Urban Form

1 Urban Form

The study of urban form can reveal crucial insights into how different neighborhoods function and can help shape policies that promote a more livable and sustainable city.

In this lesson, we focus on urban form at various scales, examining the different characteristics that make up a city’s physical structure. We’ll also explore the non-physical aspects of urban form, such as density and land use, that can greatly impact the quality of life in an urban area.

Objectives

  1. Understand the different scales of urban form
  2. Explore the elements of urban form

Lectures

 

Key Takeaway:

  • Urban form refers to the size, shape, and configuration of cities. Understanding urban form at different scales and its characteristics is crucial for planning and designing sustainable urban environments.
  • Urban function, which includes society, activities, and spatial forms, plays a vital role in shaping urban form. A city’s function in relation to society, hinterland, or other settlements, the activities taking place inside of cities, and the relation between urban needs and spatial forms all impact urban form.
  • The significance of urban form and function lies in their impact on energy and environment, adapting public spaces to climate change, role of green infrastructure in adapting cities for climate change, achieving sustainable urban form, and multifunctionality of open spaces in adapting cities to climate change. It is crucial to consider the future of urban form and function in relation to climate change and urban green spaces.

 

Urban Form: Size, Shape, and Configuration

Kevin Lynch

Kevin Lynch was an American urban planner and author. He is known for his work on the perceptual form of urban environments and was an early proponent of mental mapping. His book, The Image of the City, is a classic in the field of urban planning and has been influential in shaping the way we think about cities.

In The Image of the City, Lynch argues that people form mental maps of their surroundings, and that these maps are essential for wayfinding and for understanding the city. He identifies five elements that contribute to the image of a city: paths, edges, districts, nodes, and landmarks.

  • Paths are the channels that people use to move through the city. They can be streets, sidewalks, or other transportation corridors.
  • Edges are linear features that define the boundaries of the city, such as rivers, railroads, or highways.
  • Districts are areas of the city that have a distinct character, such as a downtown business district, a residential neighborhood, or a park.
  • Nodes are points of concentration, such as intersections, public squares, or transit stations.
  • Landmarks are distinctive features, such as buildings, monuments, or natural features, that help people orient themselves in the city.

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Lynch argues that the more clearly defined these elements are, the easier it is for people to form a mental map of the city. This, in turn, makes it easier for people to get around, to understand the city, and to feel a sense of place.

 

The Image of the City has been influential in shaping the way we think about cities. It has been used by urban planners to design more legible and memorable cities. It has also been used by architects to design buildings that contribute to the overall image of the city.

The book is still relevant today, as cities continue to grow and change. As we design and build new cities, we should keep in mind the importance of creating places that are easy to understand and navigate. We should also strive to create cities that are memorable and that have a strong sense of place.

Understanding Urban Form at Different Scales

Urban form can be studied at different levels of scales, from a neighborhood to an entire city. Through this understanding of urban form at different scales, planners and policymakers can determine the appropriate materials and strategic planning to adopt for sustainable growth. At a larger scale, urban form has various indicators, including but not limited to street network configuration, density distribution patterns, building height profiles, and road sizes. At smaller scales, we should focus on human interaction with physical spaces such as parks and plazas. This understanding should also consider the role of technological advancements in shaping urban forms by infusing the built-environment with modern amenities that reflect our modern digital world.

  • Regional: This is the largest scale of urban form, and it encompasses an entire metropolitan area. A metropolitan area is a region with a large population center, as well as surrounding communities that are economically and socially linked to the center. 
    • Regions may or may not be defined by a governmental entity
  • Metropolitan Statistical Area (MSA): An MSA is a geographic area that consists of a core urban area and its surrounding urbanized areas. MSAs are defined by the Office of Management and Budget (OMB) and are used for a variety of purposes, such as economic development planning and transportation planning.
    • The Atlanta MSA is the 8th-largest in the United States and has a total population of 6.1 million.  It includes 29-counties

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  • City: A city is a large, densely populated urban area. Cities are typically centers of commerce, industry, and culture.

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Image: City of Atlanta in grey

  • District: A district is a smaller, more specialized area within a city. Districts can be defined by their function, such as a business district or a residential district, or by their history or culture, such as a historic district or a cultural district.

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Image: Map of Atlanta’s City Council Districts

  • Zip code: A zip code is a five-digit code that is used to identify a specific geographic area in the United States. Zip codes are used for a variety of purposes, such as mail delivery and marketing.

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Image: Zip code map of Atlanta

  • Neighborhood Planning Unit (NPU) – Unique to Atlanta The City of Atlanta is divided into twenty-five Neighborhood Planning Units (NPUs), which are citizen advisory councils that make recommendations to the Mayor and City Council on zoning, land use, and other planning-related matters. The NPU system was established in 1974 by the late Mayor Maynard Jackson to provide an opportunity for all residents to actively participate in the Comprehensive Development Plan, which is the official citywide vision for growth over the next five, ten, and fifteen years.

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  • Neighborhood: A neighborhood is a smaller, more intimate area within a city or town. Neighborhoods are typically characterized by a sense of community and shared identity.

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Image: Atlanta neighborhood map.  BeltLine in purple

  • Census tract: A census tract is a small, relatively permanent statistical subdivision of a county. Census tracts are used by the U.S. Census Bureau to collect data on a variety of topics, such as population, housing, and employment.

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  • Census block: A census block is the smallest unit of geography used by the U.S. Census Bureau. Census blocks are typically about 1/2 mile square.

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Elements of the Urban Form

Urban form exhibits certain characteristics that define the layout and structure of a city. These traits can be analyzed at various scales, from macro to micro-levels, and may include factors such as density, building heights, street patterns, and size and shape of blocks. The configuration of physical elements within a city, such as streetscapes, parks, public spaces or landmarks also contribute to the urban form. These characteristics give each city a unique identity and foster diverse social activities.

The characteristics of the urban form also determine how people navigate around cities by emphasizing connectivity or fragmentation between different areas. Urban planners use this knowledge to make informed decisions that balance the desired characteristics of urban form with social and environmental needs.

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  • Urban structure The overall framework of a region, town, or precinct, showing relationships between zones of built forms, land forms, natural environments, activities, and open spaces. It encompasses broader systems including transport and infrastructure networks.
  • Urban grain The balance of open space to built form and the nature and extent of subdividing an area into smaller parcels or blocks. For example, a “fine urban grain” might constitute a network of small or detailed streetscapes. It takes into consideration the hierarchy of street types, the physical linkages and movement between locations, and modes of transport.

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Image: a) Fine-grain street pattern b) Coarse-grain street pattern

  • Density + mix The intensity of development and the range of different uses (such as residential, commercial, institutional, or recreational uses).image.png
  • Height + massing The scale of buildings in relation to height and floor area and how they relate to surrounding land forms, buildings, and streets. It also incorporates the building envelope, site coverage, and solar orientation. Height and massing create the sense of openness or enclosure and affect the amenity of streets, spaces, and other buildings.

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  • Streetscape + landscape The design of public spaces such as streets, open spaces, and pathways, which includes landscaping, microclimate, shading, and planting.

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  • Façade + interface The relationship of buildings to the site, street, and neighboring buildings (alignment, setbacks, boundary treatment) and the architectural expression of their facades (projections, openings, patterns, and materials).

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Image: Urban facades in Tehran

  • Materials and Texture The close-up appearance of objects and surfaces and the selection of materials in terms of detail, craftsmanship, texture, color, durability, sustainability, and treatment. It includes public and private structures and space, street furniture, paving, lighting, and signage. It contributes to human comfort, safety, and enjoyment of the public or private domain.

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  • Public realm Much of urban design is concerned with the design and management of publicly used space and the way this is experienced and used. The public realm includes the natural and built environment used by the general public on a day-to-day basis such as streets, plazas, parks, and public infrastructure. Some aspects of privately owned space such as the bulk and scale of buildings, courtyards, and entries that are traversed by the public or gardens that are visible from the public realm can also contribute to the overall result. At times, there is a blurring of public and private realms, particularly where privately owned space is publicly used.

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  • Topography + landscape The natural environment includes the topography of landforms, water, and environment.

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Image: Ningbo Lion Mountain in China

  • Social + economic fabric The nonphysical aspects of the urban form include social factors (culture, participation, health, and well-being) as well as the productive capacity and economic productivity of a community. It incorporates aspects such as demographics and life stages, social interaction, and support networks.

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Image: Street vendors in Kuala Lumpur, Malyasia

 

Non-Physical Aspects of Urban Form, like Density

The urban form is not only about physical structures, but also encompasses non-physical aspects like density. Density refers to the number of people or activities that are present in a particular area, and it greatly influences the urban form. High-density urban areas tend to have taller and more compact buildings, whereas low-density areas have smaller and more widely spaced buildings. Urban planners must consider density alongside other factors like land values, transport options, and social needs when designing a city’s form.

In addition to physical buildings, non-physical aspects of urban form play a significant role in shaping cities. These non-physical elements can include the amount of open space available to residents, access to public transportation options, or the mix of residential and commercial properties within an area. Density is an essential component of understanding the overall functionality and attractiveness of a city as it impacts social dynamics between residents as well as environmental conditions such as air quality.

An important consideration for planners is achieving sustainable urban forms through balancing density with other features such as open spaces or green infrastructure. Multifunctional open spaces like parks offer both recreational space and opportunities for cooling during high heat waves caused by climate change. Balancing these features while taking into account environmental issues has become increasingly vital in creating healthy cities for future generations.

 

Urban Functions: Society, Activities, and Spatial Forms

 

 

Urban Morphology

Urban morphology is the study of the physical form and structure of cities.  The following image shows how urban planners think about how cities are form and how different parts connect together.  

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  • Monocentric: A monocentric city is a city that has a single center, usually a central business district (CBD). The CBD is the main focus of activity in the city, and it is where most of the jobs, businesses, and services are located. The rest of the city is often less dense and more residential in character.
  • Polycentric: A polycentric city is a city that has multiple centers. These centers may be CBDs, but they can also be other types of centers, such as university campuses, shopping malls, or industrial areas. Polycentric cities are often more decentralized than monocentric cities, and they tend to have a more balanced distribution of jobs, businesses, and services.
  • Network city: A network city is a city that is characterized by a web of interconnected transportation and communication networks. These networks allow people and goods to move easily around the city, and they help to create a sense of interconnectedness among the different parts of the city. Network cities are often more decentralized than monocentric cities, and they tend to be more economically and socially vibrant.
  • Centralized structure: A centralized structure is a type of urban morphology in which most of the city’s functions are concentrated in a central area. This central area is typically the CBD, and it is where most of the jobs, businesses, and services are located. The rest of the city is often less dense and more residential in character.
  • Decentralized structure: A decentralized structure is a type of urban morphology in which the city’s functions are spread out over a wider area. This type of structure is often found in polycentric cities, where there are multiple centers of activity. Decentralized structures can be more efficient in terms of transportation and communication, but they can also be less cohesive and less vibrant.
  • Distributed structure: A distributed structure is a type of urban morphology in which the city’s functions are distributed throughout the city. This type of structure is often found in network cities, where the transportation and communication networks allow people and goods to move easily around the city. Distributed structures can be more efficient and more equitable than centralized or decentralized structures, but they can also be more difficult to manage.
  • Hybrid structure: A hybrid structure is a type of urban morphology that combines elements of centralized, decentralized, and distributed structures. This type of structure is often found in large cities, where there is a mix of different types of neighborhoods. Hybrid structures can be more efficient, more equitable, and more vibrant than any one type of structure.

The following video demonstrates how geographers think of urban development.  The language is slightly different but it still describes urban growth.  Concentric zone model = Monocentric city; Multiple Nuclei Model = Polycentric city

Relation between Urban Needs and Urban Forms

The urban (spatial) form in a city has a direct correlation with the urban (social) needs of its residents and other stakeholders. The spatial layout of the city determines the accessibility, availability and distribution of essential services such as healthcare, education, transportation, and public amenities. Furthermore, residential areas must be able to provide adequate housing to meet the growing demand for accommodation in urban environments. In terms of infrastructure, utilities such as water supply, sewage systems and waste management need to be designed around the shape and size of the built environment.

In addition to its functional importance, urban (spatial) form is instrumental in creating social connections between communities who may share similar interests or culture. Open areas such as parks and plazas serve as important gathering points for residents to meet and interact with each other. Pedestrian-friendly streetscapes encourage walking/cycling while discouraging car usage which reduces the carbon footprint of cities.

 

 

Some Facts About Introduction to Urban Form:

  • ✅ Urban form refers to the physical characteristics of a city, including its size, shape, and configuration. 
  • ✅ The concept of urban form includes nonphysical aspects such as density. 
  • ✅ Urban functions can be conceptualized as the function of the city in relation to society, hinterland, or other settlements, or as activities taking place inside cities. 
  • ✅ Urban form and function are crucial elements in shaping cities and their sustainability. 
  • ✅ There are various factors that influence urban form, including history, culture, transportation, and economy. 

FAQs about Introduction To Urban Form

What is urban form?

Urban form refers to the physical characteristics of a city, including its size, shape, and configuration. It encompasses both the physical features of a city, such as building materials, facades, and fenestration, and nonphysical aspects such as density.

What factors determine the urban form of a city?

The urban form of a city is determined by a range of factors, including historical and cultural influences, economic and political forces, and geographic and environmental conditions. Some specific factors that can shape urban form include housing type, street type, and spatial arrangement.

What is the relationship between urban form and urban function?

Urban form and urban function are closely related, with the physical structure of a city playing a crucial role in determining the types of activities and functions that take place within it. Urban function can be conceptualized as either a function of the city in relation to society, hinterland, or other settlements, or as a relation between urban needs and urban forms.

How does urban form impact energy use and the environment?

The urban form of a city has a significant impact on energy use and the environment, with factors such as building materials, density, and street layout playing a crucial role. Research has shown that compact, mixed-use urban forms with good access to public transportation can help reduce energy consumption and greenhouse gas emissions.

What are some examples of urban patterns that can be identified at different scales?

Urban patterns can be identified at a range of scales, from the building level to the scale of the city as a whole. At the building level, patterns can include the use of specific building materials or façade styles. At the city scale, patterns can include the layout and organization of streets, the density and arrangement of buildings, and the overall shape of the city.

 

Quick Check

What scale of urban form is unique to Atlanta?

Neighborhood Planning Unit

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City Council District

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Network City

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ZIP Code

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Check Answer

 

 

 

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