Beyond the professional–local knowledge dichotomy: Toward a new epistemology in urban planning

Introduction: Revisiting knowledge in urban planning

Planning has long been understood as a field ‘located precisely at the interface between knowledge and action’ (Friedmann and Hudson, 1974: 2). Exploring how knowledge gets translated into action has been ‘central to the concerns of planning theory’ (Campbell, 2012: 137), while plans themselves have been described as ‘a set of knowledge practices that physically construct a material reality’ (Tett and Wolfe, 1991: 199).

Since the 1960s, scholars have categorized the types of knowledge observed in planning processes in a binary way, as either ‘professional’ or ‘local’, with each type associated exclusively with specific actors. According to this approach, the former is held by professional planners, who acquire it through academic training and on-the-job experience, while the latter is gathered by lay people from everyday experience and familiarity with living environments (Corburn, 2003; Van Herzele, 2004). Much subsequent research has focused on power–knowledge relations (Foucault, 1980) between professional planners, whose ‘command of specialist knowledge’ (Rydin, 2007: 53) gives them an advantage in planning processes, and ordinary people, whose lay knowledge is generally undervalued (Fenster and Yacobi, 2005; Scott, 1998).

This article builds on the work of these scholars and others who described planning as a crucial field for citizen involvement and knowledge sharing (Rydin, 2007), and knowledge in planning as never objective (Healey, 1992b) and always connected to and shaped by power (Flyvbjerg, 1998; Forester, 1989). However, we challenge the binary distinction between professional and lay-local knowledges that is taken for granted in much of this literature, and argue that recent shifts in planning and society have led to the rise of new actors, discourse arenas and knowledge types that don’t fit neatly into this dichotomy – or, indeed, even conform to conventional definitions of knowledge.

These shifts include: (1) the emergence of a new neoliberal urban technocracy, which prioritizes specific types of growth-orientated knowledge in increasingly opaque ways (Raco et al., 2022; Savini and Raco, 2019); (2) the unprecedented popularization of planning knowledge and discourse via mass media coverage, social media, online platforms and data democratization (Giest et al., 2016; Margalit, 2022); and (3) the rise of alternative ways of knowing, ranging from populism to artificial intelligence (AI), which challenge the intersubjective nature of knowledge itself and impact its application in public life (Caprotti et al., 2024; Jha et al., 2021).

In this context, we contend that the widely cited professional–local knowledge dichotomy now hinders our understanding of contemporary knowledge and power–knowledge dynamics in planning, and that scholars should move beyond it and develop an updated and more nuanced epistemology. To make this concrete, we assemble a typology of contemporary knowledge types based on an extensive review of the literature on knowledge and planning. Instead of automatically associating specific knowledge types with specific actors, we use the analytical methods developed by Van Dijk (2003, 2012) and Fairclough (1989, 2003) to characterize them based on their discursive characteristics. Moreover, we show how planners, other professionals and laypeople now use varied knowledge types in a variety of discourse arenas, and discuss some of the questions this raises regarding power–knowledge relations between them.

Our work builds upon Rydin’s (2007: 54) observation that knowledge in planning is ‘inherently multiple, with multiple claims to representing reality and multiple ways of knowing’, and that it now has ‘a variety of sources and takes a variety of different forms’. Yet, as our typology shows, this multiplicity and variety have greatly increased in recent years. Neoliberal technocracy, for instance, has introduced new forms of expertise into planning, while knowledge popularization and widespread access to technical capabilities such as generative AI now allow non-professionals to wield various forms of professional and even technical knowledge, thus blurring the boundaries between ‘professional’ and ‘lay’ ways of knowing. We also elaborate on Davoudi’s (2015: 322) observation that in planning ‘the boundaries of knowledge are fluid and overlapping’, by showing how contemporary knowledge types can blend together and create novel, hybrid forms.

Our analysis adopts Rydin’s (2007: 58) suggestion that ‘the planning system should be conceptualized as a series of arenas in which a variety of knowledges engage with each other’. We show, however, that these knowledges are now deployed in an expanding variety of discourse arenas – both old and new, formal and informal. We do not argue that the well-established hierarchy between professional and lay arenas is completely obsolete, or that there is not some stability and fixity in them. Rather, we suggest that the current array of arenas constitute dynamic and ad-hoc ‘knowledge networks’ (Rydin, 2007: 52) in which a ‘system of meanings’ (Finlayson and Martin, 2006: 159) and relationships are constructed in new ways.

We conceptualize knowledge as the accumulated representations, assumptions and beliefs that people hold in their heads, which they use to interpret and express information (Fairclough, 1989; Rydin, 2007; Van Dijk, 2012). Epistemology is defined as the study of knowledge, what it means ‘to know’ and what knowledge is considered valid (Couper, 2020).

In the next section, we present some of the central scholarly debates over knowledge and power–knowledge relations in planning. We then briefly explore some of the trends observed in recent planning and social science research and their impacts on planning knowledge. Next, we present our updated typology of planning knowledges and their discursive characteristics, and conclude with a brief discussion of possible implications for power–knowledge dynamics in planning and with a call for planners and researchers to further develop the proposed framework.

Knowledge and power–knowledge relations in planning

The knowledge involved in planning processes, scholars have shown, is complex and multifaceted. It has proven notoriously difficult to define (Gunder, 2004), and goes by many names, including ‘evidence, information, expertise, data, facts, research, proof, statistics, interpretations, values, or intelligence’ (Campbell, 2012: 137). It is both descriptive and prescriptive, qualitative and quantitative, explicit and implicit, visual and textual, art and science (Friedmann, 1987; Gunder and Hillier, 2016; Innes, 1987; Schon, 1983; Soderstrom, 1996). It addresses physical built environments, as well as overlapping social and natural systems, and the interfaces between them (Sanchez, 2017).

Planning processes, according to the literature, draw upon professional expertise alongside lay knowledge (Carmon, 2013; Davoudi, 2009). Professional planners are ‘trained in conceiving, designing and implementing urban policies and plans’, which involve transformation of land uses, buildings and infrastructure (Moroni, 2020: 563). Their expertise is both distinct, that is, derived from specialized knowledge and know-how that is unique to planning, and inherently interdisciplinary, reflecting a multiplicity of actors and fields of expertise that are involved in planning (Carmon, 2013; Healey, 1992a). Local, ‘everyday’ or ‘ordinary’ knowledge, on the other hand, ‘does not owe its origin, testing, degree of verification, truth status, or currency to distinctive … professional techniques but rather to common sense, casual empiricism, or thoughtful speculation and analysis’ (Lindblom and Cohen, 1979: 12). It is based on lived experience and situated in specific geographical and cultural contexts (Geertz, 1983), reflects an intimate familiarity with living environments and is generally associated with lay individuals and communities (Corburn, 2003; Innes and Booher, 2010).

Modern professional planning knowledge, according to theorists, is not uniform and has taken on more and varied forms over time. The visionary planners of the early 20th century presented their reasoning as ‘scientific’ (Davoudi and Strange, 2009), while post-Second World War ‘rational’ planners professed to wield objective and universal knowledge (Friedmann, 1978). The theorists of the ‘communicative turn’ (Healey, 1992b) and the ‘interpretive tradition’ (Davoudi, 2012) followed Foucault (1980) in seeing knowledge and power–knowledge dynamics in planning as identity driven and politically inflected. The idea that planners’ knowledge can never truly be neutral or objective, but inevitably contains (conscious or unconscious) underlying assumptions and biases (Healey, 1992b), has become widely accepted.

Thus, while rational-scientific knowledge in many ways retains its dominant position (Davoudi, 2012), professional planning knowledge is now seen as encompassing multiple ways of knowing – including more systematized and positivist ‘hard’ knowledges and more interpretive ‘soft’ knowledges (Davoudi, 2012; Tamm Hallstrom, 2015). Healey (1992a: 17), for example, demonstrated how planners ‘operate across knowledge forms in their daily work’. These may include knowledge of the political dynamics that surround planning (Forester, 1989), tacit forms of understanding (Polanyi, 1966; Schon, 1983), knowledge of the personal and emotional aspects of planning (Baum, 2015; Innes, 1998), as well as practical judgement or ‘phronesis’ (Flyvbjerg, 2004).

Theorists have also pointed out a blind spot in the professional knowledge–action sequence: while the knowledge gathered by planners is descriptive, planning actions are prescriptive, and thus necessarily involve some form of normative judgement (Campbell, 2012). Others described knowledge and action in planning as ‘recursively interlinked’, rather than arrayed along ‘a linear, causal chain’ (Davoudi, 2015: 317).

Scholars have also consistently criticized professionalized planning for ignoring or excluding lay knowledge (Friedmann, 1973). Foucault (1980: 81) argued that popular forms of knowledge are often delegitimized or suppressed because they are produced outside of ‘established regimes of thought’, while Scott (1998) showed how professional knowledge can be imposed in place of local knowledge to facilitate greater centralization and control. Researchers have thus argued that local-lay knowledge is rarely ‘acknowledged as having any validity in the planning process’ (Sandercock, 1998: 63), and that planners perceive others’ ways of knowing as an epistemic threat to their status (Innes and Booher, 2010). Moreover, trained planners use inscrutable ‘exclusionary language’ to reinforce their power–knowledge advantage over non-planners (Weston and Weston, 2013), creating an ‘incredibly steep and energy sapping learning curve’ (Inch, 2015: 415) for laypeople who seek to learn their professional jargon (Fenster and Kulka, 2016).

To overcome this, scholars and practitioners have developed a range of tools and tactics to facilitate the expression of non-professional knowledge in planning processes (Kleinhans et al., 2015). In the process, planners have gone from being exclusive holders of knowledge to mediators and facilitators of ‘mutual understanding’ between various actors and knowledge types (Healey, 1992b: 240), while knowledge exchanges have become ‘a two-way transaction rather than one-way communication from expert to layman’ (Innes, 1987: 89).

Meanwhile, planning scholars from the Global South have increasingly challenged the universal application of knowledge produced in the Global North (Watson, 2009), arguing that ‘endogenous’ ways of knowing – or some combination of the two – are better suited to understanding and addressing urban realities in Southern contexts (Winkler, 2022).

While power–knowledge inequalities remain pervasive, theorists generally agree that contemporary planning processes must invariably contend with multiple knowledge types (Innes, 1987; Rydin, 2007). Yet, despite various attempts to create typologies of planning knowledges (see Alexander, 2005; Friedmann, 1987), much of planning theory and practice continues to relate to knowledge in a binary way, as either ‘professional’ or ‘local’ (Corburn, 2003; Van Herzele, 2004).

Planning in flux: New knowledge types, actors, arenas and epistemic challenges

We argue that in the years since the bulk of these debates took place, planning itself, along with the broader societal context in which it is embedded, has shifted in fundamental ways that necessitate a reassessment of the variety of knowledges involved in it. We focus on three major changes: the rise of new forms of technocratic expertise, the popularization of planning knowledge and the radical challenges to the very nature of knowledge itself posed by populism, AI and other epistemic trends.

First, professionalized planning has witnessed a pendulum shift in which highly systematized forms of growth-orientated knowledge and technical expertise have increasingly been ‘hierarchically imposed over other types of knowledges’ (Savini and Raco, 2019: 11). The expertise employed by this ‘new urban technocracy’ (Savini and Raco, 2019: 11) is composed of legal–contractual, technical, numerical and ‘hard’ knowledges (Tamm Hallstrom, 2015). In line with a broader trend observed in public policy discourse in the neoliberal era (Berman, 2022), economic reasoning has come to play a central role in planning processes (Layard, 2019). Planning rationales are now subordinated to quantitative housing targets and metrics (Raco et al., 2022), developer profitability calculations (Layard, 2019) and the logic of land valuations and public revenue maximization (Metzger and Zakhour, 2019). This has occurred in both the Global North and South, and in both liberal democracies and illiberal contexts – albeit to different extents (Savini and Raco, 2019).

In this new reality, planners have become ‘only one player among a broader spectrum of legitimate actors and stakeholders’ (Savini and Raco, 2019: 11), while their professional knowledge has been subordinated to that of starchitects, transnational design firms, ‘development engineers’, contract lawyers, accountants, appraisers, financiers, spreadsheet consultants, futurists and so on (Savini and Raco, 2019: 11). Likewise, the rise of ‘smart cities’ has centred the instrumental, positivist knowledges (Cook and Karvonen, 2024) wielded by actors such as chief innovation officers, data scientists, computer programmers, tech startups, philanthropists, user-interface designers and smart-city consultants (Kitchin et al., 2019). Tech corporations and entrepreneurs have taken on the role of planner and developer (Carr and Hesse, 2020), while plans are increasingly discussed in arenas such as hackathons, expos, corporate lobby groups, supra-national policy networks and advisory boards (Kitchin et al., 2019).

While ostensibly drawing on diverse disciplines, this trend has actually led to a standardization and homogenization of knowledge inputs, while suppressing ‘softer’ knowledges, including ‘less-necessary’ expertise and lay perspectives (Savini and Raco, 2019). Such narrowly technical, delivery-orientated knowledges place ‘less emphasis on the overarching meaning of the built environment or how a particular intervention will impact current and future residents’ (Cook and Karvonen, 2024: 374), while knowledge-generation and decision-making processes have been ‘black-boxed’ (Rydin et al., 2018) and depoliticized (Savini and Raco, 2019).

Second – and perhaps in response to the increasingly opaque nature of technocratic planning – a parallel process of knowledge popularization and democratization has occurred, with the realm of communicative planning expanding beyond regulatory and participatory frameworks. Media outlets, long seen as shaping public perceptions of planning issues (Forester, 1989), have greatly expanded their coverage of plans in recent years, with planners, developers and activists increasingly relying on mass media to reach large audiences (Fox and Margalit, 2024; Schweitzer and Stephenson, 2016). Social media networks and other online platforms constitute another informal arena for popularizing knowledge and engaging citizens (Kleinhans et al., 2015), including in non-democratic contexts (Gillespie and Nguyen, 2018). Likewise, open data portals, e-participation platforms and citizen-run websites enable knowledge sharing between citizens and planners, and among citizens (Giest et al., 2016; Rogers, 2016). Recent research describes processes of ‘knowledge co-production’ (Lall et al., 2023), in which multiple ways of knowing held by diverse networks of actors combine to create ‘mestizo knowledges’ (Cociña et al., 2023).

Thus, we argue, information on plans has increasingly become available to anyone with an internet connection, while new and diverse discourse arenas can, and often do, facilitate lively debates and the open exchange of information, thus enriching local knowledge and lay understandings of plans (Margalit, 2022). These arenas also have their limitations, such as the corporate media’s tendency to focus on marginal and symbolic aspects of plans, while reinforcing pre-existing power–knowledge hierarchies (Schweitzer and Stephenson, 2016). Moreover, they are still likely to foster epistemic injustice, with knowledge undervalued based on speakers’ marginalized identities (Fricker, 2007) – or overvalued (al-Gharbi, 2024), depending on the political–cultural context. It is also worth noting that greater availability of information, particularly online, does not necessarily lead to more widespread knowledge creation (Lynch, 2016).

Third, the very nature of knowledge in planning as a kind of intersubjective commons has been challenged from multiple directions. One such challenge comes from illiberal populist movements which, theorists argue, constitute distinct epistemic communities (Nawrocki, 2024) with their own sources of knowledge (Ylä-Anttila, 2018). These groups often exhibit extreme scepticism of and disdain for the epistemic authority of experts, including planners, who are perceived as unelected technocrats who serve elites (Fainstein and Novy, 2025; Sager, 2020). Populist movements often reject the shared knowledge of mainstream society and instead embrace ‘post-truth’, adopting ‘alternative facts’ and narratives (Bergmann, 2020). Research has shown how data democratization and social media, rather than combating these trends, have often helped spread false narratives (Flaherty et al., 2022).

In this context, scholars are also examining forms of not-knowing, such as denialism, that is, the motivated rejection of established empirical knowledge (Proctor and Schiebinger, 2008), agnotology, that is, the deliberate production of ignorance (Proctor and Schiebinger, 2008), and strategic ignorance, that is, the intentional avoidance of knowledge (McGoey, 2012). In some cases, non-knowledge can be seen as a greater source of power than knowledge itself (McGoey, 2012).

Another epistemic challenge is posed by the ‘algorithmic governance’ of cities (Smith, 2020), in which human knowledge is encoded into software (Kitchin, 2011) and often augmented by artificial intelligence (Peng et al., 2023), in order to automate urban processes (Cugurullo et al., 2024). Initial applications of this exist in the form of mobility and parking software (Nikitas et al., 2020), predictive models and generative AI design programmes (Peng et al., 2023), ‘smart’ neighbourhoods that continuously collect data from residents (Carr and Hesse, 2020) and ‘city brains’ (Cugurullo et al., 2024). While the implications of such still-evolving interventions are not yet well understood, their introduction of technical expertise from non-planning fields and non-human intelligence whose rationality is often opaque presents clear challenges to both professional and local knowledges.

While the processes described above are considered distinct and sometimes even contradictory, in planning, we argue, they are also interrelated. For instance, as knowledge becomes more democratized, experts may be tempted to retreat further behind the veil of technocracy and post-politics (Salter, 2016), and vice versa. Likewise, while emerging AI platforms are seen as an effective means of gathering local knowledge, they may also create further distance between planners and citizens by replacing direct human communication with impersonal, automated interactions (Cugurullo et al., 2024). Moreover, phenomena which are generally seen as mutually antagonistic – such as populism and technocracy (Salter, 2016) – have increasingly been observed to converge in unexpected ways, as recent scholarship on ‘technocratic populism’ (Bickerton and Accetti, 2021) suggests. Thus, technocratic knowledge is now popularized in ways that create ‘citizen-technocrats’ whose knowledge reflects professional understandings rather than local knowledge (Fox and Margalit, 2024).

Taken together, these developments herald fundamental shifts in the way that knowledge is produced, understood and communicated in contemporary planning. As Durning et al. (2010: 498) note, a political and social context in constant flux means that planners ‘are being constantly challenged as to what they know’. We argue that this new reality necessitates the development of a new epistemology in planning which broadens our conception of contemporary planning knowledge and its discursive expressions, and contributes to our understanding of the corresponding shifts in power–knowledge relations. Accordingly, in the next section we present a new typology of knowledge types in planning, based on an understanding of their discursive features rather than the identity of the knower.

An updated typology of knowledges in planning and their discursive representations

To compile our typology, we conducted a comprehensive review of the relevant theoretical and empirical academic research published in English since the 1960s that examined knowledge in the planning context, and identified a broad range of ways of knowing and expressing knowledge in planning (though by no means all). These were then organized into four distinct categories, each with their own set of common characteristics, which we detail below. These are loose categories and not meant to be seen as absolute. In cases where a knowledge type may be seen as belonging to more than one category, we have categorized it based on our interpretation of the literature.

Some types of knowledge mentioned in the literature have been consolidated or renamed for brevity and clarity. Some of the sources cited below represent the spiritual ‘mothers and fathers’ of these ideas, while others write about them from a distance or critique them. Most sources are from the planning literature, while research from the broader social sciences literature was drawn upon when this was seen as relevant to planning and helpful in further illuminating the ideas we discuss below.

To identify expressions of different knowledge types based on their discursive features, we draw upon Van Dijk’s (2003, 2012) work on knowledge and discourse, and critical discourse analysis methods developed by Fairclough (1989, 2003). Van Dijk (2012) argues that participants in discourses use their pre-existing knowledge resources to interpret new information and to frame statements and assertions. Framing ‘refers to a particular way of representing knowledge, interpreting problems, and providing an evaluative framework for judging how to act’ (Van Herzele, 2004: 198). Following Foucault, Fairclough (1989, 2003) focuses on the constitutive role of language in the dialectical relations between actors, texts and social structures, and on identifying how power influences how information gets framed. We thus suggest identifying and categorizing knowledge types in planning discourse by examining how various actors use knowledge to frame the information they express. In Table 1, and in the detailed descriptions of knowledge types below, we elaborate on the discursive features of each knowledge type.

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Table 1.

A typology of knowledges and their discursive characteristics in contemporary planning.

Category	Knowledge type	Definition	Discursive characteristics
I	Digital – automated	Computer-mediated or -generated (AI) knowledge, based on aggregation and codification of mass data	Concepts drawn from tech world, distils processes into rules and codes, excludes the un-codable, opaque or invisible
	Neoliberal technocratic	Growth-orientated forms of expertise, often legal, technical and quantitative; focus on efficient delivery	Emphasis on technical and quantitative aspects, reductive and compartmentalized logics, use of simplistic abstractions
	Rational – scientific	Applied reason guided by instrumental rationality and a utilitarian concern for progress and the public good	Presented as an objective, empirical, value-neutral, factual basis for policymaking; elides questions of power
	Technical	Specialized know-how or ‘techne’; familiarity with the formal tools, methods and language of planning	Universal and standardized, formalized, precise, a-contextual, impersonal, action-orientated, instrumental, applied in practice
	Procedural	Understanding of how statutory, administrative, political and other processes work and interact	Highlights key events and milestones, familiarity with key players and rules, focus on navigation of complex processes
II	Trans-disciplinary	Synthesis of planning knowledge(s) and other specialized disciplinary knowledges	Result of collaboration, negotiation, overlap and interface between different fields and ways of understanding
	Political	Deep understanding of power relations, hidden logics and interests of political actors, and how these affect plans	Appreciation of institutional constraints, political sensitivities, art of the possible, winners/losers, inclusion/exclusion
	Predictive	Grasp of complex interactions between status quo, planning interventions, social processes and outcomes	Systematic examination of different scenarios and their implications, acknowledgement of contingency and uncertainty
	Normative – theoretical	Relates to desired future states, based on value rationality and an informed grasp of possibilities	Prescriptive, subjective, value-laden, self-consciously political; marshals theories, models and best practices
	Narrative	Ability to construct coherent and compelling stories around planning actions; storytelling	Performative, persuasive, use of dramatic structure, expressive and evocative language, colour and irony, humour
	Empathic – emotional	People skills and emotional intelligence, ability to see and hear others, including unstated views and concerns	Concern for subjective perceptions and emotional states, may be expressed symbolically or non-verbally
	Visual – aesthetic	Ability to construct and/or interpret spatial representations, use them to communicate ideas	Presented in graphic formats such as maps, 3D models and renderings, and in textual interpretations of them
	Reflexive	(Self-)awareness of unconscious or unacknowledged biases that flow from personal habitus or social capital	Rejects assumptions about neutrality and objectivity, examines actors’ socio-economic and cultural backgrounds
	Tacit/phronesis	Practical, embodied judgement and ethics based on experience, wisdom, insight, intuition, creativity	Uncodified, embodied in actions, context-dependent; conveyed through practice, observation, imitation
	Ethnographic	Systematized representations of lay, place-based knowledge, produced through study and documentation	Approaches local/situated knowledge as raw data, uses scientific tools to analyse and interpret it
III	Local – experiential	Situated, place-based everyday knowledge, shared know-how and meanings	Highlights first-hand observation and lived experience; context-specific, uncodified, problem-solving orientation
	Indigenous	Folk knowledge based on intimate familiarity with natural environments and continual observation	Passed down over time, expressed through doing; holistic, integrates spiritual aspects and values; non-anthropocentric
	Popularized	Popular representations of specialized knowledge; may reflect alternative interpretations	Translates specialized knowledge into colloquial language; uses explanations, examples, metaphors to convey meanings
IV	Particularist	Selective, self-interested knowledge regarding the impacts of policy decisions on private interests	Concern for private gain over public good, rejection of universalist knowledge, experts seen as interest group
	Real rationality	Knowledge produced or manipulated to justify powerful interests and predetermined goals	Support of decisions ex post facto, ‘unhelpful’ claims ignored or suppressed, resistant to transparent debate
	Populist	Alternative way of knowing based on post-truth, rejection of expert knowledge, ‘common sense’	Simplistic, emotional and exaggerated formulations; claims to speak for imagined collective; promotes conspiracy theories

Conclusion

In his work on power-knowledge, Foucault (1980: 82) distinguished between dominant forms of knowledge in societies and subjugated forms, such as ‘local popular knowledges’. Scott (1998) applied this binary view of knowledge to the modern state, while planning scholars (Corburn, 2003; Friedmann, 1973) applied it to planning. Some theorists (Davoudi, 2012; Innes, 1987) further subdivided professional planning knowledge into an additional binary: positivist and interpretive. Theorists of the ‘communicative turn’ (Healey, 1992a; Sandercock, 1998) argued that ‘knowledge is inherently multiple’ (Rydin, 2007: 54). Within this multiplicity, however, scholars largely maintained the distinction between professional and lay-local knowledge, while power-knowledge critiques primarily addressed dynamics between professionals and lay actors.

In this article, we have sought to build upon this scholarship, while departing from the professional–local knowledge dichotomy. We have argued that due to major shifts in technology, media, society and planning itself, this dichotomy now limits our understanding of contemporary knowledge and power–knowledge dynamics. Instead, we have proposed a method of defining and classifying these multiple ways of knowing by their discursive expressions, rather than by the identity of the knower.

We have compiled these knowledges – as well as several distinct, recently identified knowledge types – into an updated typology, and explored how various professionals (planners and non-planners) and lay actors wield them in contemporary arenas. We demonstrated how contemporary ways of knowing are vastly more varied than the oft-cited professional–local knowledge dichotomy would imply, and showed how knowledge types can no longer be exclusively associated with specific actors, and in some cases even merge and combine to create novel hybrids.

Our approach introduces additional layers of nuance and complexity into long-standing critiques of power–knowledge conflicts between planners and laypeople (Friedmann, 1973; Sandercock, 1998) and raises new questions. For instance, how might conceptions of epistemic injustice (Fricker, 2007) change in a world in which ostensibly disempowered lay actors can now empower themselves with various forms of professional knowledge? Additionally, how might knowledges based on post-truth present new openings for upending entrenched power–knowledge hierarchies?

Moreover, the convergence of phenomena such as populism and generative AI presages new challenges to established planning knowledge, and to planners’ epistemic authority. Just as, under modernism, lay-local knowledges were suppressed in favour of professional knowledge (Scott, 1998), and neoliberalism devalued ‘interpretive’ and ‘soft’ knowledges in favour of technocratic pro-growth knowledges (Savini and Raco, 2019), the combined forces of illiberal populism and AI (wielded by Big Tech) may seek to render human planning knowledge superfluous altogether through automation. How might this impact our capacity for agency and collective action, for example, in the face of the Anthropocene polycrisis?

To conclude, we hope that this work will contribute to a more nuanced and up-to-date epistemology in urban planning. By challenging long-standing assumptions, we seek to inspire a renewed debate on knowledge and power–knowledge relations in contemporary planning. We also hypothesize that such power–knowledge dynamics will vary by geographical, demographic, socio-economic and political contexts. We hope this approach will continue to be refined in future research and debates on power–knowledge relations among planners, other professionals, laypeople and additional actors in a changing world. We believe such work would not only improve our understanding of knowledge in planning but also potentially improve how that knowledge is communicated in planning discourses.