
Nevertheless, Cerdà’s layout of streets and avenues has prevailed. The evolution of the city differed from Cerdà’s proposal, partly due to unexpected increases in population density, the built environment, and higher amounts of building occupation.

In addition, topographic maps from 19 are used to study the development of the expansion up to when it was fully developed. The second part uses location theory and a geographic information system (GIS) to analyse the pattern of location and the population served by markets and hospitals. The first part of this paper introduces the urban and political preconditions of Barcelona and the statistics on which Cerdà based his contribution. In his proposal for the new city, he planned the location of services such as marketplaces, schools and hospitals. The high mortality rates of the working‑class population and poor health and education conditions pushed Cerdà to design a new type of urban planning, which he defined as “urbanism”. Cerdà based his expansion proposal on an in‑depth socio‑statistical study of old Barcelona’s population conditions. This paper examines Ildefons Cerdà’s 1860 Plan for the Urban Expansion of Barcelona specifically, how and why it was conceived in a unique way, in which the provision of services to the population was an important part. " What matters now is to consign the characteristic forms of the house at the time we are speaking, because it is very shocking at first sight, we are interested to know, that what we find in some urban construction and in certain circumstances, is incompatible with civilization, culture and mores of our times. For Cerdà 1, the object of " urbanization " 2, a new scientific field of study can be summarized in To give an idea of the development in the field of science, we say that its constituent elements are shelters (intervia), its object is reciprocity of services and its means, the common pathways (vías), ie common use " (Cerdà, 1867:vol I, 44-45). In the context of this conference we will focus on the "intervia", in the building and we will try to study, to what extent, Cerdà includes the popular construction.

Instead, we focus our attention on some of the methodological procedures of Cerdà less widespread but that are essential for development, not only of his Reform and Expansion Project for Barcelona, but also for the articulation of his theory. In this paper we will not address nor the aspects of "planning" inherent to the Cerdà's project nor the derived aspects of his thinking on the discipline of "urbanization". However his work is becoming recognized as essential in the deployment of this field of social and economic practice and of research now called urbanism. Ildefonso Cerdà's work has been undervalued in the context of the historiography on urbanism.
