In this series of articles titled Urban Morphology, Blight and Renewal. The first article, Urban Morphology explores the nature of the urban environment and how its many foundational qualities mingle to create something almost lifelike, often referred to as the ‘urban fabric’. The second article, Urban Blight, continues by investigating the forces which lead a healthy urban fabric into a state of dormancy and disrepair. The final article, Urban Renewal, proceeds to suggest how adaptive reuse can revive blighted urban elements by altering their functional and aesthetic qualities to complement the ever-changing urban fabric.
We thank Enrico Pescivolo for contributing to this month’s Unlocking Architecture feature. Enrico was the national finalist for the 35th Corobrik Student Architecture Award in 2021 for his master’s thesis, OBSOLES[S]ENCE: Recharting Humanities Relationship with Technology Through the Adaptive Reuse of the Kelvin Power Station. This essay acts as a prelude to his thesis chapters 2 (The Threat of Obsolescence) and 3 (Adaptation) which form the basis of articles 2 and 3 in this series, respectively.
The distinction between urban and rural can vary from one country to another, and in some cases, within regions of the same country. Many countries or regions have specific population thresholds or other criteria to define urban areas. But at their core, urban environments are characterized by their relatively high densities. Density is central to the literature on urban morphology, planning and policy implementation, but more so it is a guiding principle in the study of human society, our conflicts and their resolutions.
“Urban fabric” is a term that generally describes the structure of a city, town or other dense human environment. ‘Structure’ in this sense is meant as the broader term of morphology, one that encompasses both the tangible aspects of the built environment like parks, streets and squares and the intangible aspects like culture and daily human life that evolves and is evolved by the physical boundaries of any settlement. The morphology of an urban environment can be likened to a fabric. Just like a fabric, the urban environment is supported by many interwoven threads and its integrity depends on the coherency of all threads as a sturdy whole that can be stretched and scrunched without losing its identity. The Urban Fabric, determined largely by human activity, has a lifelike quality and remains healthy so long as the interactions it facilitates can be sustained in the long term.
It is the goal of this essay to explore and clarify the subject matter of urban morphology. It produces a definition of density, contextualises it within the urban landscape and sets a precedent for the healthy urban fabric as a vehicle for sustainable human activity.
Urban environments are typically characterized by a higher population density in comparison to its surroundings. The most obvious way to think of density is from a topographical perspective, defined by the arrangement of physical elements like buildings, roads and parks -that which might be viewed on a geographical map. These tangible factors are easy to observe throughout the built environment but they hardly describe the urban landscape in its entirety. The topological approach to density is far more revealing, taking into account all factors that dictate the arrival and dispersion of densities which shape urban morphology. Included are both the tangible and intangible, like topography, politics, preferences, societal values, history, technology, and the cross-pollination of ideas. This list is not exhaustive and the factors that one needs to consider for a holistic picture of urban change is a matter of constant research.
There is a uni-directional relationship between tangible and intangible densities, that one causes the other and is not caused by the other, but the truth is that their orchestration is dialectical. There is a dynamic interaction between these opposing ideas, wherein their tension, conflict, and resolution drive the transformation of the urban landscape (Levy, 1999, p. 79). Understanding something dialectically means looking for its internal and external contradictions and seeing how those contradictions drive change. So, it is not sufficient to say that the tangible features of an urban environment cause the intangible (the presence of natural resources causing culture), or that the intangible causes the tangible (the cross-pollination of ideas leading to the development of buildings). Although in many cases there might be a unilateral cause between the tangible and intangible, in many more cases both affect one another at different points in time and, oftentimes, simultaneously.
Take the following hypothetical example: the presence of natural resources attracts settlers who create a port, inviting trade from other peoples with unique cultures. They exchange disparate perspectives and, in the process of cross-pollination, the people of the port invent new technologies, if they have not traded for them outright. Such technology could lead to the eradication of plastic waste and the revitalization of landfills into fully-fledged environmental habitats. Furthermore, those habitats, which host a rich playground for the youth, might inspire a new generation of conservationists who go on to create more sustainable urban environments in the future.
Like the butterfly effect, this example highlights how the complex morphology of an urban environment might manifest from subtle sources and affect changes on a larger scale.
Density is more complex still. It extends vertically, upwards through multi-story buildings, bridges and even the air -considering aeroplane, drone, and bird traffic- and downwards to the sewers, mining tunnels, power cables and infrastructure that traverse the urban topography unseen. Density encompasses also the fourth dimension of time. Our biological and societal functioning is largely influenced by the circadian cycle.
(McFarlane, 2016, p. 19) speaks of the interesting case of the City of London.
“…day and night time densities can vary considerably for different urban areas – the city of London, the square mile that marks the capital’s finance centre, has one of the thickest economic densities in the world given its office hour productivity, but fewer than 10000 residents (a third of whom, walk to work) and therefore one of the lowest population densities in the wider city and easily the lowest near the centre.”
There is yet another type of density that influences the flow of traffic within the urban environment, that of e-densities (McFarlane, 2016, p. 25). It cannot be overstated how impactful the internet has impacted the urban fabric. In the digital realm, people interact on social media, attend work remotely and engage in entertaining pastimes. The access afforded by the internet allows us to be in many places at once and from a single point in space, leading to a shift of densities away from city hotspots to residential complexes and surrounding suburbs.
As demand for online services increases exponentially (SRG Research, 2021), there is a proportional requirement placed on infrastructure development. Data centres are the backbone of online interactions that take up a significant amount of space to build and, in their operation, burden the power grid. The effect of e-densities and technology has drastically altered the urban topography and will continue to do so in new and unexpected ways.
Scholars have conducted many studies on urban form but not on its societal and economic implications. There has been a growing gap between the quantity of new urban theories and methods which inform the pragmatic aspects of urban planning like policy implementation (Clifton, K. et al., 2008, p. 17). Urban inquiry must evolve by incorporating multidisciplinary perspectives. One such paper by (Clifton, K. et al., 2008) breaks down a meta-study of approaches to analysing urban morphology into 5 distinct categories and will form the body of this section. Those criteria are landscape ecology; economic structure; transportation planning, community design and urban design.
- Landscape EcologyLandscape Ecology is concerned with how urban spaces impact natural land covers like forests, brush and wetlands and how the impervious surfaces affect water quality. The focus of landscape ecologists is not on patterns of urban expansion but on the preservation and health of the surrounding, undeveloped areas. Types of natural land are broken up into ‘patches’. The edges of these land patches are of interest, as they “engender competition from generalist species, predation, human disturbance, etc.” (Clifton, K. et al., 2008, p. 19), generating biodiversity. Although many smaller patches have a higher edge-to-landmass ratio than a single large patch, certain plant and animal species require large patches to thrive. The ideal natural landmass consists of a combination of both small and large patches in proximity to one another.Considering landscape ecologists’ requirements concerning the size, shape and multiplicity of land patch types, limitations are placed on urban landscape growth. As such the natural environment can shape the size and density of the cityscape.
- Economic StructureTrade is one of the most prominent forces binding people together and, if the city is defined by such togetherness then its ability to enable economic transactions is the incentive that sustains and grows. In the construction of the ideal urban morphology, economists ponder how the types of industries it contains as well as the proximity of those industries, and their constituent business organizations, enable economic efficiency. Such an analysis is enacted by examining the relationship between aspects of the urban population, including average incomes, wages and the cost of public services. Although there is no consensus on the optimal city size for economic efficiency (Clifton, K. et al., 2008, p. 24), studies have revealed a positive correlation between the diversity of industries within the urban landscape and its economic efficiency. This phenomenon is known as ‘agglomeration economies’ and facilitates the sharing of resources, knowledge, and markets, leading to reduced costs and increased productivity. Both monocentric and polycentric models of urban activity can exhibit agglomeration economies, but they manifest differently in each.Monocentric models of urban activity are often associated with the early 20th-century city and hold that economic activities revolve around a single centre, usually called the Central Business District (CBD). Ernest Burgess’s concentric zone model is a classic representation of the monocentric theory. In this model, a city is divided into concentric rings emanating from the CBD. These rings represent different land uses and residential patterns, with the land value being highest at the CBD and declining outwards. The rationale behind the monocentric theory is that businesses want to be located close to each other to reduce transportation costs, share a labour market, and benefit from economies of scale. As a result, workers and residents find it beneficial to live close to this centre, leading to a high demand for land, resulting in higher land values near the CBD. Naturally, individuals will sort themselves into areas where land values and rental prices match their means. In the monocentric theory, wealth begets wealth: if it is economically advantageous to be located near the CBD then those who can afford the higher land values will have better opportunities and with such opportunities, the growth of the urban structure will be biased towards their desires and preferences. Although this has been true in the past, polycentricity shifts the narrative drastically.
The rise of the automobile, suburbanization, and the spatial decentralization of economic activities in the post-World War II era have given rise to polycentric urban forms in many cities. In polycentric models of urban activity there exist multiple nuclei, or ‘hubs’, of densities. Each of these hubs might specialize in a particular economic activity or cater towards specific commercial or residential needs. For instance, one hub might specialize in finance, another in technology, and a third in manufacturing. The term ‘edge cities’ (Garreau, J., 1991) describes significant economic hubs located on the outskirts of traditional urban areas and encapsulates the polycentric paradigm.
While each hub in a polycentric city might function semi-independently, they often remain interconnected. This creates a complex web of agglomeration economies, where benefits accrue not just within each hub but also from the interactions between them, leading to a broader distribution of opportunities and wealth.
The superimposition of the aforementioned e-densities only nucleates a city’s economic activities further, leading to a more economically efficient morphology. It may just be a matter of time and technological progress until the ideal city, at least in the eyes of economists, is revealed.
- TransportationIn the eyes of the transportation planner, individuals travel to arrive at a destination as efficiently as possible. It is the project of the transportation planner to map these destinations to inform the development of appropriate travel routes and infrastructure to improve accessibility and traffic flow. One of the metrics used to assess the performance of roadways, intersections and other transport facilities is the Level of Service (LOS). It is often graded from A (free flow) to F (forced or breakdown flow), reflecting the quality of the transit experience in terms of speed, manoeuvrability, and delay (Transportation Research Board, 2010).The urban landscape is a complex network where the destinations of its inhabitants are the nodes and the lines that connect them are the transportation infrastructure. Tracking every possible node in the urban network, given technological limitations, is too resource-intensive and would need to be reconsidered for every shifting preference. To simplify their work, planners break down the urban environment into Traffic Analysis Zones (TAZs), “assigning current and expected future jobs and households to these zones” (Clifton, K. et al., 2008, p. 27). Each TAZ represents an aggregate of destination nodes, between which the planner can more easily monitor the flow of traffic and plan for future transportation needs. Imagine a new shopping mall is proposed in a particular TAZ. Planners can assess how it might affect traffic patterns in the surrounding zones and propose the construction or extension of new streets, sidewalks, public transport interventions and other kinds of travel infrastructure that might enhance the flow of traffic. That infrastructure then attracts new developments, as the closer they are situated to a road, the less prohibitive it becomes for people to use the building which increases its return on investment. Herein is another example of the dialectical interactions of urban morphology – buildings incentivise roads and roads incentivise buildings.
If the economy is the heart of the city then its roads are the veins and arteries that supply them with oxygen -the people who enliven it. Transportation infrastructure plays a crucial role in urban morphology and, as autonomous transportation becomes widespread and drones take to the sky, will become an even greater contributor to the shape of the city and the interactions that govern it.
- Community DesignUrban environments often attract a diverse population which can grow into institutions, some of which might have conflicting interests. How does one reconcile the needs of disparate groups like religious, cultural and political communities or account for urban growth in anticipation of a boom or decline in population size? The realm of urban morphology at the community scale belongs to land-use planners. They find import in a breadth of urban topology subjects like environmental preservation, economic efficiency, transportation, demographics, schooling and public safety. Although land-use planning borrows from a breadth of urban subjects it differs in its emphasis on group dynamics and their impact on the future of urban development. The field forecasts population and employment growth, using that data to accommodate the needs of forthcoming households and residents. “For this reason, a common measure of urban form at the community scale is development capacity” (Clifton, K. et al., 2008, p. 31) – how well the community can cater to these anticipated changes in population size and the distributions thereof. Planners use GIS (geographic information systems) to accurately consolidate their data needs, enabling land use planners to make more informed, effective, and sustainable decisions.One measure of land-use configuration accounts for the proximity of various groups to important public and private facilities. There is a threshold distance beyond which essential services become inaccessible, negatively impacting quality of life. This distance can vary depending on the availability of transport types. A city that promotes walking and cycling should ensure that public schools are located within reasonable distances and place the appropriate safety measures in risk zones along transit routes.
By visualizing datasets and analyzing spatial relationships, land-use planners view urban morphology as a means of promoting the welfare and prosperity of communities ensuring that the city is sustainable, equitable, and meets the current and future needs of prevailing communities.
- Urban DesignThe highest resolution of all approaches to urban structure is Urban Design. Whereas Community Design caters to the needs of groups, Urban Design serves the individual and considers what aspects of the environment they find attractive or repulsive, planning the cityscape to enhance the experience of space. They account for a plethora of factors including:
- Scale and massing: the size, shape, and height of buildings relative to one another and their surroundings can determine how spaces feel.
- Frontages: how buildings interact with the street, including aspects like porches, storefronts, and front yards can have a profound impact on a space’s visual and emotional appeal.
- Infrastructure: the presence and arrangement of trees, gardens, parks, greenways, and other green spaces within the built environment provide a welcome detour from the bustle of city life.
- Cultural and Recreational Activities: theatres, museums, galleries, sports facilities, and other cultural institutions have their place in the urban landscape, providing venues for cultural enrichment and recreation.
- Residential Life: the layout and design of residential areas, including the mix of housing types.
- Safety and Security: Proper urban design can promote safety, with well-lit streets and clear sightlines for areas that maintain consistent human activity.
- Materials and Architecture: the types of building materials used and the architectural styles present, can impart a particular character or identity to an area.
- Social Interaction: perhaps the most crucial of all elements in urban design, and the one which affects and pervades all others, is social interaction. In the densities of urban life, contact with people is unavoidable. Although a high population is good for a city because it promotes diversity, too much density equates to congestion, not just of people but of emotions that can fuel conflict and strife. Thus good spatial management must find a balance between public exposure and privacy. At its core, the urban fabric is a vehicle for human activity. The arrangement, design, and interrelationships of buildings, streets, public spaces, and other elements of the urban environment are all tailored to accommodate and promote a wide range of human activities, from the mundane to the extraordinary.
There are numerous challenges facing urban designers but few are as disruptive as the proliferation of automobiles: “…most design elements became focused on experiencing urban space from the inside of a car. Signs are large, buildings are set back from the street and trees are trimmed to allow traffic signals to be easily viewed.” (Clifton, K. et al., 2008, p. 34). In areas with high amounts of vehicle traffic walking has become a less attractive option due to a decline in access, safety, and beauty, owing to an increase in noise and pollution. The Urban Planner might resolve these issues by proposing buffered sidewalks and using trees, planters, or bike lanes to protect pedestrians from fast-moving vehicles. They ensure that crosswalks are frequent, visible, and safe. Pedestrian signals with adequate crossing time and refuge islands on wider roads can help. They integrate parks, squares, and green spaces within urban areas, providing pedestrians with spaces to relax, interact, and recreate.
This section has provided many lenses through which urban morphology can be analysed. Landscape ecologists, economists, transportation planners, community planners and urban planners act as an interface between the users of the urban space and the urban space itself, manifesting aesthetically and functionally attractive changes to the environment on the user’s behalf. Whereas the users govern the present of urban morphology, the planners study their behaviour to guide the environment towards a better future.
Since much of urban growth and development is forecasted and planned for, the urban fabric is dependent on technological and methodological innovation. Although scholars of urban morphology have a new generation of tools and multi-disciplinary perspectives to draw from, it is in the interest of all that the subject of urban morphology is continually developed and sharper lenses are explored.
The Urban Fabric is like an organism, boasting a life-like quality where its DNA is akin to the structural qualities so far discussed. Intrinsic to any living being is the idea of its health which ensures its continued functioning and survival. So, for a city to be healthy, its morphological traits need to be structured in such a way that encourages its continued existence. The following definition sheds light on the qualities we might use to assess a healthy urban fabric: “…the ideal city-state should be systematically and rigidly organized both in terms of its architectural layout and its social hierarchies. It should have strong public management and control to ensure order, equality and fair distribution of resources to all of its citizens.” (Singh, V., 2014, p. 1)
‘Rigid social hierarchies’ may sound like the beginnings of an Orwellian tale but, by employing the principle of charity and interpreting the definition in the best possible light we can imagine that such hierarchies would provide widespread access to education and public services. They would be governed by meritocratic advancement, where positions of leadership and responsibility are based on competence and skill rather than hereditary or nepotistic criteria. At the same time, any barriers preventing individuals from improving their social status would be minimised and incentives provided for privateers to uplift the community. This involves removing discriminatory practices and providing equal opportunities for all. There would be a focus on cultural integration where events, community centres, and public spaces cater to diverse groups, fostering a shared identity. It would be run by a transparent government where leaders and public officials should be held accountable for their actions, especially if they misuse their power or act against the interests of the citizenry. Finally, the organisation of social hierarchies would be subject to regular reviews and adjustments, ensuring that the system remains fair, just, and relevant to the changing needs of society.
What, then, might be said for the City of Crime, one that thrives on the economies of illegal trade and violence? Perhaps in Crime City, the risks are worth the rewards, allowing people from far and wide to partake and profit without any barriers to entry. Although far from being morally sound, under the definition of the ideal that this paper endorses, such a city would still count as a healthy one even if it appeared brutal and uncivilised to outsiders. The rules of urban morphology are not so stringent that they limit a healthy urban fabric to one kind of city structure. They provide a general guideline for human activity and interaction that is compatible with any kind of urban environment, no matter how foreign it may seem.
As will be described in Urbanism #2, the health of the urban fabric is in constant flux, subject to corrupting forces within and without. If urban scholars wish to bring about a future where people can live, work, play, learn, and interact with each other and their environment in meaningful ways they must not only have a grasp on a city’s morphology but also the forces that subject it to dormancy and decay.
Burgess, E. W. (1925). The growth of the city: An introduction to a research project. In R. E. Park, E. W. Burgess, & R. D. McKenzie (Eds.), The City (pp. 47-62). University of Chicago Press.
Clifton, K., Ewing, R., Knaap, G. J., & Song, Y. (2008). Quantitative analysis of urban form: a multidisciplinary review. Journal of Urbanism, 1(1), 17-45.
Garreau, J. (1991). Edge city: Life on the new frontier. Doubleday.
Levy, A. (1999). Urban morphology and the problem of the modern urban fabric: some questions for research. Urban morphology, 3(2), 79-85.
McFarlane, C. (2016). The geographies of urban density: Topology, politics and the city. Progress in Human Geography, 40(5), 629-648.
Singh, V. (2014). Relationship between Damaged Urban Fabric and Deprivation. International Journal of Scientific & Engineering Research, 5(7).
SRG Research. (2021, March 18). 2020 – The Year that Cloud Service Revenues Finally Dwarfed Enterprise Spending on Data Centers. https://www.srgresearch.com/articles/2020-the-year-that-cloud-service-revenues-finally-dwarfed-enterprise-spending-on-data-centers
Transportation Research Board. (2010). Highway Capacity Manual (5th ed.). Washington, DC: National Research Council.