition, this perspective essay proposes that eco-density is:

the art and science of establishing harmonious spatial relationships between the horizontal and vertical planes to form a socio-ecological web of vivid paths, edges, nodes, districts, and landmarks that supports design with nature.

The following discussion operationalizes the eco-density definition. It acknowledges Lynch’s notion that the imageability’s five elements are not found in isolation. Instead, they are part of a web, a network, or even a system. For example, a district could contain a network of nodes, paths, and landmarks, while edges could form a path that contains landmarks, and so on (Fig. 18).

Fig. 18

Source: Aerial photograph courtesy of Google Earth

Examples of Kevin Lynch’s Five Elements of Imageability in Chicago Downtown.


Because of their small building footprints, tall buildings can free space on the ground floor for housing socio-ecological nodes. Further, because of their significant height, they can function as landmarks that can help people to better orient themselves in space and navigate complex urban areas. Chicago’s CBD is full of landmark skyscrapers. For example, the outstanding location along the Chicago River and significant height of the Trump International Hotel & Tower, the city’s second-tallest building, make this tower an unmistakable landmark. It serves as a visual terminus when it is viewed from the Chicago River, helping boat riders to spatially orient themselves in the river and city at large (Fig. 2). Likewise, the dark exterior of Ludwig Mies van der Rohe’s 330 North Wabash makes the tower prominent and establishes a pleasant contrast with the lighter colors of the nearby Trump International Hotel & Tower. Similarly, Bertrand Goldberg’s Marina City features an outstanding organic profile that evokes a splendid contrast with Mies’s 330 North Wabash. These three towers create a marvelous architectural symphony that represents distinct, authentic architectural styles. Forming a prominent edge, these towers also can be viewed as a “collective” landmark that helps people to spatially orient themselves in the city. Interestingly, with its green roof, the City Hall is an “ecological” landmark that may function as a catalyst for other green roof developments since it is visible from over 33 taller buildings in the Chicago Loop (Fig. 17). Full with flowering plants along with two hives, the green roof has created a microenvironment that entices bees—beekeepers harvest rooftop honey twice annually, totaling about 200 lb (Chicago City Hall).

Further, 333 West Wacker Drive’s clever contextual design makes the tower fits harmoniously with the river. The tower functions as an “ecological” joint landmark that knits together the Main and South branches of the river (Fig. 3). The building’s curved facade complements the bend in the river, and the shades of green in the glass curtain wall reflect the green of the water below. While 333 West Wacker is always the same building, its skin that faces the river changes as the sun and clouds shift and morph throughout the day. The stimulating Chicago River’s architecture is appreciated and accessible through multiple boat tours by several agencies/organizations (e.g., Chicago Architecture Center, Chicago’s First Lady Cruises, Wendella Tours, Shoreline Sightseeing, Mercury, Odyssey, etc.), privately owned boats, as well as through the water taxi to Chinatown. Most importantly, the river’s iconic architecture is highly appreciated by pedestrians walking along the Chicago Riverwalk, a prominent path. Of course, the Willis Tower (formerly Sears Tower), the tallest building, is a strong landmark. It helps locals and tourists to spatially orient themselves in the city.


A linear dense arrangement of tall buildings could create a distinct physical edge. If the edge aligns with a natural feature such as a river or a lake, it could visually reinforce the natural edge created by water. The Chicago River demonstrates this concept clearly. A series of closely spaced tall buildings create strong edges that help to define the natural edge of the river. In the third dimension, they help also to define the city’s skyline. For pedestrians, these edges create a visual enclosure that promotes comfort and enriches visual experiences. Further, accommodating parks along the river’s edges could function as socio-ecological paths for residents and visitors as well as mediators between human-made environment and nature (see Sect. 3.3.).


Likewise, if two opposing edges are spaced apart by an appropriate distance, tall buildings may create a recognizable, imageable path. If oriented well, tall buildings can also protect people and nature from intense sun, and the path would facilitate natural ventilation. A sound height-to-width ratio (of tall buildings to open space) often results with a spacious path that can accommodate social activities and green spaces, fostering socio-ecological well-being. The Chicago River illustrates the concept of eco-density by forming a balanced ratio between the vertical plane established by skyscrapers and the horizontal plane formed by the river. Tall buildings along the river create strong edges and a legible path (Fig. 2). Their verticality complements the horizontality of the river. They align well with the river’s banks and offer elegant edges. These landmark buildings also feature strong architectural design consistency despite belonging to various architectural schools and eras. Several iconic skyscrapers such as the Marina City, NBC Tower, OneEleven, 77 West Wacker, River Point Tower, Lake Point Tower, and 333 West Wacker improve the visual experience of the river by serving as architectural landmarks. Placed near the mouth of the river, the Nicholas J. Melas Centennial Fountain serves as a socio-ecological node by helping in cleansing the river water and engaging visitors in an exhilarating experience (Fig. 4).

Similarly, the Riverwalk is a path, anchored along an iconic canyon of tall buildings. These buildings buffer the walk from the busy Loop, cast shadow in summer, protect visitors from the wind, and offer visual enclosure. Places or “urban rooms” along the Riverwalk bring together “local” nature (resilient, inundation-tolerant plants, water, aquatic animals, and birds), people, and diverse social activities, promoting a rewarding socio-ecological experience. The path also provides visual/massing transition between the vertical plane (formed by tall buildings) and the horizontal plane (formed by the river). As tall trees attract birds, visitors may also enjoy listening to their twittering (Fig. 7). Indeed, the Riverwalk has already invited several bird species, including mallards, ring-billed, House Sparrow, herring gulls, rock pigeons, American robins, European starlings, and Peregrine falcons. Overall, the Chicago Riverwalk serves as a wonderful socio-ecological path by engaging visitors with numerous social, cultural, art, and ecological activities. The river is no longer a transportation conduit; it is an integral part of the city’s life. Human activities around the river have enhanced the urban scale and mediated the relationship between the verticality of tall buildings and the horizontality of the river.


Clustering tall buildings around green and social places could create socio-ecological nodes that ignite economic activities, improve social life, and foster healthy living. The Riverwalk contains attractive spaces such as the Marina Plaza, the Cove, the River Theater, the Water Plaza, the Jetty, and the Riverbank. For example, the Marina Plaza accommodates restaurants, retail spaces, and public seating areas. The Cove accommodates kayak rental spaces, a human-powered watercraft docking as well as eatery places (Figs. 5, 6, 7). A remarkable example of a socio-ecological node is provided by the Jetty (Figs. 8, 9). It integrates floating eco-gardens, rain gardens, and fishing piers that jut out into the river. In addition to serving ecological functions, the floating gardens serve as an outdoor classroom for learning about fish, fauna, and critters. Inviting people to the river makes them think about the importance of the natural and ecological functions, promoting environmental awareness of climate change, flooding resiliency, and sustainable design.

The Millennium Park is touted as being one of the largest green roofs in the world, providing multiple environmental benefits such as reducing the urban heat island effect, cleaning the air, capturing rainwater, and mitigating flooding. In particular, Lurie Garden is a spectacular 5-acre (2-ha) socio-ecological node. The garden provides not only an enjoyable, solitary space but also blends ecological sensitivity with landscape architecture. By utilizing a medley of plants and natural materials, it creates a memorable cultural experience (Figs. 11, 12, 13, 14, 15, 16). Lurie Garden engages thousands of students and visitors with an extensive socio-ecological learning experience, where they enjoy taking close-up pictures of insects, bees, butterflies, and the like. Further, the natural feel and texture of Millennium Park and Maggie Daley Park complement and soften the hardscape promoted by tall buildings, thereby promoting a healthy “ecological” relationship between tall buildings and nature. The parks’ curvilinear surfaces and organic terrains balance hardscape and straight edges of skyscrapers.

As being part of a larger network, nodes could function as places that connect multiple paths, hence promoting vigor, energy, and ultra-active social life. As such, Chicago’s CBD contains several important nodes or “urban oasis” that connect multiple paths, thereby offering vibrant social activities and rejuvenating natural experiences. Examples include 311 South Wacker Plaza, Chase Plaza, and Aon Plaza, located right in the Loop’s epicenter. As explained earlier, recently, the Riverwalk has added several important “urban rooms,” including the Marina Plaza, Cove, River Theater, Water Plaza, Jetty, Riverbank, and Vietnam Veterans Memorial.


Finally, at the macroscale, careful clustering of high rises could form a legible district. A high concentration of human activities in these districts renders them as hubs and business centers, i.e., central business districts (CBDs). A dense clustering of skyscrapers creates an imageable CBD, vividly seen and appreciated on the skyline. On the ground floor, dense clustering shortens distances, fostering spatial connectivity, and walkable distances. Despite the “gigantic” image that the Chicago Loop evokes, it is not larger than a square mile. However, its dense arrangement fosters walkable spaces. For example, prominent features, such as Grant Park, Millennium Park, and Daley Maggie Park, are within 10–15 min walking distance from almost any point in the Loop. Short distances also make it easier to access intermodal stations on foot within the CBD, for example, CTA bus and train stations. The Riverwalk has reinforced walkability of the downtown and connected several important functions, activities, amenities, and facilities. Similarly, in addition to leisure activities, people use the Riverwalk to connect to major intermodal transport hubs.

Overall, emphasis on walking prevails for numerous reasons, including health benefits, social interaction, environmental well-being, and energy savings, to name a few. Dan Burden (2014), an expert on walkability, makes a good point, “Walkability is a word that did not exist just 20 years ago. We made walking so unnatural that we had to invent a word to describe what we were missing … Essentially, walkability is allowing people to do what the human body was designed to do in the first place: to go places without having to get into some mechanical instrument.” Walking is the simplest form of exercise; people are pedestrians by design. In his book Walkable City: How Downtown Can Save America One Step at a Time, urbanist Jeff Speck (2013, p. 38) poetically explains the importance of walking by stating: “As a fish needs to swim, a bird to fly, a deer to run, we need to walk, not in order to survive, but to be happy.” A daily walking routine of 20 min can prevent heart disease, diabetes, depression, and some cancers.

Therefore, within the socio-ecological framework, the proposed theory attempts to improve the applicability of the work of both Lynch and McHarg. It advances their theories by integrating and intertwining morphological, social, and ecological dimensions. This revival may enable us to better analyze and synthesize spatial relationships (horizontal and vertical planes), as well as examine the social and ecological implications. The introduced eco-density concept helps to knit together the five urban imageability elements with socio-ecological dimensions. This is clearly evident in the proposed definition. Eco-density is “the art and science of establishing harmonious spatial relationships between the horizontal and vertical planes to form a socio-ecological web of vivid paths, edges, nodes, districts, and landmarks that supports design with nature.”

Concluding remarks

This perspective essay shares with planners, architects, urban designers, social scientists, and ecologists synopses of recent projects by the City of Chicago. It attempts to illustrate efforts to improve socio-ecological conditions after years of deterioration. The paper also theorizes Chicago’s experience by devising an innovative, qualitative “eco-density” concept that could help to examine and integrate tall buildings and open spaces in a manner that is supportive of socio-ecological well-being. The theory suggests establishing density equilibrium by balancing the vertical plane (represented by tall buildings) with the horizontal plane (represented by socio-ecological places). Owing to their great height, skyscrapers not only defy the human scale but also create potentially stressful environments. Parks and open spaces can mitigate these problems by harmonizing the urban with the natural, providing places where people can come together to enjoy social life while being immersed in natural beauty. Public parks and open spaces elevate our sensibilities in regard to the natural environment, reminding us of the benefits that greenery can bring to our dense cities.

Tall buildings will continue to be important elements of the twenty-first-century cities, and therefore, planners need to learn how to integrate them with open green and social spaces. Tall buildings often provide tenants with small living spaces that would necessitate offering them public spaces or “breathing rooms” to play, entertain, and socialize. The high-density, small living spaces inside high-rise buildings should be complemented by spacious public social and green spaces. Substantial opportunities exist to turn abandoned places and aging infrastructure into socio-ecological spaces, as it is illustrated in the examples offered by the City of Chicago, specifically, Lurie Garden in the Millennium Park, and the Jetty in the Riverwalk. Planners should capitalize on these opportunities.

In a nutshell, the proposed eco-density concept sheds light, improves understanding, and complements quantitative urban density measures. By rooting the concept in a socio-ecological framework, it illustrates through examples that planners must engage the qualitative aspects of urban density. In many cases, quantitative measures are incapable of communicating meaningful messages about the built environment. There have been many misconceptions about vertical density in particular. The globe is full of negative examples of vertical urbanism. However, as it is demonstrated by the City of Chicago, a vertical city could promote positive experiences. Therefore, planners must learn “the art and science of establishing harmonious spatial relationships between the horizontal and vertical planes to form a socio-ecological web of vivid paths, edges, nodes, districts, and landmarks that supports design with nature.”


  1. 1.

    Source: CTBUH Skyscraper Center,

  2. 2.


    When a building fulfills all the following criteria, it earns the “proposed” title as follows:

    1.The project has a specific site, an owner, and a developer who are seriously interested in executing the project.

    2.The professional design and planning team has passed the conceptual design stage of the project and are progressing toward completing construction drawings.

    3.The project has obtained construction permission or in the process to do so.

    4.The announcement of the “proposed” building comes from a credible source.

    Source: CTBUH Skyscraper Center,

  3. 3.


    A building project earns this title when it meets one of the following three criteria:

    1.A project idea that does not fulfill the “proposed” criteria mentioned above (the four conditions of a “proposed” project).

    2.A “proposed” project that developers could not advance to the construction stage, or

    3.A project idea whom architects conceived to be an inspirational proposition.

    Source: CTBUH Skyscraper Center,

  4. 4.

    Ecologists consider an FQI above 35 to be “natural area” quality.

  5. 5.

    Renowned scholars have applied Lynch’s theory to landscape ecology (e.g., Annie Palone and Carl Steinitz). However, none has engaged the topic of tall buildings in their studies.

  6. 6.

    “Nothing captures the scope and scale of McHarg’s legacy better than his landmark book, Design With Nature, published in the spring of 1969. It remains one of the best-selling books ever written by a designer, has been translated into Chinese, French, Italian, Japanese, and Spanish, and remains in print today” (Fleming et al. 2019).

  7. 7.

    Lynch’s the Image of the City book has been most influential. It has been translated to about 15 languages; and “was recently in its 37th printing and has sold close to 250,000 copies in English, a testament to its popularity” (Banerjee et al. 2018, p. 214).


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The author would like to deeply thank the journal’s reviewers for useful feedback. Great thanks are also due to the journal Editor-in-Chief, Professor Wei-Ning Xiang, and Guest Editor, Professor Xinhao Wang, for helpful directions, detailed comments, and encouragement to revise and resubmit the paper. The author would like to sincerely thank both professors for invitation to present the paper in the Tongji-GLUT (Guilin University of Technology) advanced lecture conference that was held in Guilin, China in May 17–19, 2019. Further, I would like to thank Professor Greg Lyndsey and Professor Jachna Timothy for insightful comments on the presentation.

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Correspondence to Kheir Al-Kodmany.

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Al-Kodmany, K. Rethinking urban density through the Chicago experience: a socio-ecological practice approach. Socio Ecol Pract Res 2, 131–147 (2020).

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  • Tall buildings
  • Urban density
  • Spatial planning
  • Urban design
  • Open spaces
  • Chicago
  • Socio-ecological practice
  • Socio-ecological practice research