From Barcelona to the world: the great lesson of Ildefons Cerdà


Engineer Ildefons Cerdà is known as the creator of Barcelona’s Eixample district. The famous urban grid is recognized and admired internationally as one of the main features of the Catalan capital. However, the Eixample is just a small part of Cerda’s greater contributions. Cerdà not only projected how Barcelona was meant to be in future, but also wrote a series of documents, in the form of general theories (such as the General Theory of Urbanization of 1867), in which he proposed what was a true revolution in modern European thought. How to plan a city? What exactly was a city? What was its origin? How had they evolved over time? And, above all, how could cities be better built? These dissertations had an underpinning raison d’être: to formulate the technical foundations for urban planning, which over time, became the basis of a universal application.

Cerdà, a strong supporter of liberal and reformist ideas, considered that the conceptualization and construction of a city was not exclusive to art. A city, though an ode to art and beauty, had to respond to a rational and fundamental objective: to serve the citizen. Thus, the city had to make life easier for the average citizen, and utilize key science and technological advances to solve common urban problems.

This is why Cerdà saw it necessary to claim that city planning was a new science, with its own method, and should be taken just a seriously as other scientific disciplines. It is not surprising, then, that Cerdà invented the word urbanization, making it a scientific and linguistic term, as he said:

“Here are the philological reasons that motivated me in my decision to adopt the word urbanization, not only to indicate any act that store to group the building and regularize its operation in the group already formed, but also the set of principles, doctrines and rules that must be applied, so that the building and its grouping […] serve to foment its development and vigor, and to increase individual well-being, the sum of which forms public happiness”[1].

Cerdà captured his objective in Barcelona’s Eixample. However, the current Eixample is quite different from what the author originally proposed. Cerdà wanted an efficient Barcelona, fast in its transport –the tramway, at that time, began to acquire importance in cities– and rich in its socio-economic relations. The administrative buildings were to be distributed equally throughout the entire extension of the new city, including: schools, markets, military buildings and even churches. And, as a good hygienist, the creation of large green spaces was proposed, both on the outskirts of the city and integrated into the urban grid. In addition, he projected some blocks (known to Barcelonians, as “mansanes” or now more commonly, “islands”) that conserve a balanced proportion of public and private space. The original blocks, in fact, represented the basic urban unit of its approach, and its regularity was understood as a true mathematical value. Each 5×5 blocks formed a neighborhood; every 2×2 neighborhoods constituted a district; and the module of 2×2 districts was considered as a sector. This urban organization allowed for a logical and rational distribution of facilities: a social center for each neighborhood; a great market for each district; and an urban park, a hospital and two government buildings for each sector.

Cerdà studied everything from Barcelona in the 19th century. He collected data on epidemics, mortality and different social classes. But he also recorded how the urban environment pollution was generated and spread out, and the need to live, as human beings, in desirable, well-ventilated and sunny spaces, with a access to of clean water and a good communication system. Barcelona, with Cerdà, had the opportunity to leave behind the dark stage of confined industrialization within its own walls in order to expand with large roads connecting it with the rest of Catalonia, Spain and Europe; the Diagonal, Meridiana and Gran Via de les Corts Catalanes, avenues to open up Barcelona to the world.

While projecting the future of Barcelona, Cerdà became one of the pioneers of modern city planning. Not in vain, international experts like Dr. Michael Neuman, professor of Sustainable Urbanism at the University of Westminster, argues that Cerdà’s opus is a universal example of a multidisciplinary work, where Engineering, Statistics, Law, Philosophy, Geography or Economics fit in [1]. Or the biologist and director of the Urban Ecology Agency of Barcelona, Salvador Rueda, who claims that the vision of Cerdà, conceived two centuries ago, can still respond to today’s global, and urban challenges. Cerdà’s legacy lives on: just last November, the CCCB, presented the first translation of his General Theory of Urbanization into English.

The distinguished urbanist has left us, as a physical and material inheritance, the Eixample and its theories. But most important is the universal value he taught us: the meaning and dignity of being a citizen of Barcelona.

[1] García-Bellido, J. (2000): “Ildefonso Cerdà y el nacimiento de la urbanística: la primera propuesta disciplinar de su estructura profunda”, Scripta Nova, 61, 1 d’abril de 2000, <>.

[2] Neuman, M. (2011): “Ildefons Cerdà and the future of spatial planning: the network urbanism of a city planning pioneer”, Town Planning Review, 82 (2), 117-144.

Albert Santasusagna Riu holds a PhD in Geography, Spatial Planning and Environmental management. Postdoctoral researcher in sustainable urbanism (AGBAR/University of Barcelona)