What is better: a city planned from scratch or one that forms spontaneously? In popular imagination, there is a belief that if a city was planned from the beginning, it must be better or more organized than others. In practice, however, this does not guarantee a city's success.
Cities like Tamansourt in Morocco, Songdo in South Korea, and King Abdullah Economic City in Saudi Arabia serve as cautionary examples of planning a new city from scratch, only to struggle in attracting the expected number of residents. These projects involved significant investment (both operational and financial) in urban design, space, and infrastructure but overlooked the fundamental economic reasons why cities exist.
As urban planner Alain Bertaud explains, "Cities are, primarily, labor markets." This means that urban centers attract people not because of their infrastructure or spatial design alone, but due to the opportunities that emerge from population concentration. This explains, for example, why Brasília successfully attracted residents, in contrast to the planned cities mentioned above. In Brasília, as in other planned capitals, relocating the government headquarters led to a mandatory transfer of many job opportunities to the new city from its inception. This, in turn, drew people, businesses, and further residential growth. However, orchestrating job opportunities is always challenging, difficult to control or plan, and, as seen in Brasília's case, extremely costly.
Since cities exist for economic reasons that cannot be entirely controlled (in addition to being home to people with diverse needs), every city possesses some degree of spontaneity. A common misconception is the assumption that cities can be neatly categorized as either entirely planned or entirely spontaneous, as if a clear boundary existed between these two conditions. The reality is that no city is 100% planned, with every aspect of infrastructure and land use predetermined, and no city is 100% spontaneous, functioning purely on laissez-faire principles. This dualism simply does not exist.
Every City Has Planning and Spontaneity
Even in an environment that is not fully controlled, urbanization does not happen randomly. We do not typically refer to São Paulo and Rio de Janeiro as "planned cities," yet certain areas in both cities exhibit a well-organized orthogonal street grid with standardized streets and blocks, indicating some level of prior planning.
A notable example is a recently regularized condominium in Brasília. The "spontaneity" in this case was significant enough that the subdivision emerged through the occupation of public land, disregarding legal considerations. Naturally, no one would refer to this place as a "planned neighborhood." However, its spatial configuration appears orderly, featuring a hierarchical road system, an orthogonal grid, well-defined green spaces, and standardized streets and lots—all characteristics commonly associated with planned cities in the popular imagination.
These examples highlight the nuances that must be considered when classifying cities as planned or unplanned. The absence of rigid control does not necessarily result in chaotic urban layouts.
The opposite is also true. Even with planning and control, certain urban processes inevitably unfold spontaneously. All cities regarded as "planned" have, at some point, encountered issues that were not part of their initial blueprint.
Brasília, once again, exemplifies this reality. Originally designed to accommodate a maximum of 500,000 inhabitants, the city now faces persistent challenges in housing nearly 3 million residents. The limitations of its initial planning, combined with efforts to preserve Brasília's spatial configuration for its historical value, have pushed many residents away from the central areas. At the same time, a significant portion of these residents still depend on the Pilot Plan for access to jobs and services, leading to major urban mobility challenges. The city's design, despite being meticulously planned from the ground up, failed to anticipate this development.
Planning Based on Predictability
If every city possesses elements of both planning and spontaneity, and if planning from scratch does not ensure success, what is the purpose of urban planning? The short answer is: to focus on aspects where the final outcome is more predictable and permanent, since long-term planning is difficult when dealing with dynamic and unpredictable conditions.
The way buildings within city lots evolve is one of the most fluid aspects of urban management, constantly shifting based on societal needs. Large cities like New York and London are currently facing a challenge that illustrates this: the decline in demand for commercial office spaces in central areas. These well-located buildings have struggled to maintain their original function due to shifts in work dynamics, accelerated by the pandemic. Meanwhile, these same areas face high housing demand, prompting studies on how to convert these commercial spaces into residential units.
Attempting to rigidly regulate or predefine the use of private lots is impractical, as buildings must adapt to changing needs over time. The real estate market—comprising individuals and companies who buy, sell, rent, invest in, or develop properties—operates exclusively within these lots, which are the private components of the city. These spaces are in constant flux, whether due to shifting household sizes or evolving commercial activities.
The histories of cities such as New York, Barcelona, Buenos Aires, and Belo Horizonte suggest that perhaps the most critical element to plan in advance is a city's street grid and its expansion, along with the designation of areas for parks, plazas, and public amenities. These responsibilities lie solely with public authorities, and such designated spaces tend to remain stable throughout a city's lifetime. While Manhattan's buildings have changed repeatedly over the past century—whether in terms of size or function (e.g., offices being converted into housing and vice versa)—its street layout, designed more than 200 years ago, has remained largely intact. This stability is due to the fact that modifying a street grid is far more complex and expensive than altering buildings, and the function of streets and public spaces tends to endure much longer.
Therefore, the most effective approach to urban planning is first to recognize which aspects of cities are most affected by spontaneity and which are more predictable and unchanging. Typically, private spaces experience continuous evolution, while public spaces remain more consistent. Consequently, urban planning efforts should be concentrated on areas where foresight and long-term stability are achievable.
This article was originally published in Portuguese on Caos Planejado.
