The 21 Laws of Cities
In our obsession with cities, especially how we build them to become more sustainable and equitable for the growing urban population, Reza and I have read and reviewed dozens of the most important research, books and analysis of this fascinating organism. Off the back of these reviews we’ve extracted 20 laws of Cities.
20 laws that offer we (citizens and residents) a template for what we have to bear in mind as we build the future.
We’ve digested work from thinkers and practitioners including Geoffrey West and Jane Goodall. We’ve borrowed ideas from Luis Bettencourt, Richard Florida and Donella Meadows. We’ve pondered the thinking of Nicola Dempsey and Edward Glaeser/Hedi Kallal. We’ve wrapped all these ideas in our own perspective having worked in utilities (power and water), renewables, construction and cities for the last couple decades of our careers.
Based on all these, here are the 20 Laws of (Thriving and Sustainable) Cities. These laws are interrelated and connected. We are talking about systems and, consequently, no one law stands above the others but they work together to ensure that the best cities are built for the people.
On to Law #1.
Urban Scaling Predicts City Performance: This law posits that as cities grow, they exhibit predictable scaling relationships across socioeconomic and infrastructural indicators. The research backing up this law is from the work of Geoffrey West and Bettencourt et al. (2007) where they demonstrated that various urban indicators scale with population size, following power laws. A power law is a type of relationship where one thing changes by a fixed factor whenever another thing changes by a certain amount, often seen in situations where big events or values are much less common than smaller ones, like how there are a few very tall mountains but many more small hills. In city terms, a few cities are really big with lots of people and there are many more smaller towns with fewer people that following some mathematical relationships. Failing to account for the scaling (power) law in city planning or decision making can lead to inefficient resource allocation and missed opportunities for economic growth. New York City has leveraged its size to become a global hub of innovation and economic activity, with patents and GDP growing superlinearly with population, as can be predicted by urban scaling laws (Bettencourt et al., 2007).
Urban Density Drives Efficiency: This law simply suggests that higher urban density, when thoughtfully planned, can lead to more efficient use of resources, reduced carbon emissions, and improved quality of life in a city. This law is based on work by Newman and Kenworthy (1989) ‘Gasoline consumption and Cities Revisited (What Have We Learnt?) where the authors established the relationship between urban density and energy consumption. The inefficiencies we see as a result of urban sprawl in many suburbs of the US is the best example of the flouting of this law. Low-density urban sprawl results in increased infrastructure costs, higher energy consumption, and greater environmental impact. As shown in the research, the city of Atlanta, USA, with its low-density sprawl, consumes significantly more energy per capita than denser cities like Barcelona, Spain, despite having similar populations (Newman and Kenworthy, 1999).
Urban Innovation Drives Progress: This law will not come as a surprise to anyone who’s studied how the economic powerhouses of most countries are their biggest cities. Cities are hubs of innovation, with larger cities generating disproportionately more patents, startups, and creative output. This led to the work of Richard Florida (2002), in his book ‘The Rise of the Creative Class’, where he highlighted the role of the "creative class" in driving urban innovation and economic growth. While we are not advocates for growth at all costs, it is evident that cities that fail to foster innovation (and it doesn’t always have to be technical innovation) experience economic stagnation and reduced competitiveness in the global economy. But unbridled growth also increases inequality. San Francisco's Bay Area has cultivated a robust innovation ecosystem, leading to it becoming a global tech hub and driving significant economic growth (Florida, 2019). But it also has some of the highest rates of homelessness in the country with 47/10,000 people homeless (the average for US cities is 19/10,000 people).
Regional Cooperation Enhances Sustainability and Growth: Sustainable cities cannot exist in isolation; cities must coordinate with surrounding municipalities and rural areas for truly sustainable regional development. Access to food, water and the basic resources for thriving cities can only come from engaging cooperatively with locational neighbors. Stephen Wheeler in ‘Planning for Metropolitan Sustainability” (2000) argued for the importance of regional approaches to urban sustainability. A lack of regional cooperation can lead to inefficient resource use, conflicting land-use policies, and inability to address cross-boundary environmental issues or even worse scarcity in some cities. There are good examples of regional cooperation like in the Greater Copenhagen region in Denmark and Sweden which has implemented cross-border cooperation on transportation, labor market, and environmental issues, leading to more integrated and sustainable regional development (OECD, 2009).
Mixed Land Use Enhances Urban Vitality: Cities with a mix of residential, commercial, and recreational land uses tend to be more vibrant, walkable, and economically resilient. And we are not talking about just mixed use buildings here. This law is based on pivotal work by Jane Jacobs (1961) where she highlighted the importance of mixed-use neighborhoods for urban vitality. So what are mixed land use areas? Mixed land use areas are urban neighborhoods that combine diverse functions such as residential, commercial, industrial, and civic uses in close proximity, promoting vibrant street life and economic vitality. In her seminal work "The Death and Life of Great American Cities” Jacobs highlighted that strict zoning laws that prevent mixed-usage in neighborhoods (and leading to single-use areas) can result in car dependency, reduced social interaction, and economic vulnerability. This is evident especially in our cities with the most vulnerable populations. Portland, Oregon, has embraced mixed-use development, leading to vibrant neighborhoods like the Pearl District, which has transformed from an industrial area to a thriving mixed-use community (City of Portland, 2021).
Social Equity Underpins Urban Sustainability: Considering the amount of inequality we see in our modern cities, this sixth law is one that we believe has been grossly neglected in the city planning. It cannot be overstated that equitable access to resources, opportunities, and services across all neighborhoods and demographics is fundamental to creating sustainable and inclusive cities. Nicola Dempsey et al. in “The Social Dimension of Sustainable Development: Defining Urban Social Sustainability" (2011) identified social equity as a key dimension of urban social sustainability. Neglecting social equity can lead to (and is already leading to) increased segregation, social unrest, and overall decreased quality of life for many city residents. And it’s not just the less-resourced city dwellers that suffer. The impact is felt by all. Copenhagen, Denmark, has prioritized social equity through policies like mixed-income housing and universal access to high-quality public services, resulting in consistently high rankings in quality of life and social mobility indices (OECD, 2016 and Monocle 2024). While it leads to stagnation, as the socialist undertones of this law might suggest, we emphasize that the goal is to not implement this law in isolation. This applies here, as it can be implemented with Laws 1 and 2 above in mind, as it applies to all the laws when implemented without due consideration.
Affordable Housing Ensures Social Equity: This law goes hand in hand with Law #3 (Urban Innovation Drives Progress). Ensuring an adequate supply of affordable housing across all urban areas is crucial for social equity, economic diversity, and sustainable growth. The growth myst go hand-in-hand with affordability for the residents of the city. In “ Urban Form and Social Sustainability: The Role of Density and Housing Type” Glenn Bramley and Sinead Power (2009) identified affordable housing as a key component of urban social sustainability. Lack of affordable housing can lead to gentrification, displacement of low-income residents, and increased homelessness.. Vienna, Austria, has a long-standing commitment to social housing, with about 60% of residents living in subsidized housing, resulting in high levels of social integration and low levels of segregation (Hatz et al., 2016) and even more recently, as reported by Monocle, these homes are great for social cohesion. Which ties to the next law…
Public Spaces Foster Social Cohesion: As the Author of ‘Bowling Alone’ Robert Putnam and the US Surgeon General have shared, we are dealing with issues of social fracturing and loneliness. Some of this can be attributed to the flouting of Law #8 in our cities. Accessible, well-designed public spaces are essential for fostering community interactions, civic engagement, and social cohesion in cities. The increase in social cohesion will help reduce the loneliness we are currently feeling as a society. Whyte (1980) demonstrated the importance of public space design in his study "The Social Life of Small Urban Spaces” and the lack of quality public spaces has led to reduced social interaction, decreased sense of community, and potential increases in crime. We no longer gather like we used to or join groups that can enhance our individual well-being. We do not encourage free public spaces that can foster that. But some cities are choosing to fight back. For example: Medellín, Colombia, has invested heavily in public spaces and libraries in low-income areas, contributing to significant reductions in crime rates and improvements in social cohesion (Drummond et al., 2012). It’s why your techie friends have been relocating to Medellin, it is much safer and socially cohesive than it used to be.
Social Infrastructure is as Crucial as Physical Infrastructure: This law ties closely to Law #8. Investment in social infrastructure - including schools, libraries, community centers, and healthcare facilities - is as important as physical infrastructure for sustainable urban development. In "Palaces for the People." Klinenberg argues that strong social infrastructure increases the resilience of urban communities to stresses (social and environmental), foster social connections and can reduce inequality in our cities. This once again is a law that has to be closely implemented along with several others of the 20 Laws. To neglect social infrastructure leads to reduced quality of life, decreased community resilience, and increased social isolation. Bogotá, Colombia's network of public libraries, particularly in low-income areas, has significantly improved educational outcomes and social cohesion according to research by Montoya (2014).
Urban Greening Enhances Resilience: “Green space exposure on depression and anxiety outcomes: A meta-analysis” from 2017 shows that Increasing green spaces and urban vegetation improves environmental quality, residents' well-being, and cities' resilience to climate change. Simply; the loss of green spaces in cities can lead to mental health deficiencies. Wolch et al. (2014) reviewed the multiple benefits of urban greening for sustainability and public health. In more practical and physical terms the lack of urban green space can exacerbate urban heat island effects, reduce biodiversity, and negatively impact residents' mental and physical health.The positive effects are clear when action is taken towards implementing this law and Singapore's "City in a Garden" approach has increased green cover from 36% in 1986 to 47% in 2016, despite rapid urbanization, improving air quality and livability (National Parks Board, Singapore, 2020).
Sustainable Transportation Improves Livability: Multimodal forms of transportation ensure the liability of a city for all residents at all income levels. Prioritizing public transit (buses and trains), walking, and cycling over private car use leads to more sustainable, livable, and equitable cities. Cervero's book "The Transit Metropolis" (1998), discusses how compact, transit-oriented development can shorten trips, encourage non-motorized travel, and reduce per capita fuel consumption. A obviously more sustainable approach to thriving cities. The typical American approach, car-centric planning, can result in increased pollution, traffic congestion, and reduced accessibility for non-drivers. The perfect positive example of the implementation of this law is Amsterdam's focus on cycling infrastructure, which has resulted in 32% of all trips in the city being made by bicycle, reducing congestion and improving air quality (we’ll ignore the pervasive weed smell).
Local Economic Development Builds Resilience: Jane Jacobs, referenced in Law #5 above, preached about fostering diverse, locally-rooted economies as a way to enhance urban resilience and provide more equitable economic opportunities for residents. And by all residents, we mean all residents. She emphasized the importance of diverse local economies for urban vitality in "The Economy of Cities" with the key consideration here being the need for resilience. There should be a vibrant economy made up of diverse types and sizes of businesses. Over-reliance on a few large employers or sectors can make cities vulnerable to economic shocks and limit opportunities for small businesses and entrepreneurs. Cleveland, Ohio's Evergreen Cooperatives initiative has created worker-owned businesses in low-income neighborhoods, providing stable jobs and building community wealth. This model has also been replicated in downtown Detroit.
Participatory Governance Leads to Better Outcomes: Sherry Arnstein's (1969) “Ladder of Citizen Participation" highlighted the importance of meaningful citizen involvement in urban planning.Inclusive decision-making processes that actively involve diverse community members lead to more equitable and effective urban policies. The city of Porto Alegre, Brazil pioneered participatory budgeting, allowing citizens to directly influence municipal spending priorities, leading to improved public services and increased civic engagement (Baiocchi, 2005). And a consequence of not doing this, and focusing on top-down decision-making, can result in policies that don't address community needs and can lead to lack of public support for urban initiatives. The increased transparency and citizen empowerment leads to improved services for the residents. Cities like New York, Paris and Madrid (with Decide Madrid) have all borrowed the Porto Alegra approach and are seeing success.
Cultural Preservation Strengthens Community Identity: When you visit main historic cities in the world there is a certain ‘energy’ or ‘nuance’ in these cities that are unique to them. This is what you get when you preserve the cultural heritage of the city even as it grows and modernizes. Preserving and celebrating cultural heritage and diversity clearly strengthens city identity and social cohesion. UNESCO (2016) recognizes culture as a key driver of sustainable urban development in its report "Culture: Urban Future.”. Neglecting cultural preservation leads to loss of local identity, reduced social cohesion, and decreased tourism potential. A city that has preserved its culture is Fez, Morocco. The city has successfully preserved its historic medina, maintaining cultural traditions while also supporting local economies and tourism (UNESCO, 2021).
Digital Inclusion Ensures Equal Opportunities: One of the musts to ensure thriving residents in cities is the need for digital inclusion. Especially in our increasingly digital world of AI. Equitable access to digital infrastructure and skills is essential for full participation in modern urban life and, if we want to address inequality, we have address digital inclusion head-on. Caragliu et al. (2011) emphasized the importance of digital inclusion in their work on smart cities. In the paper ‘Smart Cities in Europe’ the authors define a smart city as one that invests in human and social capital, traditional and modern communication infrastructure, and sustainable economic development to enhance the quality of life and management of natural resources through participatory governance. It is not just about technology but it requires participation in the technologies that ensure thriving in the 21st century. Digital exclusion can exacerbate existing inequalities, limiting access to education, job opportunities, and public services. Seoul, South Korea (in Songdo) has implemented comprehensive digital inclusion policies, including free Wi-Fi across the city and digital literacy programs, leading to high levels of internet access and digital participation (Seoul Metropolitan Government, 2020).
Climate Resilience is an Urban Imperative: Whether you accept it or note, something is changing with our climate. I was recently in Chicago and, in a first in our lifetime event, downtown Chicago got hit with a tornado. Cities must adapt to climate change impacts while simultaneously working to mitigate their contributions to global warming. The greatest cities in the world are ecologically dependent on water bodies and we experience the worst effects of climate change through these water bodies; drought, flooding and contamination. Rosenzweig et al. (2010) highlighted the crucial role of cities in climate change adaptation and mitigation. Failure to address climate resilience is leaving cities vulnerable to extreme weather events, sea-level rise, and other climate-related risks. The city of Rotterdam, Netherlands has implemented a comprehensive climate adaptation strategy, including water plazas that serve as recreational spaces in dry weather and water storage during heavy rainfall (City of Rotterdam, 2019). More cities will have to adopt this.
Urban Form Shapes Social Interactions: There is that intangible but tangible feeling one gets in a city that has a welcoming ‘form’. The physical layout and design of cities significantly influence social interactions, community formation, and quality of life. Jan Gehl (2010) demonstrated how urban design impacts social life in his book "Cities for People." He posits that human behaviors and interactions, and the understanding of those behaviors should be factored into how cities are designed and laid out. The idea being that poor urban design can lead to social isolation, reduced community cohesion, and decreased quality of life. Curitiba, Brazil's integrated urban planning approach, including linear transit-oriented development, has fostered vibrant, mixed-use corridors that promote social interaction and sustainable mobility (Macedo, 2013).
Urban Metabolism Requires Circular Thinking: The city of Amsterdam has adopted a circular economy strategy, aiming to become fully circular by 2050, with initiatives like recycling building materials and promoting sharing economies (City of Amsterdam, 2020) inn recognition of the fact that cities are organic. And cities should be viewed as metabolic systems, with flows of resources, energy, and waste. It is always flow. Adopting circular economy principles can help optimize these flows. Kennedy et al. (2007) applied the concept of metabolism to urban systems. In “The study of urban metabolism and its applications to urban planning and design” the researchers emphasized the need for circular resource flows which are counter to the linear "take-make-dispose" models that we’ve adopted and have led to resource depletion, increased waste, and environmental degradation.
Urban Food Systems Impact Sustainability: As more and more people in cities yearn for more organically grown and sustainable food products this rule will become ever more prominent in the future. The way cities produce, distribute, consume, and dispose of food has significant implications for sustainability. It is why we are seeing more vertical farms and community farms in city plots. Pothukuchi and Kaufman (1999) highlighted the importance of food systems in urban planning and sustainability. Even though the research is close to 25 years ago from the writing of these laws, we are going to have to refashion our cities to reflect this need. The consequence here is that Inefficient urban food systems can lead to increased food insecurity, higher carbon emissions, and increased waste. Toronto, Canada has implemented a comprehensive food strategy, including urban agriculture initiatives and improved food distribution systems, leading to increased food security and reduced environmental impact (Toronto Food Policy Council, 2018).
Urban Health is a Collective Responsibility: A theme that runs through these laws is the need for is to ensure that there is collaboration and cooperation across the board. The health of urban populations is influenced by a complex interplay of social, environmental, and economic factors. The other laws highlight this and a consequence is that, according to Marmot et al. (2008) "Closing the gap in a generation: health equity through action on the social determinants of health” the social determinants of health in urban contexts. Neglecting the broader determinants of health can lead to increased health inequalities and overall poorer health outcomes. The Healthy Cities initiatives in Europe, pioneered by the WHO, have led to cities like Ljubljana, Slovenia implementing comprehensive health-promoting policies across multiple sectors, resulting in improved health outcomes and quality of life (WHO, 2018).
So these are the 20 Laws. The imperative here is that we must factor all these laws into how we build our cities going forward. The major blights on our societies that we are currently experiencing - loneliness, depression, pandemics, growing inequality, decaying infrastructure, climate change effects, lack of resources - are all symptoms of the breakdown of one or more of these laws. And the quicker we start to think about these problems systematically, the closer we will get to building the cities for the people.
References
"Growth, innovation, scaling, and the pace of life in cities" by Luís M. A. Bettencourt, José Lobo, Dirk Helbing, Christian Kühnert, and Geoffrey B. West (2007)
"The social dimension of sustainable development: Defining urban social sustainability" by Nicola Dempsey, Glen Bramley, Sinéad Power, and Caroline Brown (2011)
"Gasoline consumption and cities: A comparison of U.S. cities with a global survey" by Peter W. G. Newman and Jeffrey R. Kenworthy (1989)
"The Death and Life of Great American Cities" by Jane Jacobs (1961)
"The Social Life of Small Urban Spaces" by William H. Whyte (1980)
"The Transit Metropolis: A Global Inquiry" by Robert Cervero (1998)
"Urban green space, public health, and environmental justice: The challenge of making cities 'just green enough'" by Jennifer R. Wolch, Jason Byrne, and Joshua P. Newell (2014)
"Social sustainability: a catchword between political pragmatism and social theory" by Glen Bramley, Nicola Dempsey, Sinéad Power, Caroline Brown, and David Watkins (2009)
"The Economy of Cities" by Jane Jacobs (1969)
"A Ladder of Citizen Participation" by Sherry R. Arnstein (1969)
"Culture: Urban Future; Global Report on Culture for Sustainable Urban Development" by UNESCO (2016)
"Smart Cities in Europe" by Andrea Caragliu, Chiara Del Bo, and Peter Nijkamp (2011)
"Climate Change and Cities: First Assessment Report of the Urban Climate Change Research Network" edited by Cynthia Rosenzweig, William D. Solecki, Stephen A. Hammer, and Shagun Mehrotra (2010)
"Palaces for the People: How Social Infrastructure Can Help Fight Inequality, Polarization, and the Decline of Civic Life" by Eric Klinenberg (2018)
"Planning for Metropolitan Sustainability" by Stephen M. Wheeler (2002)
"The Rise of the Creative Class" by Richard Florida (2002)
"Cities for People" by Jan Gehl (2010)
"The changing metabolism of cities" by Christopher Kennedy, John Cuddihy, and Joshua Engel-Yan (2007)
"Community food security: A framework for planning and action" by Kameshwari Pothukuchi and Jerome L. Kaufman (1999)
"Closing the gap in a generation: health equity through action on the social determinants of health" by Michael Marmot, Sharon Friel, Ruth Bell, Tanja AJ Houweling, and Sebastian Taylor (2008)
“Urban Form and Social Sustainability: The Role of Density and Housing Type” Glenn Bramley and Sinead Power
“Green space exposure on depression and anxiety outcomes: A meta-analysis” Ziquan Liu et al