Measuring urban form

For many, the notion of ‘measuring urban form’ will sound disturbing. Urban form is about visual images of cities, experiences, feelings, memories of place, thoughts and intellectual constructs anchored in the realm of the arts and the humanities. Anne Vernez Moudon however gives in the paper Urbanism by numbers (2009) a good argument to study the urban environment quantitatively as it offers urban designers the opportunity to practice their art with its due precision. Urban density is one of the measures that is used frequently in urban design practice, but is also questioned by many as it relates poorly to urban form (Alexander 1993, Forsyth 2003). The use of a concept with such a large “warning disclaimer” is disturbing. The Spacematrix method has contributed to a clarification of the existing Babel-like confusion in the terminology currently being used by urban planners working with urban density. The most important contribution of the Spacematrix method is, besides a clear definition of density, that density can be related to urban form and other performances and that urban form is thus measurable.UrbanismArchitectur

Studying land-use distribution and mixed-use patterns in relation to density, accessibility and urban form

Mixed use development, one of the “mantras in contemporary planning” is a multi-criterion and multi-scalar concept which has various definitions. For this research mixed-use is defined as functional mixed-use and our main interest is to understand the spatial conditions needed to increase the diversity of uses (mix) by combining compatible functions. To analyse the compatibility of land uses and the importance of specific spatial conditions, the three most relevant factors of urban form are chosen: density, accessibility and mixed-use composition. The chosen factors are measured by methods of spacematrix, place syntax and MXI, using the city of Rotterdam (southern part) as case study. The three levels of analysis that are used are: (1) between all the urban blocks, (2) between mixed-use and mono-functional blocks, (3) within different types of mixed-use blocks. The results demonstrate interrelationships between the intensity of land uses on different scale levels. For example, residential density in a biking neighbourhood (radius 1.000) correlates to the density of commercial services in the same or a lower radius, but with of density of cultural and recreational services in a higher radius. In other words, cultural and recreational services need a larger catchment. Furthermore it is demonstrated that mixed-use blocks are denser and have higher accessibility to residential/work and commercial functions. Concerning mixed-use blocks, the results demonstrate a complementary behaviour between the existing functions within a mixed-use block and its surrounding. For instance, blocks with a bi-functional mix of housing and amenities are located in the vicinity of blocks with more work opportunities and blocks consisted of housing and working have a higher access to amenities in their surrounding. Identifying such spatial interrelations between land uses can be of great importance for urban planning and design. It can assist in the process of decision making by providing answers to the questions such as: If we want to create a city centre here, where should we improve accessibility then? Or, where should we, based on the existing distribution of shops, increase the residential density to use the existing potential best?UrbanismArchitectur

Spacematrix: Space, Density and Urban Form - revised edition

Spacematrix explores the potential of urban density as a tool for urban planning and design.This revised and extended edition of Meta Berghauser Pont and Per Haupt’s 2010 volume includes an extensive analysis of the relations between density, urban form and performance – a prerequisite for understanding and successfully predicting the effects of specific designs and planning proposals. The density database that is an integral part of the book has been expanded and now includes 142 examples from five capitals in Europe as well as examples from Asia.Berghauser Pont and Haupt demystify the use of concepts such as ‘urbanity’, ‘compact city’ and ‘park city’ by challenging the reliability of such concepts and critically examining the possibility of redefining them through quantification using multiple density measures.Spacematrix is of interest to professionals working in the field of urbanism, such as architects, urban planners and designers, as well as developers, economists, engineers and policymakers. It also offers researchers a method to quantitatively describe urban form and connect this to a wide range of performances.OLD Urban Composition

Space, Density and Urban Form

The concentration of humans – in some cases judged as too high, in others not high enough – and the problems connected to this, have resulted in discussions on density. Prior to the 20th century, density in European cities was merely an outcome of complex circumstances. During the second half of the 19th century, high densities in industrializing cities were argued to be one of the major causes of fires, diseases and social turmoil. In this period, density was introduced as a tool to analyse and diagnose the quickly growing and often overcrowded cities. In a following period of increased state intervention, the concept expanded into an instrument used to propagate alternatives and prescribe maximum densities in order to guarantee certain physiological and social qualities of urban environments (such as air, light and privacy). We can observe a shift from urban density as a mere result of city development and migration to a tool used to analyse problems; and, later on, to an instrument applied to offer improved solutions. More recently, minimum densities are argued for to support amenities and public transport, and as part of the solution to produce more sustainable urban environments with potential for vital human interaction (‘urbanity’). In spite of the practical advantages of the concept of urban density in urban planning, critics have argued that the use of density for anything but statistical purposes is questionable, as it is perceived as a too elastic concept. Many professionals, as well as researchers, hold the opinion that measured density and other physical properties are independent of each other. Besides the argued lack of relationship between density and form, density is also considered with suspicion because of the confusion regarding the definition of plan boundaries and the scale at which these are measured. There is no one accepted measure of density in or shared by different countries. This research takes off with a critical review of the origin, content and practical usefulness of the concept of urban density, and aims at revising and reviving the concept to the benefit of both the planning and design process, and scientific research. This doesn’t mean that an old instrument is just taken out of the basement, dusted off and reignited. No, the shortcomings of the existing density measurements methods in conveying information about urban form and performance are certainly very real, as others have pointed out. Those shortcomings, however, have led many to the conclusion that the concept as such is flawed and even dangerous. We insist, though, that the problem with the most commonly used density measurements methods is one of representation and resolution, and not of the concept itself. The development of the Spacematrix method to measure density and identify a series of associated properties is the main result of this research. We have redefined density as a multivariable and multi-scalar phenomenon to counter the existing Babel-like confusion in the terminology currently being used by those working in the urban field. Further, through the use of this multivariable and multi-scalar approach, density can be related to potential urban form and other performances. This makes it possible to reposition the concept of density in the field of urban planning and design, and research. From an instrument to prescribe the programme of a given area, density can become a tool to guide both quantitative and qualitative ambitions, and thus fuse urban planning and design into true urbanism.UrbanismArchitectur

Can spatial form support urban ecosystem services: Representing patches and connectivity zones for bees using space syntax methodology

UrbanismArchitecture and The Built Environmen

Where, how and why to intensify the city: Applying regression modelling to estimate intensification potentials

UrbanismArchitectur

Quantitative comparison of cities: Distribution of street and building types based on density and centrality measures

It has been argued that different urban configurations-planned vs. organic, treelike vs. grid like-perform differently when it comes to the intensity and distribution of pedestrian flows, built density and land uses. However, definitions of urban configurations are often rather abstract, ill-defined and at worse end in fixed stereotypes hiding underlying spatial complexity. Recent publications define morphological typologies based on quantitative variables (e.g. Barthelemy, 2015; Serra, 2013a; Gil et al., 2012; Berghauser Pont and Haupt, 2010) and solve some of these shortcomings. These approaches contribute to the discussion of types in two ways: firstly, they allow for the definition of types based on multiple variables in a precise and repeattable manner, enabling the study of large samples and the comparison between both cities and regions; secondly, they frame design choices in terms of types without being fixed and so open up for design explorations where the relation between the variables can be challenged to propose new types. This paper explores the typologies defined by Serra (2013a) and Berghauser Pont and Haupt (2010) further, as these target two of the most important morphological entities of urban form, namely the street network and the building structure. The purpose is to gain a better understanding of how types are composed and distributed within and across different cities. The method is based on GIS and statistical modeling of four cities to allow for a comparative analysis of four cities: Amsterdam, London, Stockholm and Gothenburg. For the street network, we process the Road-Centre-line maps to obtain a clean network model, then run segment angular analysis to calculate the space syntax measures of betweenness at different metric radii, defining the "centrality palimpsest" (Serra, 2013a). For the building structure, we process elevation data to obtain building height, then run accessible density analysis for all building density metrics (FSI, GSI, OSR, L) using the Place Syntax Tool (Berghauser Pont and Marcus, 2014). The street and building types are defined using cluster analysis (unsupervised classification), following a similar approach to Serra (2013a). The result is a typology of street ('paths') and building types ('places'), with different profiles of centrality and density across scales. The spatial distribution and frequency of these types across the four cities gives an objective summary of their spatial structure, identifying common as well as unique traits.OLD Urban Composition