Towards a theory of natural occupation: developing theoretical, methodological and empirical support for the relation between plot systems and urban processes

Doctoral thesis, 2019

Plot systems (or ‘plots’, ‘lots’, ‘parcels’, ‘land divisions’) is a commonly recognised structural component of urban form along with streets and buildings. They play a critical role in understanding urban processes in cities, not least of all because they link directly between the physical world and institutions, such as property rights.

The role of plots and plot systems in urban processes is addressed in this thesis as the theory of natural occupation. The theory argues that the structure of plot systems is the driver of a process of economic concentration and diversification of economic activity in cities, as described in the burgage cycle concept (temporal evolution of built form) and the spatial capacity concept (link between plot shape and urban diversity).

However, plot systems remain the least studied component of urban form, which this thesis contributes to on two levels. Firstly, by developing more precise quantitative descriptions of plots and plot systems by way of morphological measures and plot types. Secondly, by making use of these descriptions and empirically testing some central ideas in urban morphology, such as urban diversity. The thesis thus contributes to methodological and theoretical development in the field of urban morphology. However, it also demonstrates how these ideas on urban morphology can be a central contribution to theories in other fields addressing urban processes, such as urban planning and especially urban economics. 

The research design of the thesis involves the development of a generic method to spatially represent plot systems, the identification of three key morphological variables of plots based on extensive literature review in the field of urban morphology, the development of analytical plot types using statistical methods of data-driven classifications and finally, empirical testing of the theory of natural occupation (by correlating the morphological variables and plot types with the concentration and diversification of economic activity in five European cities). 

The empirical studies provide support for a direct relation between the shape and structure of plot systems and economic processes in cities and are an important contribution to urban design and planning practice.