City, Territory and Architecture

An interdisciplinary debate on project perspectives

City, Territory and Architecture Cover Image
Open Access

In-formalised urban space design. Rethinking the relationship between formal and informal

City, Territory and ArchitectureAn interdisciplinary debate on project perspectives20163:20

DOI: 10.1186/s40410-016-0046-9

Received: 9 September 2016

Accepted: 4 October 2016

Published: 22 October 2016


This paper investigates the relationship between the formal and informal spheres of urban life and explores the change in the relation between them. Starting with a study of the evolution and different interpretations of the spatial concept of informality, we moved from a perspective based on the traditional dichotomies to concentrate on the relations between formal and informal. In this intermediate space the presence of these two dimensions can sketch out spheres of action and foster the emergence of different perspectives from an urban, cultural, social and economic viewpoint. Urban informality challenges the formalisation of the current design and planning processes that, based on abstract techniques and theories, create a system devoid of contact with reality. Informal urban processes appear to be an important perspective from which to depart to reconfigure criteria and approaches linked with space design. In this respect, urban design—thanks to its ability to intercept single and episodic phenomena, tendencies or behaviours and steer them towards perspectives of change—is subject to a dual tension between the formal sphere of knowledge and the need to analyse and endorse reality in its variety of informal aspects and forms. This approach fosters the establishment of alternative points of view and brings forth a different awareness, strictly connected with action, which can contribute to defining perspectives for the city.


Formality Informality Formal-informal relationship Urban design Borderlands Intermediate space Urban perspectives


Informal practices and urban processes

The current methods of reading, interpreting and designing the city refer to the traditional formal instruments of the discipline, picking out a series of parameters and standards not always able to decode urban complexity and describe reality that is detailed and changing, that builds up, falls apart and reassembles itself rapidly. This happens because the formal character of the usual systems of knowledge, analysis and design can be traced back to a functionalist paradigm based on the idea of a centralised, hierarchical control of the city. Firm, comprehensive codes govern the knowledge of urban processes, which tend to be “formalised” to be subsequently handled by space design. This practice, based on formal models and abstract principles applicable to different situations, runs counter to the current tendencies of the city, which is projected towards less formal, more flexible spatial order, favouring the passage from a strategic method towards an approach of the tactical type (De Certeau 1984). In the book The Practice of Everyday Life, De Certeau (1984) introduces the difference between strategy and tactic: “I call a “strategy” the calculus of force-relationships which becomes possible when a subject of will and power can be isolated from an “environment”. A strategy assumes a place that can be circumscribed as proper and thus serve as the basis for generating relations with an exterior distinct from it. Political, economic, and scientific rationality has been constructed on this strategic model. I call a “tactic”, on the other hand, a calculus which cannot count on a “proper”, nor thus on a borderline distinguishing the other as a visible totality. The place of a tactic belongs to the other. A tactic insinuates itself into the other’s place, fragmentarily, without taking it over in its entirety, without being able to keep it at a distance. It has at its disposal no base where it can capitalize on its advantages, prepare its expansions, and secure independence with respect to circumstances” (De Certeau 1984, pp. 19–20). According to this view, urban complexity is analysed as the relation between spatial form and social, economic and cultural processes.

In this context the traditional forms of the “static” city, understood as a built, permanent environment, become the background of the “kinetic” landscape (Mehrotra 2008, 2010) of an informal city that is temporary, cannot be coded, and is in continuous movement. It is a case of two worlds that co-exist on the same urban territory, and public space becomes the place where they intersect and enter into relations, giving rise to a single entity (Mehrotra 2003). In contemporary urban landscapes the kinetic city may be described as an entity made up of mobile spatial forms, and is continuously changing. Informal space takes shape over time occupying different areas and its borders may expand to include the multiple uses of the contemporary urban condition. The informal city, moving towards greater attention to the social aspect, introduces a sense of place and greater awareness of the contemporary world. Instability, indistinctness, dynamism, mobility, temporariness, recyclability and reversibility (Mehrotra 2008) are the fundamental elements upon which this spatial concept becomes structured. The “static” city and the “kinetic” city can establish a much more complex spatial and immaterial relationship than their physical manifestation might suggest. This relation defines a space—included between formal and informal—that is fluid and ambiguous, characterised by processes that are difficult to decode, map or subdivide (Mehrotra 2008). Enclosing many phenomena and situations, interstitial space is a metaphor for a physical state of the contemporary city and enables the conception of urbanism as a foreseeable entity a priori to be surpassed. This condition enables us to understand better the hazy line between formal and informal, as well as the progressive change in roles of people and spaces in the urban society.

It is interesting to highlight the way each debate on informal space begins with the description of processes of marginality and with the identification of dichotomous terms. Actually, the discussion should begin with alternative ways of framing themes as concepts of hybridity, simultaneousness and coexistence. Hence, formal and informal order may both be considered legitimate, simultaneous ways of “making the city” (Landry 2006).

Informal dimensions of urban life

Informality and urban space

The term informality has taken on importance in the last 50 years, gaining different names, features and interpretations over time. The complexity of this concept involves many spheres; it is the term used to describe and theorise on not just the spatial aspect of the city but also its cultural, economic, social and political organisation (Hernández et al. 2010). Informality is often associated with procedures and phenomena that take place outside formal processes or planned and regulated zones (Roy 2005). A very wide range of situations may be included, like spontaneous processes of occupation of the territory, absence of property titles, self-building of houses, illegal inhabiting in contexts with rapid urbanisation, temporary uses of space, forms of self-organisation and development of urban areas at city edges, etc.

The informality phenomenon has become a significant element in urban growth and in the “production” of the city (Lefebvre 1991). This concept became important when the first city expansion plans began halfway through the nineteenth century, and with the success of a series of normative frameworks regulating urban development and some practices considered ‘edge’ practices in the past.

A considerable amount of research has tried to analyse the alternative methods of aggregation and sharing public spaces within the city. In particular, the Chicago school of urban sociology examined the development and change in human behaviour brought on by the physical and social environment. In the essay Urbanism as a Way of Life, Wirth (1938) maintained that while the city is the “place of urbanism”, the urban way of life is no longer confined to the physical entity. Urbanism is not considered a process by which people are linked with a place, but as the outcome of a wider system of relations deriving from a few variables that determine the urban condition as they interact with each other. These aspects appear important also to understand the category of urban informality.

The notion of informality became firmly established in the debate on the city in the early 1960s, as an alternative to the functionalist urbanism proposed by the CIAM (Congrès Internationaux d’Architecture Moderne). In the 60s, in particular, population growth and the rapid spread of the first informal spatial forms coincided with the loss of certainties regarding the paradigms of urbanism and modern architecture.

Among the most significant avant-garde activity of the early 60s we find the work and projects of the members of Team X, an entity deliberately not structured, which originated within the sphere of the latest CIAM meetings with the aim of discussing and processing ideas and documents combined on architecture and urbanism. Team X highlighted the importance of certain aspects neglected by Modern Movement functionalism, like social requirements, spontaneousness, self-organisation and the opening up of design to many future spatial possibilities. The contribution of the architect Aldo Van Eyck was especially important: on the occasion of the 11th CIAM held in 1959 (Otterlo, Holland), this member of Team X exhibited a table depicting a plan of a pueblo settlement, a population present at the border between Mexico and the United States. The diagram, known by the name of Otterlo Circles, referred to an informal settlement form and showed how the inhabitants collectively inhabited the space.

Focusing on informal knowledge of the territory led Aldo Van Eyck to concentrate his research in the early 60s on the Dogon villages in Central West Africa to analyse the relation between social structures and built environment. The most important aspect of these villages is the resident population’s ability to give shape to a shared landscape with which they satisfy collective needs, in the absence of any type of regulation on space structuring. These informal processes and evidence show a capacity on the part of the inhabitants to establish a relationship between territory, space and practices.

Aldo Van Eyck’s most important project connected with the concept of informality is The City as Playground. Between 1947 and 1978, the architect designed a system of playgrounds, based on a representation of the urban gaps in the city of Amsterdam. These interventions were carried out on temporarily unused sites, but their meaning goes beyond the creative solution of the moment. First of all, the playground proposes a different conception of space. Van Eyck designed an open space that could be interpreted in different ways with the aim of stimulating the users’ creativity. The second aspect is the modular nature of the project: the basic elements can be combined in different ways and depending on the requirements of the local context. The third aspect is the interactive relationship with the surrounding urban fabric and the “interstitial” nature of the project, which overthrows the urban system proposed by the CIAM in favour of a bottom-up approach (Lefaivre et al. 2002; Lefaivre 2007). Thus the experiments developed in the Amsterdam playgrounds were not determined a priori, but were defined as the outcome of the process of participation that involved citizens and institutions. Not being located in an area pre-determined for this function, these interventions fit into the interstices of the urban space, in which the gap addresses design as a procedure for reading the social and spatial matrix. A further significant aspect is linked with the fact that these playgrounds were not created to establish individual units but, rather, to set up an extensive polycentric network. The importance of this work should also be traced back to a different conception of public space based on practices started up by parts of the community and the development of forms of micro-urbanity.

The concept of informality is also mentioned in the theoretic models developed between the 50s and 60s, in which the Situationist International, a movement operating in the political, social and artistic fields opposing the effects of functionalist planning, formulated new approaches for the social space of the city. Situationism proposed radical actions through the search for mobile urban spaces and an architecture that could be transformed in harmony with the desires of the inhabitants. These avant-garde ideas have a clearly playful nature; they were centred on the need to link up the built environment with the context and conceive of space as a product of social activity. The main purpose of the movement was to create “situations” (Holmes 2007), defined as moments of life concretely and deliberately constructed by the collective organisation of a single environment and the play of events.1

The Situationists took up the practice of urban wandering again, defining it “psychogeographical dérive”. This consisted of an exploration of the city aimed at understanding the effects of space on the individual and his behaviour, the separation of the social aspects of the topography and the effective dimension of built spaces, and at acknowledging the psychic effects of the urban context (Careri 2001). In the dérive proposed by the Situationists the modern condition of the city is celebrated, in which public spaces have ceased to be the place of dialogue and exchange, to become an unforeseeable fabric determined by multiple itineraries. The dérive is a spatial experience that starts with the figure of the flâneur, introduced by Baudelaire and Benjamin, but proposes a new condition, a route dictated by indeterminacy and chance, an indifference that enables the city to be explored using a map that is not the traditional one, as appears clearly from the plans of Debord’s Naked City and New Babylon by Costant (Sadler 1999). The figure of the flâneur, as well as bearing witness to a bewildered human condition, highlights the desire to understand the city going over and above the traditional interpretative categories and experimenting with new relations with the territory (Benjamin 1986, 2010; Nuvolati 2006). Through these representations the world ceases to appear as an object in itself, but is defined more and more as a background, which cannot be separated from social behaviour and structure (Maciocco and Pittaluga 2001).

The passage from a functionalist approach to one more attentive to understanding urban complexity, typical of the Situationist movement, appears perfectly clear in the research developed from the 60s onwards by Andrea Branzi. This author suggested passing from “strong, concentrated” modernity, typical of the nineteen-hundreds, to the current “weak and widespread” type, dwelling on the importance of devising reversible, evolutive, temporary, imperfect and incomplete projects, as close as possible to the needs of a society able to continuously reprocess its social and territorial situation, casting off the old and reassigning new functions to the city (Branzi 2006). As Branzi emphasises, this entails “less compositive and more enzymatic” projects, able to fit into the processes of transformation of the territory without being based on external figurative codes but rather on internal environmental qualities, dispersed over the territory and not enclosed within a perimeter established a priori.

This inclination to work according to a “weak and widespread” logic does not imply any negative value of inefficiency or incapacity; it simply indicates a particular process of modification and knowledge that follows logics that are natural and non-geometric, processes that are widespread, not concentrated, and strategies that are reversible and self-balancing (Branzi 2006).

The No-Stop City project, proposed at the end of the 60s by the Archizoom Studio represents a radical view of the city of the future. The research places the formal questions linked with the figurative codes of the discipline in the background, favouring a non-figurative approach (Branzi 2006). Starting with a critical analysis of metropolitan reality of the 50s–60s, serial production models in evolution were proposed. By the repetitive multiplication of some modular elements new spatialities were defined. Though inspired by a criticism of the ideology of the functionalist models, the fruit of a serial repetition of elements, this project represented urban territory as an open, temporary system, a non-formal reality in which energy may arise that is able to create hybrid and complex structures, rich in a multiplicity of functions and uses.

“The need of cities for a most intricate and close-grained diversity of uses that give each other constant mutual support, both economically and socially” (Jacobs 1961, p. 14) is highlighted in the book The Death and Life of Great American Cities (1961), in which Jane Jacobs investigated the functioning of the city based on the social behaviour of inhabitants and their interactions. “The look of things and the way they work are inextricably bound together, and in no place more so than cities. […] It is futile to plan a city’s appearance, or speculate on how to endow it with a pleasing appearance of order, without knowing what sort of innate, functioning order it has” (Jacobs 1961, p. 14).

The study of informal dynamics proves more effective for the purpose of understanding urban phenomena with respect to the traditional “methods of urban redevelopment and planning” that totally disregard people’s “real life”. The idea of a place, its deep meaning or vocation is not the space defined by designers and architects, but the place of experiences and livability (Jacobs 1961). In the empirical research developed by Jacobs the concepts of neighbourhood and space-sharing rediscover in the street element a fulcrum for the construction of a collectivity based on the informal uses that appear in the contemporary city and territories.

A further reference to help us understand the phenomenon of informality can be found in John F.C. Turner’s studies in Peru in the early 60s. In his research on the barriadas of Lima the author analysed the changing and forming of entire informal districts and the features these processes took on within the urban structure. The most significant aspect of Turner’s research lies in the identification of some potential in the informal settlements and their acceptance as a possible alternative to the problem of inhabiting. In the book Housing by People Turner (1978) criticised the traditional ways of inhabiting, characterised by poor flexibility, conveying what Mike Davis defines as “illusions of self-help” (Davis 2006, p. 69): when the inhabitants can contribute to decision-making processes and project achievement, the resulting environment appears as the positive outcome of social and spatial relations.

During the 70s and 80s the phenomenon of informality was handled not so much within the urbanism and architecture sphere of studies, as in disciplinary sectors like sociology, anthropology and economics. The idea also spread, illustrated better below in the dualist approach, according to which informality converged with non-planning and arose through the occupation and illegal transformation of space and as such contrasted with traditional forms of planning (Castillo 2001), thus ignoring the complex system of dynamics contained in the relations between formal and informal.

The relationship between informality and urban design has recently been the subject of renewed interest. In 2008 an issue of the Harvard Design Magazine (Saunders 2008) observed that design could be an important element to improve quality of life in the informal city, focusing on some significant expeDe Certeauriments that highlighted how informality had become one of the important components of the debates on the contemporary city.

Among the issues of greater interest we can pick out those developed by Rem Koolhaas. In his study on spontaneous urbanism in Lagos the architect described the spontaneous forms of self-organisation of the city as a “comfortably disorganised” structure (Various Authors 2000). In this research the creative capacity of residents and their inclination for survival and work were enthused over, as well as the need to pay attention to informal practices and phenomena that were present in the city.

The analysis of the Lagos metropolis also highlighted that some systems and factors considered marginal, liminal, informal or illegal in the traditional ways of conceiving the city may, on the other hand, represent an opportunity, if fit into a different perspective. Roy (2011) points out, however, that this research established a considerable division between the traditional city design methods and spontaneous practices, favouring the creation of subaltern urbanism, considered by Koolhaas the non-complementary alternative to the traditional forms of city. In this respect, the chaotic forms of the city contain within them absolutely rational logics of expansion and appear as autonomous systems of urban development.

This decisive surge towards self-organised forms and economies may also be associated with the “heroic entrepreneurial spirit” proposed by de Soto (2000). According to this author, there are entrepreneurs in Third World Countries who have talent, enthusiasm and the ability to make profit from “nothing”. The obstacle that prevents them from creating capital is linked solely with the absence of a system of recognition of property and the consequent impossibility to convert it into capital. The process of “formalisation” of informal properties may favour the creation of new institutions and constitute an open system of properties easily accessible to everyone. De Soto interprets the informal economy as a rebellion from the bottom that will oppose the traditional capitalist system. In the same direction, Davis (2006) defines a future perspective based on a conflict for survival, a struggle between formal and informal that will actually start to develop in the slums.

The concept of informality is also one of the themes proposed by Alejandro Avarena at the Venice Biennial, 15th International Exhibition of Architecture to describe the present and future of the city. Entitled Reporting from the Front, the Biennial aimed to offer a contribution, by means of some significant project-based experiments,2 to the many challenges on which urbanism is called to provide answers (Various Authors 2016). The exhibition Report from Cities: Conflicts of an Urban Age, set up by Ricky Burdett, recalled the most important tendencies and conflicts currently underway in the urban sphere, amongst which the opposition between formal and informal emerges. The exhibition selected some metropolises, highlighting with maps showing spatial change how they have altered within a time-frame of 25–100 years and how most of the urban growth of recent decades has been characterised by the presence of informal phenomena. On the one hand, certain processes of informality in urban space are illustrated, and on the other, examples of formalisation leading to privatised configurations of the space and to the formation of structures like the gated communities, enclosed residential areas patrolled by police and devoid of relations with the surrounding space. The recurring element of the exhibition shown in the pavilion of cities involves the awareness that it is not possible to handle the complexity of the city by reasoning on the extreme poles of dichotomies, like, for example, formal and informal, but there is the need, rather, to understand how architecture and urbanism can be restructured to provide answers for uncertain, indefinite social, economic and environmental conditions.

The reflections made by Koolhaas (Various Authors 2000), De Soto (2000) and Davis (2006) have referred to a formal/informal approach of a contrary dichotomous type. In contrast with these tendencies urban complexity may be dealt with from a wider viewpoint (Various Authors 2016) and informality may be understood as a way of inhabiting the territory (Alsayyad 2004), a way of producing space made up of a series of transitions that link a variety of economies and places to others. It is not a case of a simple connecting line but a continuum between formal and informal, characterised by a fractal type of approach. “The splintering of urbanism does not take place at the fissure between formality and informality but, rather, in fractal fashion, within the in-formalised production of space” (Roy 2009, p. 82).

In this sense Hernández et al. (2010) considers informal settlements as relational spheres in which in-between space materialises (Bhabha 1994), an intermediate space (Maciocco and Tagliagambe 2009; Tagliagambe 2008) between two conditions in which different forms of creativity may become manifest.

Another way of conceiving informality may arise when the State tries to intervene to suppress or attack it. Yiftachel (2009) reflects on the meaning of informality in the Palestine/Israel context, identifying it as a grey space. “Urban informality is a ‘gray space’—positioned between the ‘whiteness’ of legality/approval/safety, and the ‘blackness’ of eviction/demolition/death” (Yiftachel 2009, p. 89). These grey spaces are permanent areas at the city edges that can be dealt with by corrective policies of compensation or by delegitimisation and criminalisation arguments. Understanding the grey space helps us to conceptualise two associated dynamics which the author defines as “whitening”, or approval, and “blackening”, or destruction. The first alludes to the tendency of the system to “recycle” grey spaces created by powerful or favourable interests, and the second refers to the State process of “resolution” of the problem aimed at turning the grey space into black space (Yiftachel 2009).

The reflections put forward by Roy and Alsayyad (2004), Hernández et al. (2010) and Yiftachel (2009) highlight that planning practices are not separate from informal ones, but rather constitute integral parts of a single system of relations. Studying deeper the evolution of the concept of informality below, we will illustrate the passage from an oppositional model, characterised by the contrast and exclusion of the two formal-informal spheres, to a dialogical one, more attentive to understanding the relations between them.

Urban informality: a challenging concept

It appears rather complicated to give a universal definition of the concept of informality. Since the 60s of the last century—the period in which the term was used for the first time—informality has appeared as a social and economic phenomenon difficult to interpret, especially when attempts to tackle it used analytical instruments belonging to a single discipline (Coletto 2010). The first debates on informality focused on informal employment and the economic aspects connected with it, neglecting the spatial sphere and the emerging forms of urbanity. It was evident from the first definitions of informality that scholars were unable to describe a wide range of people, activities and spaces, with features not clearly identifiable, unless they used a dualist approach.

The conceptual frame analysing manifestations of informal processes of the urban system initially developed in the sphere of research on developing countries. The term “informal economy” was used for the first time in two international pieces of research carried out by the United Nations ILO agency (International Labour Organization): the first, the report Informal Income Opportunities and Urban Employment in Ghana, was the result of research done during the years 1965–1968 by the English anthropologist Keith Hart; the second, Employment, incomes and equality (1972), consisted of research performed in Kenya (ILO 1972) in the early 70s which involved various ILO experts and researchers and dealt with sketching out a picture of informality conditions, with particular attention to the less developed countries. It is important to note, however, that the ILO completely neglected the dynamic aspect of the phenomenon, limiting itself to confirming the dichotomy between what is formal and everything that is not, and giving rise to the dualist approach. Also, in this early research importance was not given to the informal sector as a sphere of analysis; it was only observed in relation to other study programmes. The ILO concentrated, moreover, on the visible implications of informality rather than its causes, giving the concept a meaning that was standardised for certain features.

The period between the 70s and 90s of the last century was marked by a concentration of theoretical studies that modified the approach to the concept of urban informality.

As informality was described by a number of theoretical and empirical approaches, it gave rise to some schools of thought. The different positions did not follow a linear pattern over time, but overlapped each other depending on the various local contexts. Three phase scan be picked out in which some views of informality were predominant over the others. In the first phase, between the 70s and 80s, we find the dualist school, which conceives of informality as a group of marginal activities excluded from the formal economy. The second phase, during the 80s–90s, was characterised by the spread of various interpretations. Among the most important we find the legalist approach, characterised by the view of informality as a set of positive forces in a formal context linked with power strategies, and the Structuralist school which, though considering informality an integral part of a single system, referred solely to the economic field. The 90s represent a pause in the debate on informality, while in the twenty-first century a phase has begun that is distinguished by renewed interest for this phenomenon (Roy 2005) and in particular for its relations with the globalisation processes that are changing the economic, social and political geography of the world.

Formal-informal dichotomous models

The traditional ways of reading the city can easily be traced back to dichotomous interpretative categories, which, though fundamentally important for understanding urban phenomena, are structured on a binary pattern based on the definition of certain privileged axes of spatial, social, economic and cultural organisation. These categories have carried out a descriptive function in the analysis and construction of knowledge capable of simplifying urban complexity. According to this pattern, a sphere of interest is defined, based on which diverging or “other” experiences are highlighted, which go to make up the opposite dichotomous pole. Actually, this binary system of conceptualisation of the city shows an inability to define adequate perspectives for the contemporary urban condition.

The models opposing formal and informal consider informality as the unregulated, uncontrolled, untidy and inefficient use of space, in an antithetical position compared with the tidy, regulated and planned sphere. The formal-informal dichotomy, summarising a variety of social relations, spatial forms and urban economies, encapsulates a wide spectrum of situations within a binary structure. Hence, the term “formal” refers to assimilated spheres, specific forms, elements or procedures that, having been decoded, have become standard, the norm, rule or convention. Informality, on the contrary, introduced into the theoretical debate from the 60s onwards, is a concept that is defined, interpreted and conceptualised with great difficulty, due to the multiplicity of urban, social, cultural and economic meanings it can have. Of the complex dichotomous approaches, developed mainly in the economic sphere, only the most significant aspects for urban design will be highlighted.

Dualist approach

According to the dualist approach, informality is a sphere separated from formal or regular processes, made up of marginal and residual activities and able to provide a living for individuals or groups at the edge of society. In this approach these activities are destined to prosper only as long as the industrial sector continues to blossom. Hence we do not speak of “informal economy”, but of “informal sector”, conceived as “the part of the urban economy of less developed countries composed of individual, family or small-size enterprises. It provides the major source of employment in the cities, with salaries lower than the minimum level envisaged by the law and production processes presenting high intensity of work, little machinery, low investments and low barriers on entry” (Bellanca 2010).3

This approach may be traced back to the first investigations into informal economy fostered by the ILO in the 70s, in particular the Kenya Report of 1972. The purpose of the survey was to supply an accurate analysis of the informal panorama and draw up a series of guidelines. This research highlighted a set of criticalities. First of all, the survey focused on a strictly urban sphere excluding the areas outside the compact city. Moreover, although the approach addressed the social life of the city (Alsayyad 2004) and was allegedly multidisciplinary, in actual fact it favoured an economic type of approach, preferring simplified points of view and unable to grasp the complexity of the phenomenon. This dualist approach encouraged the emergence of a dichotomous perspective between formal and informal urban economy, devoid of any relationship between the two spheres.

Legalist approach

Arising from the dualist approach some alternative views of informality were generated. One of the most significant was offered by Hernando de Soto’s legalist school, which, not taking into account the preceding theories, brought forth an original way of conceptualising informality. In the book The Other Path (De Soto 1989) De Soto developed the thesis that informal economy was a response to inefficient State regulation of the economy. In a situation where it was difficult to become integrated into the formal economy, the inhabitants were forced to seek spontaneous and creative solutions. De Soto stated that the origin of informality was not to be sought in particular cultural, religious or social features, but in the inefficiency of the formal economy. “This extralegal sector is a grey area that has a long frontier with the legal world, a place where individuals take refuge when the cost of obeying the law outweighs the benefit. […] The poor are not the problem but the solution. […] What the poor are missing are the legally integrated property systems that can convert their work and savings into capital” (De Soto 2000, p. 89, 241). According to De Soto, in the countries of the south of the world there is a lack of property rights, an essential prerequisite for forming self-regulated markets and able to reduce uncertainties for investors. It is indeed this total inefficacy of the economic system that drives individuals to follow an informal type of approach. The heroic entrepreneurial spirit characterising this approach sees the informal sector as something closed compared with the formal one.

The alternative proposed by De Soto, beginning with a negative conception of State intervention, aims at deregulation of the informal sector. The analysis, though fostering an empirical study of the phenomenon, does not deal with the interactive relationship between formal and informal and describes the informal sector inaccurately, like a grey area with a long frontier opposing the legal world (Portes and Schauffler 1993).

The principal approaches contrasting formal and informal do not recognise the informal as a differentiated process bearing various degrees of diversification; they maintain the equivalence of informality and marginality. Duality, apparently useful for analysing phenomena from a general viewpoint, does not help us understand their complexity. There are many arguments that can be set down against these approaches. The departure point is the refusal of the concept of informal “sector”, in favour of the term “modality” of informal transformation. It is interesting to contrast the traditional dichotomy of the two sectors with the idea of informality as a series of processes and practices connecting different economies and spaces (Roy 2005; McFarlane 2012).

Formal-informal dialogic models

Structuralist approach

At the end of the 80s, Castells and Portes (1989) focused on the structure of the relations between formal and informal. In contrast with the dualist school, which considered informality a set of marginal activities excluded from the formal economy, and the legalist school, which saw informality as a set of positive forces in a formal context linked with power strategies, the Structuralist approach asserted that informality was an integral part of a single system. In the Structuralist school the casting off of a dichotomous approach began to be glimpsed, opposed by reality made up of a dense system of relations between formal and informal, which, however, were explored mainly from the economic point of view. The Structuralists started up a series of research studies that, instead of considering official data and statistics, were based on empirical observations. The result of these investigations confirmed the existence of a number of original relations between formal and informal. This approach highlights how informality can no longer be considered a phenomenon found only in the countries in the south of the world (Coletto 2010).

Relational approach

Apart from the different interpretations given to informality, it is significant to note that the complexity of economic, social, spatial and cultural relations makes it impossible to work out an approach linked with a single paradigm, but it appears necessary to resort to logics based on multidisciplinary models.

From the concise relaunch of the main theoretical approaches that have dealt with the subject of informality since the beginning of the 60s, it becomes clear that this term has been susceptible to numerous interpretations. Nevertheless, in recent years new interest in the phenomenon has been seen to converge due to two factors (Chen 2006). Firstly, in spite of the prediction that it would be reorganised or even disappear, the informal economy has grown notably in many countries and in some cases has appeared in innovative forms and procedures or unexpected spaces. Secondly, this theme has come to light again in the theoretical debate as an element of strength to promote processes of economically and socially sustainable development. From a theoretical point of view, the continuous search for criteria to redefine informality has not enabled a concept to be formulated with universal value. For this reason, the term is often used with a negative sense, indicating not what it represents, but how it differs from the formal sphere. This negative connotation has not succeeded in putting the numerous research studies on the theme in the background; they have enabled a sort of “map” of informality and its multiple viewpoints to be created. In spite of the lack of conceptual clarity, the diversity of definitions and the tendency to categorise “formal” and “informal” as a dichotomy, the two terms have continued to be used widely to describe different phenomena. This analytical-descriptive process has highlighted the density of situations that characterise the borders between formal and informal and has enabled the dichotomous view of informality to be put into the background, shifting the attention onto the area of interconnection between the two poles. It therefore seems interesting to take into consideration the hazy, hybrid space, the privileged place of expression of diversity of these interactions.

Informality and urban project

Towards a socio-spatial continuum between Formal-Informal

Following this path and starting with the use that can be made of the two terms and their different characterisations, Ostrom et al. (2006) has defined a conceptual frame that has enabled the many definitions of formal and informal to be summarised within two groups of thought. The first trend considers the informal an element that is external to government mechanisms, and the formal as internal to these instruments. Whereas the second tendency considers the informal devoid of structure, and the formal, on the contrary, an organised system. In the light of these two parameters, i.e. the relationship with government mechanisms and the degree of structuring (Ostrom et al. 2006) shows some weak points of the two dichotomous approaches. In the first approach, the author emphasises the inadequacy of the measures adopted towards the informal, such as the processes of formalisation or legalisation of property, while in the second case she highlights the weakness in associating the concept of informality with that of disorganisation. This opposing perspective also relegates to the background the innumerable processes that involve phenomena and groups of individuals. It thus appears necessary to analyse the complex relations between the two spheres focusing on the formal-informal continuum (Ostrom et al. 2006).4

This position entails a shift of interest from the search for a single design underlying a multiplicity of events, typical of the dichotomous approach, towards the analysis of fracture phenomena, “that of the fracture and the limit, no longer that of the foundation that lasts, but that of transformations that serve as a foundation and renewal of foundations (Foucault 1969, p. 8).”5 The method proposed implies that it is impossible to pick out a straight chain of causes to define relations between phenomena. We are confronted instead with some series of events in which we have to define each time the elements, limits and relationships.

Ananya Roy has devised her own definition of informality stating that: “if formality operates through the fixing of value, including the mapping of spatial value, then informality operates through the constant negotiability of value and the unmapping of space” (Alsayyad 2004). This definition opens the way to a variety of interface and interconnection processes between the formal and informal sphere. The idea of informality as a way of life gives way to understanding the relations and interactions with urban development that give shape to and build up this system. Informality is not outside formal systems, but is produced by formal systems and always connected with them.

Abandoning a dichotomous approach to the analysis of urban processes entails a complete change of perspective: attention is no longer paid to the borderlines, namely to the differences and interdependence, but rather to the borderlands, areas of hybridisation and relational spaces between the formal and informal spheres. The borderlands category succeeds in explaining this process of hybridisation best. The concept differs from borderline, which crosses, cuts and separates space. The borderlands category refers to frontier areas where different spheres are activated and enter into contact. “They are spaces that are constituted in terms of discontinuities […]. In constituting them as analytic borderlands, discontinuities are given a terrain of operations rather than being reduced to a dividing line” (Sassen 2005, p. 83). Sassen (1994, 2001, 2006) describes the intersection between formal and informal urban economy as a terrain of discontinuity in which something new may be created from a cultural, social and economic point of view. It is a matter of border areas, characterised by highly dense social environments, whose dynamics are understandable only if the instruments of analysis based on traditional dualisms are put in the background. The overlapping areas build themselves up in their theoretical and methodological specificity; it is possible that both poles subject to the interaction subsequently enter into the process of reconfiguration (Perulli 2007).

In this regard, the formal-informal continuum is fundamental for understanding current urban development. At the moment in which elements of interaction between formal-informal are recognised, each dichotomous or dualist pattern falls apart in favour of mixed trajectories, a sort of “meshwork” (Ingold 2011), a weaving of “bundles of lines” (Deleuze and Guattari 1980) that becomes a vast, structured terrain on which new spatialities and different forms of urban life can be sketched out.

Urban informality and the production of space

In contrast with the tendency of some theoretical positions that consider urban informality an aspect alien to planning and design forms, and which study the impact of informal practices and activities according to a view limited solely to the establishment of forms of social-spatial segregation and inequality, the relational perspective between spheres enables us to analyse this spatial concept from different points of view. Informality cannot be associated solely with disorganisation and chaos phenomena or with forms of social disjointedness (Alsayyad 2004), but refers to a wider context and has distinctive features that permit its theorisation separately from the single geographies of places (Alsayyad 2004). To this end it seems important to highlight that spatial geographies are not to be understood as “geographies of features”, pre-established entitities that tend to identify the common traits of a particular condition, but rather as “process geographies” (Appadurai 2000), such as to identify an urban theory that goes beyond the simple localisation of urban phenomena and is capable of analysing and understanding the cultural, social, spatial and economic processes (Olds 2001).

The “formal” and “informal” categories cannot be analysed following a dichotomous oppositional perspective, like a normative power opposed to an incipient one, since “these poles, connected with the will of the social forces, structure the faces of the city with their borders”.6 (Chamoiseau 1992, p. 227) and are supported by a different relation.7 The relationship between the abstract spaces of the planned city (with its land uses, zoning, rules and formal processes) and the untidy reality of the informal spaces place the relation between informal and formal at the centre of attention. The latter recalls the difference, pointed out by Lefebvre (1991), between work and product. “A work has something irreplaceable and unique about it, a product can be reproduced exactly, and is in fact the result of repetitive acts and gestures” (Lefebvre 1991, p. 70). A work is created by a process that, though entailing some type of work, needs more than this; it needs an injection of forms of art and creativity; the product, on the other hand, is the result of serialised gestures, and is thus repeatable and reproducible (Chiodelli 2009). Formal planning, like the product, is the outcome of a deliberate process in which a central power proceeds from an abstract thought towards the direct application of the initial idea. On the contrary “the creative capacity in question here is invariably that of a community or collectivity […] a social reality capable of investing a space—capable, given the resources (productive forces, technology and knowledge, means of labour, etc.), of producing that space” (Lefebvre 1991, p. 115). As Chiodelli maintains (Chiodelli 2009), creativity is based on social practices, slow, contrasting, divergent but capable at the same time of producing a unitary social project, which becomes real in an urban space.

The contrast and distinction between work and product, like that between formal and informal, certainly has relative significance. Between these terms a more subtle relation exists, that is neither an identity or an opposition: the formal processes of planning supply precise rules and directions for structuring the territory, while informal ones model, occupy and generate space following principles like spontaneity and self-organisation. What relation exists between these two ways of structuring space? The movement that is triggered and in turn produces new social reality is based neither on formal or informal, but on their dialectical relationship in the space (Lefebvre 1991).

In this connection it is important to emphasise that it is not the single formal or informal processes that determine the positive outcome of the planning and design process for urban space, but rather the quality of the relations existing between the two spatial concepts. The informal, placing itself in a dialectical relation with the formal, configures relational spaces and defines a meeting point between two different ways of structuring society. No “creative capacity” on the part of a collectivity could exist, in fact, if a structural rule of everyday life did not exist. “If and when this dialectical (and hence conflictual) relationship ceases […] must come to an end […] the capacity to create” (Lefebvre 1991, p. 116). These categories cannot therefore be analysed according to an oppositional method since they feed each other in a totally reciprocal way. Informality is an organising logic (Alsayyad 2004) that can develop only in so far as there is a rule or formal structure that will favour its success. Hence the relation between formal and informal shows itself through interaction: their affinities and differences are in a state of equilibrium which is reflected in an irresolvable tension (Mehrotra 2010). Only by observing the phenomena characterising contemporary urbanism can we highlight the existence of the strong interconnection between the two spheres.

Michel Foucault (1969, 1977) also attempted to overcome a contrasting perspective between spheres and adopt a relational dimension with his analysis of power relations. Foucault overturned the question of power, opposing the perspective of sovereignty from above, typical of a formal approach, with that of decentralised, informal power that follows life in the apparent randomness of the day-to-day. It was not a case of formal power, exercised by a top-down approach, but a series of micro-powers spread at an everyday level, able to establish themselves in society and in the forms of culture and knowledge (Foucault 1977).

In this sense informality fits into the field of application of a “central power” (Roy 2009a) and only the latter may determine what is informal and what is not (Castells and Portes 1989). Roy (2005), recalling Agamben (1995), maintains that informality represents a condition deriving from the suspension of an order, rather than the chaos that precedes it (Agamben 1995). In this respect informality is conceived not as an object of regulation of the State but, on the contrary, a product or the outcome of this regulation, or as a state of exception.8 Only formal structures and rules have the power to determine what is formal and what is not (Roy 2005). Hence informality may be described as a planning strategy, or a planning language (Roy 2009b).

Urban informality, taking shape as one of the principal and most significant ways of producing urban space in contemporary cities and territories, highlights an issue around which it is essential to initiate some reflections. Informal practices challenge the formalisation of the current design and planning processes, which, based on abstract techniques and theories, generate a system devoid of contact with reality. Formal knowledge, underestimating the potential arising from possible interactions between formal and informal, currently seems unable to supply satisfactory answers on the changes underway in contemporary society. It therefore seems indispensable to focus on these spaces to try to understand to what extent planning, as a formalising normative power, may “learn” from the informal (Friedmann 1987). Some phenomena and experiences linked with urban informality are in effect potentially able to reconfigure a theoretical framework of analysis, planning and design based on the real uses in the city and on contemporary territories (Porter 2011).

Designing for the Space for relations between Formal and Informal: the San Diego-Tijuana experiment

A number of experiments have acknowledged and legitimised the potential of urban informality and consider the relational sphere between formal and informal a base for challenging the current paradigms of space planning and design. This is what is happening in some areas near the border between the United States and Mexico, where the ETC (Estudio Teddy Cruz, University of California-San Diego) and the NGO Casa Familiar have tried out an experimental research method concentrating on the spaces for relations between formal and informal.

The border between the United States and Mexico is a territory presenting a series of highly complex situations, where North American and Latin-American cultures enter into close contact/conflict with each other but are at the same time separated by a physical barrier, a wall, dividing them. This area may be defined as a space that is simultaneously permeable and impenetrable, featuring an inclusion/exclusion process (Davis 2006). The transnational metropolis spreading between San Diego and Tijuana also represents different ways of conceiving the city located on the same territory. The presence of the international border has led to two antithetic urban developments emerging, each of which with its own spatial, social, economic and cultural conformation. San Diego, with its suburban order, is the emblem of urban development based on separation, control and exclusion, implemented by the creation of surveillance infrastructures and characterised by sprawl; whereas Tijuana’s rising urban development shows informal settlements that have colonised the territory on both sides of the international frontier on a much lower scale, taking shape via heterogeneous, hybrid processes of juxtaposition and improvisation that attempt to oppose the wall separating these two realities.

The area of San Diego city close to the border with Mexico presents numerous informal settlements that are growing at a much faster rate than that in progress in the central areas of the city and based on the informal settlement model of Tijuana. In these spaces a process of reappropriation of the marginal territories is underway to transform them into more complex areas with alternative economies. Precisely this condition has encouraged projects to emerge for the space of action between formal processes and informal practices.

Beginning with identifying the tendencies towards change in space organisation and ways of life underway on the territory linked with the spatial concept of urban informality, ETC’s research suggests heterogeneous elements be introduced into San Diego’s current urban system to steer it towards prospective changes. This concept has taken shape, in particular, in a local urban acupuncture project (de Solà Morales 1999; Lerner 2003), following the principle that small interventions on a local scale may have enormous potential in activating more extensive and complex processes.

To be specific, this territorial project is a micro-sphere experiment in the San Ysidro district, a low-income community made up of families of Latin-American immigrants and situated close to the international border. The “Living Rooms at the Border” project proposed small systems be created possessing a space with a mixture of functions, like homes, services and infrastructures, with the aim of activating innovative processes over time within the community (Cruz 2008) and favouring the definition of a space of encounter between different urban situations.

The experiment belongs to the field of space for social action. For the project began with the physical and social situation and has tried to interpret and steer the forces and logics that are modifying the territory. In this particular case, we are dealing with a perspective involving actions limited to certain points or areas of intervention. Social action, not reasoning exclusively on the informal but on the relationship this has with the formal, is trying to recompose the city territory. Thus, new intermediate relational spaces are configured, embryos of vitality able to reconnect the formal-informal thread, as well as represent a point of encounter between two different but closely linked ways of structuring society. This connective space therefore has a therapeutic function, in that it fosters social exchange within the community in the direction of opening up to shared models of conceiving the city, without which the latter would lose its conversion potential aimed at creating forms of urbanity.

Informality and different approaches to space design

The analysis of the variety of directions in which urban reality is being projected forces us to identify instruments of analysis, knowledge and theorisation aimed at devising project-oriented methods able to offer suitable solutions for the complexity of spatial forms. Informal urban processes appear in this respect to be an important perspective from which to begin to reconfigure criteria and approaches connected with space design. Thus, in spite of the conceptual complexity, the diverse definitions and the tendency to contrast “formal” and “informal”, the importance taken on by this relationship shows itself capable of triggering a different way of conceiving space, at the same time assigning a perspective to future project-oriented action.

The density of situations that characterise the borders between formal and informal allows their interpretation in dichotomous terms to fall into the background, shifting the attention towards the area of interconnection between the two poles (McFarlane and Waibel 2016). The informal takes on a relation of a dialogical type with the formal, and contributes to reconfiguring the traditional situations no longer able to describe sufficiently the phenomena that arise in the contemporary city. In particular, this intermediate space (Maciocco and Tagliagambe 2009; Tagliagambe 2008) also represents the field of action of urban design, which extends its horizons in favour of knowledge neglected in city design but which proves essential for exploring different ways of conceiving of the space of inhabiting.

Design consequently takes on an important value as an instrument of knowledge. “To change in a non-procedural sense the character of the models and techniques for the construction of knowledge, means to surpass the procedural linearity of the relationship between knowledge and action and to target new horizons that honour the importance of project-based knowledge compared with analytical knowledge” (Maciocco 2005, p. 16).9

The importance of design is grasped in all its clarity precisely in the ability to intercept single and episodic phenomena, tendencies or behaviours and steer them towards processes able to transform the city of the present and direct the city of the future towards a development perspective. This project-based paradigm faces two features: the first, a component deriving from systematic, scientific, rigorous and formal processes, and the second, an approach recognised in informal phenomena characterised by continuous reconfigurations of socio-spatial relations and experiences. Understood as a driver of change, design is subject to a dual tension between the formal sphere of knowledge and the need to analyse and endorse reality in its many informal forms and dimensions. It organises itself in this wide intermediate space of action, and through continuous dialogical tension between formal and informal is projected towards different trends and approaches, an overall picture that is not final but in continuous evolution. For its programmatic capacity enables the compact network of relations to be developed and perspectives of change to be triggered in the sphere of transformation of the city. The interaction between formal and informal processes also produces different knowledge that contributes in turn to nurturing theoretical reflection.

Designing for intermediate spaces, between formal and informal, entails moreover the use of a different approach to the complexity of the city, characterised by its consideration of urban space as the place in which individual and collective practices can emerge (McFarlane 2012). However, this does not mean that design has to oppose individual and collective initiatives, even less that it should yield to them and take a non-propositional perspective. As has been highlighted, the formal sphere, within which we might also include design meant as a regulatory instrument, places itself in a dialogical relationship with informal processes and actions. Representing an essential moment of urban life, this relationship takes on great worth since innovative forms of creativity and action can emerge from it. For in the absence of this dialogical relationship no “creative capacity” could exist on the part of a collectivity (Lefebvre 1991). Precisely the importance of this concept summarises the value taken on by design at the border between formal and informal. Its non-episodic capacity makes the relationship established between these two spheres able to create a shared space that adapts itself to urban reality in continuous change.

From this viewpoint, planning and design methods relegate to the background rational-comprehensive positions that organise themselves through dichotomous categories and universally valid holistic approaches, and direct their gaze towards informal knowledge and micro-processes neglected by city design. It is a case of addressing design that, based on the awareness of the value taken on by the territory and its relations, develops as a structuring element from which to depart with the purpose of creating different perspectives in conceiving urban space. This plural approach, in contrast with a homogeneous view of the city, favours the success of diversity and alternative points of view. It therefore appears clear that design can be the instrument of knowledge able to cope with both the formal character and the informal one of the city. The tension that develops from the relations established between these spheres produces a different awareness, closely connected with action, which contributes to defining perspectives for the city.


Definitions taken from the Situationist International Bulletin, S.I.N° 1, June 1958 (Various Authors 1994).


Among the numerous projects exploring the theme of informality we wish to point out: that of the Bair Balliet group of designers which offers some suggestions for urban renewal in the city of Detroit; the study of the Brazilian favelas presented by Patricia Parinejad; a set of projects aiming to transform the life of the poorest rural communities in Chile; the proposal to introduce small structures into the traditional “hutong” of Peking by the Chinese architect Zhang Ke and the structuring of tactical constructions proposed by a group of Hong Kong architects (Various Authors 2016).


Our translation.


On this subject Ostrom (et al. 2006) suggests some principles to link the formal sphere with the informal: a system at various levels of government as an alternative to centralisation or total decentralisation; a balance between “formal” intervention and “informal” practices; made to measure interventions as regards the capacity of the structure; interventions that have various possible outcomes; verify whether formalisation is functioning by measuring up to what point people are willing to be part of the network.


Our translation.


Our translation.


The relation between formal and informal sphere is explored in the novel Texaco, which describes the way of life and the structuring of the spaces of the informal Creole city. Chamoiseau (1992) picks out the space between these two conditions as a border and hybridisation area, in which a series of relations are generated linked with industriousness, work, contacts and civil relationships. The relation between formal and informal is structured indeed on this continuous process of interaction between the two spheres.


The concept of state of exception proposed by Agamben (1995) is traced back to that of sovereignty. The power of the sovereign founds the law, but at the same time is excluded from its application. The state of exception is a process by which the sovereign suspends the validity of a law and to do so has to be outside the law himself. The exception is however always as regards the norm through the relation of exclusion that links the norm with its exception. According to Agamben, the line of exception may be traced back to a border space, an intermediate area between order and disorder, formal and informal, which is indeed the state of exception, through which chaos is included in the norm.


Our translation.



Authors’ information

Laura Lutzoni is a postdoctoral research fellow in Urban Planning at University of Sassari, Department of Architecture, Design & Urban Planning. Her present research focuses on the relationship between urban and architectural design and the transformations of the urban context determined by spatial and social processes that take place both within the city and the territory at large. Among her publications: Shopping as an Urban Leisure Activity (In: Maciocco G, Serreli S (Eds) Enhancing the City: New Perspectives for Tourism and Leisure. Springer-Verlag, Berlin, Heidelberg, New York, 2009), Temporary uses as a perspective of urban design (In: Maciocco G, Sanna G, Serreli S (Eds) The Urban Potential of External Territories. FrancoAngeli, Milano, 2011) and Spazi dell’acqua come luoghi dell’abitare. Il progetto della città di Olbia (Urbanistica Informazioni, 263, 2015).


The author would like to thank Giovanni Maciocco at University of Sassari for his helpful and constructive comments that greatly contributed to improving this work. A special thanks to Christine Tilley for her continued support in translating and proofreading this contribution.

Competing interests

The author declares that she has no competing interests.

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors’ Affiliations

Department of Architecture, Design & Urban Planning, University of Sassari


  1. Agamben G (1995) Homo sacer. Il potere sovrano e la nuda vita. Einaudi, TorinoGoogle Scholar
  2. Alsayyad N (2004) Urban Informality as ‘New’ Way of Life. In: Roy A, Alsayyad N (eds) urban informality: transnational perspectives from the Middle East, Latin America, and South Asia. Lexington Books, LanhamGoogle Scholar
  3. Appadurai A (2000) Grassroots globalization and research imagination. Public C 12:1–19View ArticleGoogle Scholar
  4. Bellanca N (2010) Una breve introduzione all’economia informale. Accessed 31 Aug 2016
  5. Benjamin W (1986) Parigi capitale del XIX secolo. Einaudi, TorinoGoogle Scholar
  6. Benjamin W (2010) I “passages” di Parigi. Einaudi, TorinoGoogle Scholar
  7. Bhabha HK (1994) The location of culture. Routledge, LondonGoogle Scholar
  8. Branzi A (2006) Modernità debole e diffusa Il mondo del progetto all’inizio del XXI secolo. Skira, MilanoGoogle Scholar
  9. Careri F (2001) Constant New Babylon, una città nomade. Testo & Immagine, TorinoGoogle Scholar
  10. Castells M, Portes A (1989) World underneath: the origins, dynamics and effects of the informal economy. In: Castells M, Portes A, Benton L (eds) The informal economy: studies in advanced and less developed countries. John Hopkins University Press, BaltimoreGoogle Scholar
  11. Castillo J (2001) Urbanisms of the informal transformations in the urban fringe of Mexico City. Praxis: J Writ Build 2(1):102–111Google Scholar
  12. Chamoiseau P (1992) Texaco. Éditions Gallimard, ParisGoogle Scholar
  13. Chen MA (2006) Rethinking the informal economy: linkages with the formal economy and the formal regulatory environment. In: Ostrom E, Guha-Khasnobis B, Kanbur R (eds) Linking the formal and informal economy. Oxford University Press, New YorkGoogle Scholar
  14. Chiodelli F (2009) La cittadinanza secondo Henri Lefebvre: urbana, attiva, a matrice spaziale. Territorio 51:103–109Google Scholar
  15. Coletto D (2010) L’economia informale nel sud del mondo fra dilemmi interpretativi e di azione. Accessed on 31 Aug 2016
  16. Cruz T (2008) De la frontière globale au quartier de frontière: pratiques d’empiètement. Multitudes 31(1):69–74Google Scholar
  17. Davis M (2006) Planet of slums. Verso, LondonGoogle Scholar
  18. De Certeau M (1984) The practice of everyday life. University of California Press, BerkeleyGoogle Scholar
  19. De Solà Morales M (1999) Progettare città. Quaderni di Lotus, 23
  20. De Soto H (1989) The other path: the invisible revolution in the third world. Harpercollins, New YorkGoogle Scholar
  21. De Soto H (2000) The mystery of capital: why capitalism triumphs in the west and fails everywhere else. Basic Books, New YorkGoogle Scholar
  22. Deleuze G, Guattari F (1980) Mille plateaux. Capitalisme et schizophrénie. Éditions de Minuit, ParisGoogle Scholar
  23. Foucault M (1969) L’archéologie du savoir. Gallimard, ParisGoogle Scholar
  24. Foucault M (1977) Microfisica del potere: interventi politici. Einaudi, TorinoGoogle Scholar
  25. Friedmann J (1987) Planning in the public domain: from knowledge to action. Princeton University Press, PrincetonGoogle Scholar
  26. Hernández F, Kellett P, Allen LK (eds) (2010) Rethinking the informal city: critical perspectives from Latin America. Berghahn books, New YorkGoogle Scholar
  27. Holmes B (2007) Do-It-Yourself Geopolitics – Map of the World Upside Down. In: AAVV Urban/act, aaa—PEPRAV, Paris. Accessed on 31 Aug 2016
  28. ILO (1972) Employment, income, and equality. A strategy for increasing productive employment in Kenya. ILO, GenevaGoogle Scholar
  29. Ingold T (2011) Being alive: essays on movement, knowledge and description. Routledge, New YorkGoogle Scholar
  30. Jacobs J (1961) The death and life of great American cities. Random House, TorontoGoogle Scholar
  31. Landry C (2006) The art of city making. Earthscan, LondonGoogle Scholar
  32. Lefaivre L (2007) Ground-up city play as a design tool. 010 Publisher, RotterdamGoogle Scholar
  33. Lefaivre L, Roode I, Fuchs RH (eds) (2002) Aldo van Eyck: the playgrounds and the city. NAi, RotterdamGoogle Scholar
  34. Lefebvre H (1991) The Production of Space. Blackwell, CambridgeGoogle Scholar
  35. Lerner J (2003) Acupuntura Urbana. Editora Record, Rio de JaneiroGoogle Scholar
  36. Maciocco G (2005) Modelli, tecniche e poetiche del computer. In: Cecchini A, Plaisant A (eds) Analisi e modelli per la pianificazione: teoria e pratica: lo stato dell’arte. FrancoAngeli, MilanoGoogle Scholar
  37. Maciocco G, Pittaluga P (eds) (2001) La città latente. Il progetto ambientale in aree di bordo. FrancoAngeli, Milano
  38. Maciocco G, Tagliagambe S (2009) People and space: new forms of interaction in the city project. Springer, BerlinView ArticleGoogle Scholar
  39. McFarlane C (2012) Rethinking informality: politics, crisis, and the city. Plan Theory Pract 13(1):89–108View ArticleGoogle Scholar
  40. McFarlane C, Waibel M (eds) (2016) Urban informalities: reflections on the formal and informal. Routledge, LondonGoogle Scholar
  41. Mehrotra R (2003) Static spaces, kinetic places. Public Space in the Mega City of Bombay. Cities and Market Conference, IFHP World Congress Vienna, 5–8 October 2003, Vienna
  42. Mehrotra R (2008) Between sanctioned and shadow order. In: Ruby I, Ruby A (eds) Urban trans formation. Ruby Press, BerlinGoogle Scholar
  43. Mehrotra R (2010) Foreword. In: Hernández F, Kellett P, Allen LK (eds) Rethinking the informal city: critical perspectives from Latin America. Berghahn books, New YorkGoogle Scholar
  44. Nuvolati G (2006) Lo sguardo vagabondo, Il flâneur e la città da Baudelaire ai postmoderni. Il Mulino, BolognaGoogle Scholar
  45. Olds K (2001) Practices for ‘Process Geographies’: a view from within and outside the periphery. Environ Plan D 19:127–136View ArticleGoogle Scholar
  46. Ostrom E, Guha-Khasnobis B, Kanbur R (2006) Beyond formality and informality. In: Ostrom E, Guha-Khasnobis B, Kanbur R (eds) Linking the formal and informal economy. Oxford University Press, New YorkGoogle Scholar
  47. Perulli P (2007) La città. La società europea nello spazio globale. Bruno Mondadori, MilanoGoogle Scholar
  48. Porter L (2011) Informality, the commons and the paradoxes for planning: concepts and debates for informality and planning. Plan Theory Pract 12(1):115–120View ArticleGoogle Scholar
  49. Portes A, Schauffler R (1993) Competing perspectives on the Latin American informal sector. Popul Dev Rev 19(1):33–60View ArticleGoogle Scholar
  50. Roy A (2005) Urban informality: toward an epistemology of planning. J Am Plan Assoc 71(2):147–158View ArticleGoogle Scholar
  51. Roy A (2009a) The 21st-century metropolis: new geographies of theory. Reg Stud 43(6):819–830View ArticleGoogle Scholar
  52. Roy A (2009b) Strangely familiar: planning and the worlds of insurgence and informality. Plan Theory 8(1):7–11View ArticleGoogle Scholar
  53. Roy A (2009c) Why India cannot plan its cities: informality, insurgence and the idiom of urbanization. Plan Theory 8(1):76–87View ArticleGoogle Scholar
  54. Roy A (2011) Slumdog cities: rethinking subaltern urbanism. Int J Urb Reg Res 35(2):223–238View ArticleGoogle Scholar
  55. Roy A, Alsayyad N (eds) (2004) Urban informality: transnational perspectives from the Middle East, Latin America, and South Asia. Lexington Books, LanhamGoogle Scholar
  56. Sadler S (1999) Thesituationist city. MIT Press, CambridgeGoogle Scholar
  57. Sassen S (1994) The informal economy: between new development and old regulation. Yale law J 103(8):2289–2304View ArticleGoogle Scholar
  58. Sassen S (2001) The city: between topographic representation and spatialized power projects. Art J 60(2):12–20View ArticleGoogle Scholar
  59. Sassen S (2005) Fragmented urban topographies and their underlying interconnections. In: Brillembourg A, Feireiss K, Klumpner H (eds) Informal city. Prestel Publishing, MunichGoogle Scholar
  60. Sassen S (2006) Territory, authority, rights: from medieval to global assemblages. Princeton University Press, PrincetonGoogle Scholar
  61. Saunders W (ed) (2008) Can designers improve life in non-formal cities? Harvard Design Magazine, 28
  62. Tagliagambe S (2008) Lo spazio intermedio. Università Bocconi Editore, MilanoGoogle Scholar
  63. Turner FC (1978) L’abitare autogestito. Jaca Book, MilanoGoogle Scholar
  64. Various Authors (1994) Internazionale Situazionista. Nautilus, TorinoGoogle Scholar
  65. Various Authors (2000) Mutations. Actar, BordeauxGoogle Scholar
  66. Various Authors (2016) La Biennale di Venezia. 15ª Mostra Internazionale di Architettura. Reporting from the front. Marsilio, VeneziaGoogle Scholar
  67. Wirth L (1938) Urbanism as a way of life. Am J Sociol 44(1):1–24View ArticleGoogle Scholar
  68. Yiftachel O (2009) Theoretical notes on ‘gray cities’: the coming of urban apartheid. Plan Theory 8(1):87–99View ArticleGoogle Scholar


© The Author(s) 2016