Cities As Dense Ecosystems: Cross-Pollination Through Space Design: Micro Renovation and Urban Nature

By Peiwen Yu

Ever since the pandemic lockdown impacted global cities, people have speculated the possible new reality dense cities will face, and the turns of how public spaces may be designed and used. Will cities still be fun for everyone to enjoy and present a collective future for humanity? Some projection says that by 2050, 75% of humanity will end up living in cities. As most people around the world are gravitating to urban areas globally, how we design the cities and adapt to the needs of our changing world really matters. After months of lockdown, urban residents seem to want the streetlife back. Recently, Houston City and downtown officials, spurred by some bar owners and restaurateurs, are working on possible plans to use Main Street for outdoor dining. The idea is to cut off cars from a few blocks of Main to open more outdoor space for selling food and drinks. Added outdoor space could offer just enough room so a few revelers return to what was a bustling corridor before COVID.

About 60 years ago, Jane Jabobs published her celebrated book The Death and Life of Great American Cities, which championed the social aspects of the city, and showed that if cities were to be fun, they needed to be dense ecosystems, with a healthy mixture of components. Jacob believes despite the fact open spaces are highly valued in the city’s planning, the whole point of a city isn’t open space, but rather the ability to bump into exciting people and feed the powerful social instincts that humans have. The use of globally widespread technology may bring convenience to modern life, but what effectively fosters a healthy mixture of people to bump into each other and exchange ideas is how the city is designed.

Coping with the feeling of loneliness and isolation during the lockdown, urban residents have long appreciated the healing effect of contact with nature, and the much-needed social interaction. Jacob’s metaphor of “city as Thriving Ecosystem” explained that an ecosystem needs this kind of cross-pollination if it’s going to stay healthy, which applies to city buildings and where life presents – healthy city streets needed to be dense, varied, and busy. It’s vital to get people out in the streets, instead of some futuristic hubs where people only bump into one another online.

Despite any new reality we may face, density and mixture will still be the solution to make the cities more enjoyable to live in, while actually disincentivizing sprawling and protecting precious Nature. In creating physical spaces for future cities, I see a promising path forward of deliberately restoring the ecology of urban nature while optimizing the social life of dense urban areas through gradual redevelopments, revitalization, and renewal. While looking into the make-up of an ecosystem and succession process, I learn that similarly, what brings magic effect to healthy city building is the mixture of old and new components and an incremental mode of growth.  Jacobs argued that a healthy urban district is like a forest, while a master-planned community is like a field of corn. This ecological perspective on the built environment means that neighborhoods must continually change, bit by bit, year to year so that there is always good diversity. Faster or slower rates of change should indicate a potential problem. For the part of the city that requires renewal, the only way to return to a healthy urban fabric is to incrementally implement small projects, which is called micro transformation. The example projects we’ll explore in the articles are located in some of the busiest cities of one of the world’s most urbanized countries.

Part I: Micro Urban Renovation Projects

The case study below shows a number of placemaking projects that seem to tackle the dense urban public space effectively, creating memorable and refreshing living spaces for the social “cross-pollination” to take place.

YOUNGQING FANG ALLEY TRANSFORMATION (2020 ASLA Professional Award Winner:  Honor Award, Urban Design)

Yongqing Fang Alleyways is a transformation in the urban fabric of Guangzhou’s old town. The design strategy emphasizes the renewal of the buildings and activating existing resources in the area to avoid relocating the original residents. This urban renewal project has improved the quality of life for both old and new residents. Preserving the historical context enables residents to retain their emotional attachment to the physical location. The landscape design and construction were implemented with environmentally sustainable strategies that recreate old city life and reduce negative impacts. With a series of case-specific measures, Yongqing Fang Alleyways has become a successful demonstration of a micro-renovation approach in the old town. (source:


Led by Ma Yansong, MAD recently completed a project to transform a traditional Beijing courtyard into a kindergarten, opening in September 2020. Located on a site that dates back to 1725, the project involves the addition of a floating roof, which surrounds the historic setting and preserves the area’s cultural heritage. The roof transforms the limited space between the various buildings into a colorful playground that functions as an outdoor playground and a place of escape. Below the floating roof, MAD has designed the interior of the kindergarten as a versatile setting that serves as a teaching space, library, small theater, and gymnasium. this openness hopes to ensure a free and inclusive atmosphere, and functions as the daily education space for 400 children between the ages of 2-5. positioned adjacent to the old courtyard, rooms open towards the historic buildings. importantly, the configuration ensures that the site’s three ancient trees are retained. (source:

Another one of  MAD Architects’ ongoing projects, Hutong Bubble 218, spotlights the potential of these ancient neighborhoods in the Chinese capital, which are continually being damaged and demolished due to rapid urban development. “This is a micro-utopian ideal, “said Ma Yansong, the studio’s founder. “I hope that these bubbles will serve as vital newborn cells, giving the traditional hutong new life, and revitalizing the community.” (source:


Nanjing AVIC Science and Technology City is envisioned to be one of the most innovative new communities in Nanjing’s historic core area. With architectural remnants dating back to the Ming Dynasty (1300s BC), the Republic of China (1920s BC), and clusters of existing tree groves, the site presents a unique opportunity for the new development to capitalize on these invaluable features while creating an active new urban landmark with mixed-use programs. At the same time, the high-density new development really challenges the preservation of the historic landscape characters. The design is to maximize the benefits of having both “Old” and “New” coexist harmoniously in building a highly dynamic urban destination, setting an example for similar cases in fast urbanization areas. It incorporates culture and history into new city-building processes, promoting urban energy and dynamics while maintaining a strong sense of place.

The initial phase of the project includes a high-rise office tower and a new Kempinski Hotel that completed construction and opened in June 2020. A renovated historical building has been converted into a clubhouse, located right next to the new hotel. Preserved existing tree groves and a refreshing city garden created a unique landscape that stitches the old and new within this small urban block.

The image above: Initial Phase – The City Garden and Kempinski Hotel Development preserved existing cypress tree groves while introducing a new urban destination at the AVIC new town. The image below: the urban planning work preserved a large number of existing tree groves on site, integrating this distinct historical character into a future development with high density.


The City Garden landscape ties new and old buildings of different scales together with a unifying ground plane and placemaking scheme. The interior design of Kempinski Hotel honors Nanjing’s history as the Ming Dynasty capital with a design that focuses on the cultural interpretation of Ming style and elements. Kempinski Hotel landscape includes the entry elements and roof garden landscape that are small but essential to the activity programs for the hotel operation. The design is particularly focused on the place activation ideas of accommodating multiple types of events throughout the year, balancing designed, intricate garden space with flexible open space that the client may reappropriate later based on particular demands.

the images above: Kempinski Hotel roof garden with urban ecological garden, seating, water feature and open event space.


Part II Resilient Urban Nature and Cultural Heritage

Nowadays, no matter how smart technologies may shape global cities, some of the most magnetic and lyrical cities that attract newcomers are increasingly sharing one simple trait – urban experience is culturally and physically varied, with a memorable expression of local characteristics, region’s history, culture, and identity. The homogeneity has deeply problematic for many cities around the world, and public space creation plays a vital role in building cities of differences.


This recently completed competition involved international class firms and multiple design disciplines in creating a conceptual proposal for a 13-mile-long suburban river corridor located in the East of Shenzhen. Longgang District is undergoing fast urbanization with complicated issues of the water, environment, open space shortage, and industry and culture revitalization. The Blueway Initiative is envisioned to activate the industry and culture of urban communities, unlock the tremendous land value of the watershed, and inject sustainable vitality into the future growth of Shenzhen. The images below show the conceptual design proposal by SWA/BLY/Northeast Institute consortium, named “Big Twist – Celebrating Longgang Nature and Culture”.

The design proposal is inspired by the nature, history, and culture of Longgang. Ecological and humanistic Riverside Districts are created to echo the development of old and new areas. One key design strategy is to enhance the distinct contrast between the ecological riverfront and dynamic urban waterfront, optimizing the urban nature’s ecological benefits while promoting social life in dense urban areas.

The river gives rise to Hakka culture which is reinterpreted and refined by the design of the waterfront. The design concept establishes rigorous ecological restoration agenda, using a number of techniques to gradually build up habitats for target species at the Longgang River corridor.

The waterfront of the urban living room is full of vitality and energy, Design creates artistic murals using the retaining walls of the river embankment to tell the historical stories of the aborigines and Hakkas. In lower-density suburban areas of the river upstream, an immersive natural environment allows workers from new industrial campuses to relax and learn in outdoor areas.

Longyuan Park node integrates cultural and historical relics, and transform out-of-date urban village buildings into an art creative district with a rich riverside experience, keeping some of the old structures and renovating them with artful upgrading and cultural programs.


Photographs in the article by Jonnu Singleton, Xin Sui, Kempinski Hotel website unless otherwise noted.  Nanjing AVIC and Longgang River Blueway projects graphics courtesy SWA and BLY.


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