Don't Miss >

Understanding the History of Slums – Alejandro De Castro Mazarro, Columbia University

By on October 5, 2016
Lecturer - profile

Alejandro De Castro Mazarro

Adjunct Assistant Professor

Main affiliation
Columbia University


United States

North America



Alejandro De Castro Mazarro is an Adjunct Assistant Professor in the Urban Planning program at Columbia GSAPP and a partner of the architecture office BuroA. At GSAPP, he coordinated the Latin Lab research group from 2010 to 2016, and teaches seminars and studios. In addition to GSAPP, he has taught at Harvard University, the Pratt Institute, the Technical University Darmstadt, the Institute of Urbanism of Grenoble, the International University of Catalunya in Barcelona, and Escola de Cidade (São Paulo).

Alejandro’s work explores the rhetoric dimension of planning and architecture arguments delving with marginalized communities, to propose spatial practices that are sensitive to both form and policy. As a professional architect he has developed these ideas at the design of urban upgrading projects and at competition awarded projects for social infrastructure in public schools in Spain. In parallel, Alejandro has co-edited with Francisco Diaz the book “Who Cares of Chilean Cities” (ARQ and GSAPP Books), which investigates the problematic relationship between social actors and the production of public space in contemporary Chile. His research has been presented at conferences in San Juan (Puerto Rico), Rio de Janeiro, Singapore, Hong Kong, Morelia (Mexico) and Cambridge (United Kingdom); published at Elsevier’s encyclopedia “House and Home”; and exhibited at the Guggenheim Museum “Participatory City: 100 Urban Trends” show in New York.

Alejandro Castro Mazarro received his degree in Architecture from the University of Seville (Spain), a Master of Science in Advanced Architectural Design from Columbia University in New York, and a Phd in Architecture from the University of Alcala in Madrid.

English Proficiency

Previous experience of recording video lectures

Experience of lecturing to large audiences

Experience of lecturing to large audiences

Frequency of lectures

Recording opportunities
Habitat III attendance and availability
17 to 19 October



Main themes
Sustainable Cities
Slum Upgrading

Understanding the History of Slums

The presentation looks at the main

Issues which the lecture addresses
Slums are the physical manifestation of urban problems related to poverty and/or inequality. Yet, little effort has been placed on linking the historical sequence of urban planning programs and design practices that emerged in the 19th Century and have since evolved in methods and practices to address the challenges of informality. This lack of emphasis in historical precedents – in their success and failures – weakens our ability to understand the meaning of informal urbanization within urban history.

Short analysis of the above issues
Architectural design is increasingly paying attention to slums; though it is unclear how spatial disciplines can go beyond the physical provision of housing, infrastructure or services. Despite the number of renowned and impressive interventions recently built at informal settlements throughout the world, slums today represent an epistemological gap for spatial disciplines because it is still hard to assess the role of design in solving social problems tied to poverty and inequality. One way to understand this relationship is to looking at the ways physical and social problems at slums have been understood.

Propositions for addressing the issue
The presentation portrays a historical sequence of five urban planning and design paradigms that have historically responded to the evolving nature of slums. During the presentation I will use particular cases to analyze the evolution and types of these paradigms as a response to urban problems throughout the 20th century.

The first is the paradigm of the “poor laws” and “poor housing” responding to the rural homeless in industrializing nations in the 19th century; the second is the paradigm of slum clearance programs at the beginning of the 20th century; the third is the paradigm of urban redevelopment as a response to the problem of blight between 1930s and 1960s; the fourth, now on international development, is the paradigm of self and mutual help housing from the 1960s and 1980s; and the last one is the paradigm of urban and integral upgrading from 1980s on. All these periods are closely tied to the disciplinary development of urban planning and architecture, and overall show how slums have been an underlying problem to modernization that continues and transforms throughout the last century.

Additional Reading Materials
Mike Davis, Planet of Slums (2004)
Gilbert, Alan (2007) The Return of the Slum: Does Language Matter?
Roy, Ananya (2005) Urban Informality: Toward and Epistemology of Planning
Pieterse, Edgar (2010) Filling the Void – Towards and Agenda for Action on African Urbanization