Here’s how developing world cities can plan for the next half century of rapid urban growth

Can Tho, Vietnam, 2017. Image: Getty.

 Cities continue to grow at a rapid rate. Within the 100 Resilient Cities Network, more than half of the cities in Latin America, Asia, the Middle East, and Africa are seeing their population expand by 2 per cent or more annually – the benchmark of rapid urban growth.

A metropolis like Lagos, Nigeria demonstrates how drastic this can be: increasing from 7.1m to 9.8m residents between 2000 and 2015, its population is expected to more than triple to 34m by 2050.

To begin to understand what this means for urban resilience, 100RC has collaborated with New York University’s Marron Institute to develop urban growth projections for 20of our most rapidly expanding cities located in the Global South.

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A growing population may increase density in central areas, but it also has the effect of dramatically expanding a city’s physical boundaries. Population density in cities is, on average, declining by 2 per cent per year, and almost every city globally is experiencing significant spatial expansion as a result – including some that have no population growth, and even a few that are losing population.

Nairobi, Kenya, for example, is forecast to increase its total area 5.3-fold by 2050; in that same time frame, the twenty cities in this study will on average increase their total area 3.7-fold.

As these cities continue growing outward, a significant amount of work must be undertaken to not only provide for projected expansion but also to guide its development. Almost all of the infrastructure that will have to accommodate this growth has yet to be built, presenting a significant opportunity to plan for expansion in an efficient and equitable manner that contributes to the city’s overall resilience.


To be truly impactful, a city Resilience Strategy must not only consider existing urban areas but also account for projected urban growth and use it as an opportunity to accelerate resilience-building. Failure to plan and organise the expansion areas of cities is the root cause of a number of serious resilience challenges: housing affordability, traffic congestion, poor access to labour markets and public space, natural hazard risk to communities, loss of natural environment and ecosystems, and lack of basic services such as water, sanitation, and electricity. 

It also costs more. The expense of bringing critical infrastructure into existing communities is 3 to 9 times higher than the cost of installing the basic trunk infrastructure in planned communities, incrementally, in advance of development.

Satellite imagery at three discrete points in time (1990, 2000, and 2014) has been used to assess the quantity and quality of the urban growth in this period and to support the development of urban growth projections through 2050. Here we present a handful of key indicators that the Marron Institute uses to characterise the quality of urban growth, each of which has particular implications for urban resilience: average city block size, street width, proximity of residential areas to arterial roads, and percentage of open space available for residents.

Quantifying urban expansion

As cities grow, they must also contend with administrative and geographic boundaries. Once an urban centre expands beyond a single jurisdiction, the resulting regional fragmentation adds extra complexity to city governance and must be factored into planning processes.

This challenge is currently being confronted by several metropolitan areas within the 100RC Network. For example, the UK city of Manchester and its surrounding boroughs came together in 2010 as the Greater Manchester Combined Authority, thereby giving more planning autonomy to the metropolitan region, rather than each council independently planning for a system that affects the metropolitan area as a whole.

While most of Byblos’ urban region falls within its municipal boundary, Buenos Aires’s urban region mostly falls outside of city jurisdiction.

Da Nang, Vietnam, has the highest urban growth rate within the 100RC network; the metro area expanded by 5.6 per cent annually between 2000 and 2014.

Most of its recent growth extended well beyond the city’s administrative boundaries and into adjoining areas. This poses challenges for integrated spatial planning and may call for more active regional planning to compensate for the resulting fragmentation, as described above.

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The shape of a city as it grows also has implications for urban resilience planning. The image above demonstrates that, over the years, Can Tho has elongated and become less dense. This has significant impacts on transportation within the urbanised area, where the average commuting time to the city centre becomes higher than in more circular cities and where greater difficulties arise in managing an extended system. Already existing environmental challenges caused by pollution are additionally exacerbated, meaning that urban form holds a direct impact on a city’s chronic stresses.

Streets and walkability

Multimodal streets are a unique characteristic of urban areas. Four-way intersections in particular improve accessibility not only for drivers, but also for pedestrians and cyclists. They minimise trip distance for greater walkability and cycling as well as increase route options, which in turn can decrease congestion and vehicular traffic.

A lower share of four-way intersections reduces the route choice within a given area, increasing the changes of congestion and impeding walkability. Edited for clarity, these satellite images demonstrate that Santa Fe, Argentina has a higher percentage of these intersections (46 per cent) than does Byblos, Lebanon (6 per cent).

The average size of a city block also affects how accessible a neighbourhood is. Residential blocks that measure more than 4 to 5 hectares begin to impede walkability, by increasing the distance between points.

In Cali, Colombia, for example, the city’s older area is easier to navigate on foot than its newly-developed districts. A city’s level of walkability is important for promoting public health objectives, cohesive and engaged communities, and a number of other urban resilience benefits.

Average city block size in Can Tho, Vietnam far exceeds that of Cali, Colombia, implying that the latter’s neighbourhoods are more accessible to pedestrians.

Arterial roads

When planned effectively, arterial roads support urban resilience by linking residents to jobs, providing vulnerable and underserved communities access to basic services like water and power, and allowing for generally greater mobility around a city. Arterial roads carry public transportation and trunk infrastructure such as water supply, power and telecommunications and, as a public good, must be planned and implemented through government action. They are far more cost-effective and efficient to provide if created in anticipation of settlement, before development occurs in that area.

Ideally, every resident would live within walking distance of a road that can efficiently carry public transportation – even if that system is not yet in place. For this reason, the Marron Institute has studied the proximity of built-up areas to arterial roads as a key metric in the quality of urban expansion; it has additionally developed the Making Room methodology of planning a grid of arterial roads in areas of projected urban expansion and working with local government to secure rights of way to these corridors in advance of development.

Addis Ababa exhibits a shortage of wide arterial roads in the area developed between 1986 and 2017. Prior to 1986, the city exceeded global and regional norms, but it is now statistically similar to those values, and the share of land with access to this type of road has declined by 26 percentage points.

Projections

Based on overall global trends, the cities in the study are expected to continue their outward expansion, declining in urban density at an annual rate of 1-2 per cent, while increasing their land consumption in some cases up to 7-fold by 2050.

The graphic below organizes the participating cities by their expected population growth rates, and shows their projected growth in area over the next 35 years. In that timeframe, Can Tho, the fastest-growing city from 2000-10, is expected to experience population growth of 114 per cent and add as much as 26,000ha to its territory, representing a 5-fold increase in total area. Medellin, on the other hand, is on a path toward a 40 per cent increase in population and add as much as 43,600ha, or a 1.6-fold increase in total area.

Click to expand. Cities are organised from left to right, top to bottom, by their expected percent increase in total area by 2050, given a 2 per cent decline in population density.

Next steps

The 20 cities in the NYU study are currently working to incorporate these findings into their Resilience Strategy development and implementation. We hope the findings will influence existing project development and lead to new initiatives focused on planning in advance for urban growth in a way that supports the broader resilience of cities.

Rebecca Laberenne is associate director, innovation in the built environment, City Solutions at 100 Resilient Cities. Patrick Lamson-Hall is research scholar at NYU Stern Urbanization Project.

This article previously appeared on the 100 Resilient Cities blog.

 
 
 
 

A new wave of remote workers could bring lasting change to pricey rental markets

There’s a wide world of speculation about the long-lasting changes to real estate caused by the coronavirus. (Valery Hache/AFP via Getty Images)

When the coronavirus spread around the world this spring, government-issued stay-at-home orders essentially forced a global social experiment on remote work.

Perhaps not surprisingly, people who are able to work from home generally like doing so. A recent survey from iOmetrics and Global Workplace Analytics on the work-from-home experience found that 68% of the 2,865 responses said they were “very successful working from home”, 76% want to continue working from home at least one day a week, and 16% don’t want to return to the office at all.

It’s not just employees who’ve gained this appreciation for remote work – several companies are acknowledging benefits from it as well. On 11 June, the workplace chat company Slack joined the growing number of companies that will allow employees to work from home even after the pandemic. “Most employees will have the option to work remotely on a permanent basis if they choose,” Slack said in a public statement, “and we will begin to increasingly hire employees who are permanently remote.”

This type of declaration has been echoing through workspaces since Twitter made its announcement on 12 May, particularly in the tech sector. Since then, companies including Coinbase, Square, Shopify, and Upwork have taken the same steps.


Remote work is much more accessible to white and higher-wage workers in tech, finance, and business services sectors, according to the Economic Policy Institute, and the concentration of these jobs in some major cities has contributed to ballooning housing costs in those markets. Much of the workforce that can work remotely is also more able to afford moving than those on lower incomes working in the hospitality or retail sectors. If they choose not to report back to HQ in San Francisco or New York City, for example, that could potentially have an effect on the white-hot rental and real estate markets in those and other cities.

Data from Zumper, an online apartment rental platform, suggests that some of the priciest rental markets in the US have already started to soften. In June, rent prices for San Francisco’s one- and two-bedroom apartments dropped more than 9% compared to one year before, according to the company’s monthly rent report. The figures were similar in nearby Silicon Valley hotspots of San Jose, Mountain View, Palo Alto.

Six of the 10 highest-rent cities in the US posted year-over-year declines, including New York City, Los Angeles, and Seattle. At the same time, rents increased in some cheaper cities that aren’t far from expensive ones: “In our top markets, while Boston and San Francisco rents were on the decline, Providence and Sacramento prices were both up around 5% last month,” Zumper reports.

In San Francisco, some property owners have begun offering a month or more of free rent to attract new tenants, KQED reports, and an April survey from the San Francisco Apartment Association showed 16% of rental housing providers had residents break a lease or unexpectedly give a 30-day notice to vacate.

It’s still too early to say how much of this movement can be attributed to remote work, layoffs or pay cuts, but some who see this time as an opportunity to move are taking it.

Jay Streets, who owns a two-unit house in San Francisco, says he recently had tenants give notice and move to Kentucky this spring.

“He worked for Google, she worked for another tech company,” Streets says. “When Covid happened, they were on vacation in Palm Springs and they didn’t come back.”

The couple kept the lease on their $4,500 two-bedroom apartment until Google announced its employees would be working from home for the rest of the year, at which point they officially moved out. “They couldn’t justify paying rent on an apartment they didn’t need,” Streets says.

When he re-listed the apartment in May for the same price, the requests poured in. “Overwhelmingly, everyone that came to look at it were all in the situation where they were now working from home,” he says. “They were all in one-bedrooms and they all wanted an extra bedroom because they were all working from home.”

In early June, Yessika Patapoff and her husband moved from San Francisco’s Lower Haight neighbourhood to Tiburon, a charming town north of the city. Patapoff is an attorney who’s been unemployed since before Covid-19 hit, and her husband is working from home. She says her husband’s employer has been flexible about working from home, but it is not currently a permanent situation. While they’re paying a similar price for housing, they now have more space, and no plans to move back.

“My husband and I were already growing tired of the city before Covid,” Patapoff says.

Similar stories emerged in the UK, where real estate markets almost completely stopped for 50 days during lockdown, causing a rush of demand when it reopened. “Enquiry activity has been extraordinary,” Damian Gray, head of Knight Frank’s Oxford office told World Property Journal. “I've never been contacted by so many people that want to live outside London."

Several estate agencies in London have reported a rush for properties since the market opened back up, particularly for more spacious properties with outdoor space. However, Mansion Global noted this is likely due to pent up demand from 50 days of almost complete real estate shutdown, so it’s hard to tell whether that trend will continue.

There’s a wide world of speculation about the long-lasting changes to real estate caused by the coronavirus, but many industry experts say there will indeed be change.

In May, The New York Times reported that three of New York City’s largest commercial tenants — Barclays, JP Morgan Chase and Morgan Stanley — have hinted that many of their employees likely won’t be returning to the office at the level they were pre-Covid.

Until workers are able to safely return to offices, it’s impossible to tell exactly how much office space will stay vacant post-pandemic. On one hand, businesses could require more space to account for physical distancing; on the other hand, they could embrace remote working permanently, or find some middle ground that brings fewer people into the office on a daily basis.

“It’s tough to say anything to the office market because most people are not back working in their office yet,” says Robert Knakal, chairman of JLL Capital Markets. “There will be changes in the office market and there will likely be changes in the residential market as well in terms of how buildings are maintained, constructed, [and] designed.”

Those who do return to the office may find a reversal of recent design trends that favoured open, airy layouts with desks clustered tightly together. “The space per employee likely to go up would counterbalance the folks who are no longer coming into the office,” Knakal says.

There has been some discussion of using newly vacant office space for residential needs, and while that’s appealing to housing advocates in cities that sorely need more housing, Bill Rudin, CEO of Rudin Management Company, recently told Spectrum News that the conversion process may be too difficult to be practical.

"I don’t know the amount of buildings out there that could be adapted," he said. "It’s very complicated and expensive.

While there’s been tumult in San Francisco’s rental scene, housing developers appear to still be moving forward with their plans, says Dan Sider, director of executive programs at the SF Planning Department.

“Despite the doom and gloom that we all read about daily, our office continues to see interest from the development community – particularly larger, more established developers – in both moving ahead with existing applications and in submitting new applications for large projects,” he says.

How demand for those projects might change and what it might do to improve affordable housing is still unknown, though “demand will recover,” Sider predicts.

Johanna Flashman is a freelance writer based in Oakland, California.