A typology of social entrepreneurs in bottom-up urban development

The emergence of organic planning practices in the Netherlands introduces new, non-conventional, local actors initiating bottom-up urban developments. Dissatisfied with conventional practices and using opportunities during the 2008 financial crisis, these actors aim to create social value, thus challenging prevailing institutions. Intrigued by such actors becoming more present and influential in urban planning and development processes, we aim to identify who they are. We use social entrepreneurship and niche formation theories to analyse and identify three types of social entrepreneurs. The first are early pioneers, adopting roles of a developer and end-user, but lacking position and power to realize goals. Secondly, by acting as boundary spanners and niche en- trepreneurs, they evolve towards consolidated third sector organizations in the position to realize developments. A third type are intermediate agents facilitating developments as boundary spanners and policy entrepreneurs, without pursuing urban development themselves but aiming at realizing broader policy goals. Our general typology provides a rich picture of actors involved in bottom-up urban developments by applying theories from domains of innovation management and business transition management to urban planning and development studies. It shows that the social entrepreneurs in bottom-up urban development can be considered the result of social innovation, but this social innovation is set within a neoliberal context, and in many cases passively or actively conditioned by states and markets.


Introduction
Recent years have shown an upsurge of alternative, nonconventional practices in Dutch urban planning and development, in the national discourse often referred to as 'organic' urban development (Buitelaar et al., 2012;Buitelaar et al., 2014;Buitelaar, Grommen, & Van der Krabben, 2018;Buitelaar & Bregman, 2016;Rauws & de Roo, 2016;van Karnenbeek & Janssen-Jansen, 2018). These practices focus on incremental transformations of the existing urban fabric by purposefully allowing the 'unplanned' to emerge, mostly within the confines of an overall vision. As such, creating 'room' and opportunity for spontaneity and self-organization are eminently part of these practices. Buitelaar et al. (2018) state that the attention towards 'organic' planning approaches, spontaneity and self-organization can be found throughout other developed countries, referring to e.g. Moroni (2015). The incremental (i.e. process-related) aspect of the Dutch organic approach resembles what is more generally known in the international discourse as incremental planning (Brooks, 2002;Taylor, 1998).
A characterizing aspect of the organic planning approach is a change of actors involved (Buitelaar et al., 2012); smaller collectives or individuals originating from civil society join the 'playing field' of larger, professional actors (e.g. real estate developers, planning authorities, housing associations etc.). Buitelaar et al. (2012) provide a first general overview of both conventional and non-conventional groups of actors involved in organic urban development, but do not provide a more thorough analysis. Other scholars mostly reflect on incremental practices from the perspective of planners' roles and do not -or only scarcely -address the roles of the newcomers in the often lengthy processes (Brooks, 2002;Buitelaar et al., 2012;Taylor, 1998). Our first explorative observations confirm a role of individuals or small collectives within larger organic developments, initiating small-scale projects from the 'bottom-up' by means of self-organization (Boonstra & Boelens, 2011;Edelenbos et al., 2018;Moroni, 2015;Portugali, 2000). Such smaller bottom-up development initiatives function as starting points of -or catalysts within -larger organic developments plans by instigating changes in the identity of an area or drawing attention of other actors to an area as a result of place-making activities (Strydom et al., 2018). We also perceive initiators encountering various barriers, assumingly caused by frictions or conflicts with prevailing institutions. Differences can be identified with earlier bottom-up urban practices that originated from activism or the squatters' movement, of which Christiania in Copenhagen (Coppola & Vanolo, 2015) is a well-known historic example. In contemporary bottom-up practices we seek to analyse entrepreneurial endeavors aiming for broader social impacts by deliberately seeking collaboration with various (conventional) actors connections with the surrounding neighborhoods. We assume such bottomup endeavors to play an increased substantial role within established development practices, with governmental planning agencies recognizing, valuing and even consciously encouraging such practices. Furthermore, various scholars emphasize the relevance of bottom-up initiatives as they spur urban dynamics and innovation (Partanen, 2015).
Despite the assumed importance, however, little scientific knowledge and a thorough understanding of such bottom-up urban development processes is available, in particular who the actors involved in such practices exactly are. Too often and easily are such actors regarded as the mere community or civil society, similar to observations from Avelino and Wittmayer (2016) in the context of sustainability transitions. Therefore, this paper aims to provide a more substantiated typology of social entrepreneurs in bottom-up urban developments by analysing and comparing various non-conventional actor initiatives. A more profound understanding of this group is of relevance given their more emphatic manifestation, and can spur more effective (incremental) planning strategies as well as supporting the implementation of policies regarding active citizenship and innovation.

Contextualizing and positioning bottom-up initiatives in urban development
Before the emergence of organic planning practices in the Netherlands, more 'conventional' Dutch practices were generally characterized by large-scale 'blueprinted' planning and urban expansions, which align with theoretical notions of rational-comprehensive planning (Brooks, 2002;Taylor, 1998). Such conventional practices in the Netherlands had been typically state-led until roughly the 1990s, after which they became driven by public-private partnerships and more market-led practices under influence of decentralized urban areafocused governance approaches (Heurkens, 2012). Previously, we mentioned the relationship between the processes of recent Dutch organic planning practices and incremental planning theory, which stands in contrast to the abovementioned conventional practice which resemble the principles of rational-comprehensive planning practices and theories (Brooks, 2002;Taylor, 1998).
However, it should be noted that the theoretical distinctions between both planning paradigms (i.e. rational-comprehensive versus incremental) can be disputed. Amongst others van Karnenbeek and Janssen-Jansen (2018) argue that Dutch planning practice has always been more incremental than generally assumed, due to the informal interactions between planners, decision-makers and stakeholders preceding the formal decisions. The writings of Lindblom confirm this view in the broader international context, since he brought the incremental approach to the attention in the 1950s already, focussing on processes of decision-making in policy development (Lindblom, 1959). Aside from the more theoretical considerations, usage of the term 'organic' in Dutch urban planning practice mostly reflects a general approach that is less 'planned' and less fixated on predefined end results as was common beforehand.
The emergence of organic planning practices in the Netherlands more or less coincided with the financial crisis -roughly from 2008 to 2016 -and can be attributed to an absence of investment power for conventional developments. We found that the organic approach towards urban development during this crisis, together with a growing citizens' dissatisfaction with the outcomes of conventional practices (van den Berg, 2013) shaped the opportunities and motives for small bottom-up initiatives by non-conventional actors to emerge in the Netherlands. Moreover, we assume simultaneous developments such as the rise of the network society (Castells, 1996;Hajer, 2011) and policies addressing the potential capacity of society (Bussemaker & Schultz van Hagen, 2016) to have been of influence. The aforementioned combination of factors spurs civil society to engage in domains that were beforehand government-led or market-led. In other words: these factors offered 'room' for specific individuals and groups to take action and address societal needs that were apparently not sufficiently met by conventional actors. EU policies use the broader term of 'social innovation' for various novel initiatives in which citizens and organizations address societal challenges (Boonstra, 2015;Moulaert, MacCallum, & Mehmood, 2013). Such bottom-up developments are not limited to the Dutch context; similar developments emerge in other Western European countries (Colomb, 2012;Healey, 2015) and comparisons can be made with the concepts of grassroot initiatives (Peterman, 2000) and do-ityourself urbanism (Deslandes, 2013;Finn, 2014;Iveson, 2013).
In order to position our research and to clarify our perspective, we shed a light on the interpretations and implications of the terminology we use, starting with the dichotomy between 'bottom-up' and 'topdown'. In general, we perceive top-down approaches as characterized by a hierarchical imposition of plans on civil society in terms of government-and/or market-led development strategies. Given this consideration, the opposite -bottom-up approaches -are characterized by a spontaneous emergence, independent from governmental interference or state imposition. Few scholars and professionals in the domain of spatial planning specifically elaborate on the term bottom-up. Van den Berg (2013) refers to the various interests involved in spatial projects (e. g. land ownership, policies, land-use plans and complex legislation), which are hard to fathom for relative outsiders other than conventional actors. Therefore, initiators of bottom-up developments are forced to 'find their way up' in order to realize their goals. The term bottom-up vigorously expresses this movement or change upwards.
In the scientific field of transition management -and applied to sustainability transitions -Avelino and Wittmayer (2016) perceive such shifting power relations or this empowerment from a Multi-actor Perspective and relate it to the roles, relationships and positions of actors. Houterman and Hulsbergen (2005) address the term bottom-up from the perspective of the motivation of initiators, stating that they aim to improve the physical, economic and social conditions of their own living environment. In line with this, before, we direct our analyses towards initiatives that aim to generate social value -contrary to more commercially driven initiativesthus following recent attention for, and current debates on, such initiatives (Healey, 2015). Other useful connotations of the dichotomy between bottom-up and top-down beyond the mere state-society relationship are provided by scholars outside the western-European context in terms of distinctions in informality and formality and planned versus unplanned (Smith, 2014;Tian, Ge, & Li, 2017).
Bottom-up urban developments can be associated with the concept of citizens' initiatives, the highest participation level in models of citizens' participation (Arnstein, 1969;van Dam, Salverda, During, & Duineveld, 2014;van Houwelingen et al., 2014). Such models generally measure levels or degrees of involvement by the power granted to citizens (e.g. their decision-making authority) or the roles they adopt in processes. In general, successful citizens' initiatives originate from the community or civil society and establish themselves as formalized third-sector organizations by means of self-organization over time (Boonstra & Boelens, 2011;Edelenbos et al., 2018;Moroni, 2015;Portugali, 2000). Our first explorations of bottom-up urban developments have shown, however, that the key-persons involved are oftentimesaside from citizensabove all individual independent professionals. We therefore regard bottom-up urban developments as a specific category of citizens' initiatives and state that the actors involved find their origin at the interface of different private sectors, i.e. their characteristics are hybrid. Brandsen & Karré, 2011 use the term 'hybrid' to indicate actors mixing characteristics of state, market and civil society. This definition also applies to our study, with the limitation that the actors subject to our study combine characteristics of the civil society and market. The right side of Fig. 1 visualizes this hybridity in the origin of actors in bottom-up urban developments, by using an adapted version of the triangle of the welfare mix (Brandsen et al., 2005;Pestoff, 1992); the left side of Fig. 1 shows how citizens' initiatives are regarded in general, using the same triangle. We further substantiate this viewpoint of positioning the actors involved in bottom-up urban development by referring to Avelino and Wittmayer (2016), who argue that there is a problematic tendency of regarding everything that is not clearly market nor state as the civil society. We purposefully choose to speak of bottom-up initiatives instead of citizens' initiatives hereafter, given the multiple connotations as discussed. The right side of Fig. 1 illustrates the starting point of our endeavor: the diffuse characteristics of the actors involved, which we aim to unravel.

Theoretical underpinnings and analytical framework
Elaborating on the aim to create social value, we found a theoretical basis for our analyses in the concept of social entrepreneurship (Certo & Miller, 2008;Weerawardena & Mort, 2006). We perceive the initiatives subject to our analyses as social entrepreneurial activities, characterized by the recognition of opportunities and acting upon them with the aim of generating social value, i.e. fulfilling the needs of society (Austin et al., 2012;Certo & Miller, 2008). Social entrepreneurship differs from commercial entrepreneurship by its primary goal: the creation of social value versus financial value. Austin et al. (2012) refer to the so-called Social-Value Proposition (SVP), which embodies the motivation of our human subjects.
In comparing social entrepreneurship to commercial entrepreneurship, Austin et al. (2012) reveal specific barriers that social entrepreneurs encounter and actions and strategies needed to overcome them. Whereas commercial entrepreneurs often have access to both human and financial resources, social entrepreneurs experience difficulties in obtaining resources and are faced with laborious efforts to overcome this. Austin et al. (2012) list a number of constraints, such as: "limited access to the best talent; fewer financial institutions, instruments and resources; and scarce unrestricted funding and inherent strategic rigidities, which hinder their ability to mobilize and deploy resources to achieve the organization's ambitious goals" (Austin et al., 2012, p 377).
It is therefore crucial for social entrepreneurs to build: "a large network of strong supporters, and an ability to communicate the impact of the venture's work to leverage resources outside organizational boundaries" (Austin et al., 2012, p 377). This is amongst others deemed to depend on aspects of trust and reputation, mainly due to fundamental differences in the measurability of proposed values between commercial and social ventures (i.e. social returns are more complex, if not impossible to measure) (Austin et al., 2012). Since the actions and strategies to overcome barriers directly address the skills, competences and role fulfilment of the social entrepreneurs, they co-determine who our human subjects are and what characterizes them.
Additional theory that helps us better understand and position our human subjects is Strategic Niche Management (SNM) (Pesch, Vernay, van Bueren, & Pandis Iverot, 2017;Schot & Geels, 2008). We build on the perception that social entrepreneurs in urban development create an environment or habitat in terms of a social network, resources and support, that allows them to reach their goals, similar to niche formation in socio-technical innovations (Pesch, Vernay, van Bueren, & Pandis Iverot, 2017;Smith, Hargreaves, Hielscher, Martiskainen, & Seyfang, 2016). I.e. bottom-up urban developments thrive by protected environments where one can experiment, innovations can be tested and matured and which are relatively sheltered from market mechanisms, referring to the dichotomy between niches and regimes (Avelino & Wittmayer, 2016;Schot & Geels, 2008) and parallel to what we consider non-conventional practices and conventional practices in urban development. If we oversee the core processes of SNM, two new processes can be identified in addition to those already identified above in social entrepreneurship. One concerns the articulation and adjustment of expectations or visions, which guides an initiative in a certain desired direction. The other is learning processes on various dimensions (Pesch, Vernay, van Bueren, & Pandis Iverot, 2017), which we relate to organizational issues, business models, regulations and government policies, as part of enumerations of dimensions by Schot and Geels (2008) and Pesch, Vernay, van Bueren, & Pandis Iverot, 2017. Similar to successful social entrepreneurship, we assume processes of successfully establishing a niche to be dependent on our human subjects and what characterizes them, therefore of relevance to our analyses.
Nonetheless, the assumptions of the novelty and the merits of bottom-up urban development, compared to conventional top-down development, as acknowledged by many authors, we need to be critical about the distinct aspects and include potentially contradictory evidence in our analyses. Rabbiosi (2016) found that bottom-up initiatives tend to respond to conventional and often neoliberal approaches ambiguously. She states that such initiatives "challenge it, but at the same time they are consistent with its logic (p. 832)". She concludes that urban regeneration 'from the bottom up' suggests that the "urban civic substratum of contemporary cities" is the driver. However, this must be contended a basic irrefutable assumption while bottom up development, in the same manner as conventional development, are inseparably encapsulated and necessarily follow the same regulations, conditions and contextual prearrangements of society and governance shaped and developed over the last decades. Moulaert et al. (2007) also compared neoliberal and social innovation discourses about urban development, including associated policies and key agencies. They sought how social innovation, such as bottom-up development, can be a "potentially powerful concept, capable of anchoring urban change movements more firmly into the local social and political fabric (p. 195)". In this view bottom-up development is not necessarily seen as a separate, more ethical nor novel opponent to conventional approaches of urban development, but rather a 'third way' reconciling both. Following these critical notes in literature, we will test the merits of bottom-up urban development and confront the two ends of the spectrum, with bottom-up urban development as expression of neoliberalism or of social innovation, and seek for potential complementarity of both. Fig. 2 shows the framework for the analysis in this article. It addresses our human subjects, the newcomers in urban development projects, and their motives in the WHO & WHY variable; the actions and strategies to overcome barriers and reach goals are addressed by the HOW variable. Both variables have been operationalized in four parameters each, by building on the abovementioned theories. We will further explicate this operationalization later in this section. Fig. 2 is an elaboration of a conceptual framework we developed for analysing processes of bottom-up urban developments, consisting of two more variables (the WHAT and the CONTEXT).
The model is partly based on the framework for institutional analysis by Ostrom (2005), which is recognizable by the presence of the so-called action arena, which in this case only shows one particular group of actors, i.e. social entrepreneurs, given the focus of this article. The model also encloses elements of Healey's consolidated model of the development process, being 1) the roles in production, 2) the events in the development process and 3) the products and impacts or outputs and outcomes (Healey, 1992). As explained before, the focus within this article is on the WHO & WHY variable, but since the actions the actors deploy (the HOW) will be of relevance for drawing our typology, this variable is also addressed (i.e. operationalized in Fig. 2). Although the other two variables of the model are less relevant for the analysis in this article, Fig. 2 illustrates how all four variables are related. Of relevance therein is the iterative character of the processesinherent to incremental developmentexpressed by the connection (i.e. arrow) from the dependent WHAT variable back to the explanatory variables of the action arena, in successive rounds of decision making (Teisman, 2000).
Concerning the first parameter of the WHO & WHY variable, i.e. the characteristics, we will distinguish individual from organizational actors and determine in which sector to position them, referring to the levels of aggregation by Avelino and Wittmayer (2016) and Fig. 1. We also assumeand will identifya related difference in formality. In case of individuals, we are interested in their professional background and experience; in case of organizations, we are interested in the type of organization (i.e. legal entity) and the people operating within it. With regard to the second parameter of the motives and aims, we are emphatically interested in the way the Social Value Proposition (SVP) (Austin et al., 2012) manifests itself, since this aspect is central to the theory of social entrepreneurship we adopted.
Considering the third parameter roles, we distinguish primary from secondary roles. The primary roles relate to the development process itself and are a direct result of the actors' aims. Drawing from Healey's analysis of agency models (Healey, 1991), these roles include e.g. the developer and end-user in case of the initiators, whereas roles of others involved (i.e. strategic relationships) can include e.g. the landowner, financier, regulator or builder. We consider secondary roles to be adopted by social entrepreneurs because of the actions and strategies needed to overcome barriers and to create a niche. A first possible secondary role is that of the boundary spanner (Williams, 2002), to be perceived as an actor who is skilled in establishing cross-sectoral collaborations, 'bridging' different interests, negotiating and establishing trust within a network (Williams, 2002). Secondly, we are interested in niche entrepreneurs (Pesch, Vernay, van Bueren, & Pandis Iverot, 2017), which is evident given our combined theoretical approaches (i.e. niche formation and social entrepreneurship). We perceive such an actor as one actively deploying the earlier mentioned strategies of SNM, thus successfully creating a niche. Lastly, given relationships of bottom-up initiatives with governmental policies (e.g. active citizenship, social innovation), we are interested in possible roles of policy entrepreneurs (Kingdon, 2011), to be understood as actors drawing attention to certain issues or problems (i.e. agenda-setting) and actively and strategically connecting these problems to policies within political contexts (Kingdon, 2011;Pesch, Vernay, van Bueren, & Pandis Iverot, 2017). The theoretical notions of the three secondary roles find their origin at different scientific domains. We assume them to reflect the multiple behavioural aspects and versatile skills of social entrepreneurs in urban development. We therefore transpose them to our specific field of interest, bring them together, and give new meaning to the understanding of our actors of interest as such. Noteworthy is the fact that literature underlines the specific roles of individual agency therein (Kingdon, 2011;Pesch, Vernay, van Bueren, & Pandis Iverot, 2017;Williams, 2002).
The fourth parameter of the position and power is related to the establishment of strategic relationships -based on trust and reputationwhich bring forth the resources to realize goals, thus empowering the actor; Enserink (2010) refers to actors having 'realizing power' as such. In other words, the power of an actor depends on the resources available, which we assume depends on the position in a network. The aspect of trust knows many relevant, but complex facets regarding interpersonal relationships (Pennink, 2017). However, in the context of our study we also relate trust to an actor being a legal entity or not, since legal entities entail basic certainties, thus providing trust. Therefore, there is an inherent difference in the position of e.g. informally operating individuals as compared to formalized organizations. Since this draws back to the first parameter of the characteristics of actors, it exemplifies the interrelationship between the various parameters and why they cannot be regarded in an isolated manner.
The HOW variable in Fig. 2 consists of another four parametersrepresenting the actions and strategies deployed by social entrepreneurs, which are a combined result of the theoretical concepts we explored. The parameter of mobilizing resources stems from the concept of social entrepreneurship; the parameter of alignment and articulation and the parameter of learning processes stem directly from niche formation. The parameter of building social networks is a key aspect of both. Importantly to mention is the interdependency between the HOW variables and WHO variables; i.e. actions and strategies mainly determine which secondary roles the social entrepreneurs adopt, which in turn results in a certain position and power after successive 'rounds', in case of successful actions and strategies. Therefore, we will only identify which actions and strategies actors deploy in general -to determine their rolesand do not pursue an in-depth analysis of the activities themselves here, given the focus of this article.

Research method and case selection
Given the explorative, qualitative character of our research and the focus on a complex, contemporary phenomenon, we used a multiple case study approach for data-collection and analyses (Yin, 2014). The main units of analysis (i.e. cases) are areas in which we identified and studied social entrepreneurs and their general activities. We also studied the rich, complex contexts and other actors involved, thus providing a richer picture and deepening our understanding. Data collection focussed on document studies and semi-structured interviews.
We confined our case selection to the Dutch institutional context, to ensure a certain homogeneity. We further confined ourselves to developments at former, inner city industrial areas, given the observation that such areas function as prominent breeding grounds for bottom-up development initiatives. This can be attributed to the deindustrialization of western cities and growth towards knowledgebased economies, resulting in vacant and unused areas (i.e. brownfields or wastelands) which are often unattractive, too complex or risk bearing to be developed by conventional actors. Bottom-up initiators however perceive such areas as possible opportunities for realizing their goals. Moreover, many such areas are currently undergoing major transformative changes and we consider them illustrative for the urban dynamics we pursue to analyse. Anticipating our analyses, we remark that actors from the creative industry (Stam, de Jong, & Marlet, 2008) seem to play a major role within such developments, in line with findings of various scholars studying relationships between settlements of actors from the creative industry and urban development (Gregory, 2016;Hagoort et al., 2012).
In addition to the aforementioned criteria, considerations that are more pragmatic also played a role in selecting cases, such as the accessibility of data.
The first case we selected is the (former) industrial area Werkspoorkwartier (WSK hereafter) in the Dutch city of Utrecht; the second case is De Ceuvel in Amsterdam, which is part of the (former) industrial area Buiksloterham (BSH hereafter). Within the analyses of De Ceuvel we broadened our view towards the larger BSH area if related to De Ceuvel. We conducted the case study of WSK from October 2018 to April 2019. It comprised of a document study and 12 in-depth, semi-structured interviews with 14 stakeholders in WSK, varying from initiators of bottom-up developments (i.e. Hof van Cartesius and De Nijverheid; see below) to governmental actors, representatives of the joint association of businesses in the area, more conventional real estate developers and others. Furthermore, we attended various network meetings. The interviews were recorded, transcribed and analysed by selective and open coding using ATLAS.ti software; further analysis included e.g. a multiactor analyses (Enserink, 2010).
The case study of the Ceuvel was based on the analyses of both primary data and secondary data. The primary data included four semistructured interviews that we conducted at the end of 2019 and beginning of 2020. Two of which were with some of the early initiators of De Ceuvel -both architects -and two were with civil servants directly involved. The secondary data was retrieved from a study in 2017 on Urban Living Labs in which both De Ceuvel and BSH were cases, executed by two fellow researchers (Steen & van Bueren, 2017a;Steen & van Bueren, 2017b), one of whom is co-author of this paper. This data includes e.g. semi-structured in-depth interviews with two other members of the initiating team of De Ceuvel, i.e. the founder of Metabolic -a start-up in clean-tech at the time -and a landscape architect. Furthermore, various documents and analyses by others (Barba Lata & Duineveld, 2019; Donovan, 2017) were studied and complemented with observations.

Case 1: Werkspoorkwartier
The area Werkspoorkwartier (WSK) -approximately 60 ha in size -is located in the northwest of the city Utrecht as shown in Fig. 3, and originated in the settlement of the Werkspoor-factories, manufacturing e.g. freight wagons for the national railways. When these factories left in the 1970's, WSK transformed into a more fragmented, multifunctional and service-oriented area with smaller industrial companies, business offices, the creative industry, municipal city-care services and leisure facilities. During the 2008 financial crisis, the area fell into decay, suffering from vacancy, pollution and criminal activity. Meanwhile, WSK had become a relatively central part of the city, given the growth of Utrecht. Therefore, a distinct vision on the future development of the area was needed, which was provided in 2012 by the municipality of Utrecht; the policy document "Ontwikkelingsvisie Werkspoorkwartier" (Gemeente Utrecht, 2012) intended an organic redevelopment towards an urban working landscape combining the existing city-care enterprises with the creative making-industry. Keywords included flexibility and innovation; the potential of becoming a creative, industrial hotspot was emphasized by comparisons with well-known breeding places, such as the NDSM shipyard in Amsterdam (de Klerk et al., 2017). Housing was specifically excluded. Moreover, the municipality conferred on itself a limited, foremost facilitating role.
From roughly 2012 to 2019, both conventional and nonconventional actors were involved in the transformation of WSK. We will focus on developments of relevance to identifying social entrepreneurs, beginning with the immense Werkspoorkathedraal (Photo 1), located centrally in the area (see Fig. 3). Until 2015, this building had been largely unused for years, but it had been the focal point of meetings and place making activities by various, informal actors aiming to draw attention to the potential of the area, spurred by the municipal vision of 2012 and Utrecht running as candidate for the 2018 cultural capital of Europe. One such actor was a duo of female, freelance professionals and 'friends' ('vriendinnen' in Dutch), collaborating on a project basis using the name Vriendinnen van Cartesius. They remain active until present by facilitating the area-wide network and facilitating communication -thus spurring the overall development of the area -and established collaborations with the municipality and the joint association of businesses in the area over time. They currently act as an intermediate between various stakeholders and their interests, depending on their large network and strong reputation, contributing to the realization of the 2012 policy goals, without pursuing physical developments themselves. We consider them one of the social entrepreneurs in WSK in a primary role of facilitator. In 2015, the Werkspoorkathedraal was turned into a temporary urban campsite on occasion of the start of the Tour de France in Utrecht; afterwards it was transformed into an event location and offices for creative entrepreneurs by a well-respected, local real estate developer. One of the initiators of the temporary transformation however, was an individual, self-employed architect and urban designer who also -in collaboration -won the Call for Plans for a small strip of wasteland in WSK, issued by the municipality in 2014. The winning concept, Hof van Cartesius (HvC hereafter), entailed an experimental, flexible and green working environment. The pavilions for small, creative and sustainable entrepreneurs -clustered around a collective garden -were to be built following circular principles and partly by the end-users (Hof van Cartesius, s.d.). After winning the Call for Plans, the individual architect was joined by a representative of an intended, larger end-user (Uitvindersgilde), together pursuing realization. We consider this informally collaborating duo as another social entrepreneur at that time: the initiators of HvC. After a long and laborious trial-and-error process, and after the sister of the architect joined the team and contributed business knowledge, in 2016 the formal cooperation HvC was established. We consider the cooperation HvC another social entrepreneur that emerged from the efforts of the initiators. The mission of cooperation HvC is to achieve social impact by being an example in terms of organic area development and sustainable, circular entrepreneurship. The later cooperation comprises a large internal network of end-users and e.g. volunteers. Moreover, a large external network of actors supporting the venture in different roles was built, illustrated by the involvement of the real estate developer who permanently transformed the Werkspoorkathedraal; this actor obtained the land of HvC from the municipality and granted usage of it to HvC against favourable conditions, as such adopting the role of landowner.
The initiators of HvC were also actively involved in establishing the so-called EFRO-consortium for the project called 'Werkspoorkwartier: Creatief Circulair Maakgebied', enhancing employment opportunities and circular development of the area, financed by the European EFRO Initially, to create working-places for their own professional activities amongst others, later aiming to develop and exploit flexible, sustainable working-places for (future) members of HvC and to generate social impact by becoming an example for circular entrepreneurship and organic area development.

Primary:
Developer, end-user and partly builder.

Secondary:
Boundary spanner and niche entrepreneur, given the deployment of all actions and strategies of the HOW parameters (Fig. 3).
No formal organization, limited network and relationships, few resources -> little or no power to realize development goals. Initially, to create working-places for their own activities; later aiming to offer working-places and exhibition space to young, autonomous artists + to serve a public goal in terms of being a place where people can enjoy art and culture.

Primary:
Developer and end-user and partly builder (i.e. in restructuring e.g. the existing building).

Secondary:
Boundary spanner and niche entrepreneur, given the deployment of all actions and strategies of the HOW parameters (Fig. 3).
No formal organization, considerable network, few resources, no formal organization -> little power to realize the development goals. fund (see: https://efro-wsk.nl/en). Members of this consortium include various stakeholders, such as HvC and the local real estate developer owning the Werkspoorkathedraal as well as various local knowledge institutes amongst others. In 2017, the first phase of HvC was realized; the second development phase is currentlyin 2020 -in progress. Fig. 3 shows the location of phase 1 and 2 of HvC in WSK and the general lay-out of phase 1, which is further illustrated by Photos 2, 3 and 4. The initiators of HvC are currently still active at HvC, mostly working from the collective, main building (Photo 2). A more comprehensive insight in HvC, its initiators and community is provided by the short movie that was made for the EFRO-project (see: https://youtu.be/l5b7TSxNVBM; English subtitles available via settings).
Another initiative with a role of social entrepreneurs -at the other side of WSK -is called (Photo 5) 'De Nijverheid', which started in 2017 and offers working-spaces for artists, a café with a terrace and exhibition spaces in and around an already existing building. De Nijverheid started as an informal collaboration by two artists: the initiators, later being formalized as both a foundation and cooperation. The target group are young autonomous artists, normally not yet capable of affording such working-places or exhibition space. The further aim is to serve a public goal, by creating a place where people can enjoy art and culture. We identified both the social entrepreneurs of De Nijverheid and HvC deploying all four actions and strategies of the HOW variable to overcome e.g. barriers, with differences however, given e.g. the plans of De Nijverheid being less complicated and because one of the initiators of De Nijverheid already had professional experience in project management and a relevant network. Noteworthy with regard to both initiatives is furthermore, that initial motives were driven by the mere search for an own working space for the activities of the initiators, later evolving into the larger social aims.
In 2018, as a result of the efforts of one of the initiators of De Nijverheid, a local foundation realizing and exploiting work-spaces for artists -De Plaatsmakerstarted redeveloping the adjacent, vacant building called De Havenloods (see Fig. 3). De Nijverheid and De Plaatsmaker since then joined forces in the informal collaboration called 'De Vrijhaven' (Freehaven in English), together aiming to become a breeding place and haven for creative talent and its cultural audience in WSK. In 2019, they explored possibilities for expanding their plans to adjacent plots, also involving new actors. An interesting aspect of this development is that the initiators of HvC -having gained a considerable reputation and position in WSK after realization of HvC-phase 1 -were attracted to provide advice in developing De Vrijhaven, as such not only disseminating their knowledge, but also strengthening their position.
The recent acceleration in developments by various conventional and non-conventional actors resulted in a growing attention for the area WSK, exemplified by the 2019 ABN AMRO Circular Economy Award being granted to WSK. Moreover, the municipality started reassessing the policy-document of 2012 in 2019 (Photo 5). Table 1 provides a detailed, structured overview of the social entrepreneurs in WSK, related to the data of the parameters.

Case 2: De Ceuvel
De Ceuvel is a small area, part of the larger Buiksloterham (BSH) area on the north shore of the river IJ in Amsterdam, with a heavy industrial history of shipyards. Given its central geography (close to Amsterdam Central Station; see Fig. 4), BSH has a large development potential. Conventional municipal plans for the large-scale transformation of BSH into a mixed working and living area were hampered for various reasons, one of them being the 2008 financial crisis. Therefore -during this crisis -the municipality started actively promoting alternative, creative solutions for organic redevelopment, inspired by the nearby, wellknown bottom-up development of the NDSM shipyard (de Klerk et al., 2017;Savini & Dembski, 2016). One was a tender by the municipality in 2010, for the area of the shipyard Ceuvel Volharding, which had been closed in 2000 and was heavily polluted. The tender aimed to generate plans for a creative, innovative and temporary use for the duration of 10 years. In 2012, a group of mainly young, self-employed, local architects won the tender with their plan for De Ceuvel. Some of them were already well acquainted with one another, given their collaboration on the nearby project called Schoonschip: a small, sustainable, floating village, located at the same canal as De Ceuvel (i.e. the Johan van Hasseltkanaal; see Fig. 4).
The plan of De Ceuvel included the intervention of covering the land with phytoremediation vegetation, which slowly and naturally cleans the polluted soil; old discarded houseboats were to be placed on this soil, connected by an elevated, meandering boardwalk, allowing usage of the soil but preventing contact with it. The houseboats were to be refurbished into working-places for artists and small, creative or sustainable enterprises. Furthermore, a café and terrace were part of the plan.
We consider the group of informally collaborating professionals -the initiators of De Ceuvel -as a social entrepreneur given apparent social aims, although not all initial motives are clear and some individuals were also driven by creating a working place for their own professional activities. The process towards the actual realization of de Ceuvel involved attracting both human resources in terms of other end-users and a large group of volunteers and financial resources such as donations, loans, funds and subsidies. The involvement of new partners further shaped and enabled the realization of the core mission of the later, formalized organization (i.e. association) of De Ceuvel. This mission is to be an example for the societal transition to a contemporary, circular way of living, i.e. living with low environmental impact and reusing materials, products and land (De Ceuvel, s.d.;Donovan, 2017;Steen & van Bueren, 2017a). For example, sustainability consultation firm Metabolic joined the team and further shaped the ambitions of becoming a testing ground for new, sustainable technologies. Related to this ambition, KWR, a research institute of the drinking water sector initiated a project for which a subsidyfrom 2014 to 2016 -was granted by the Dutch water sector. This project involved developing a 'clean-tech playground', demonstrating the possibilities of closing biological cycles within an urban environment in both De Ceuvel and Schoonschip. The cultural programming of De Ceuvel (e.g. workshops, lectures and exhibitions) further contributed to the realization of the goals of the later association of De Ceuvel, which we identify as another social entrepreneur in this case. Barba Lata and Duineveld (2019) address two characteristics of the later, larger community of De Ceuvel. One is the fact that a number of members were well established within Amsterdam's broader professional networks and the other is that some of them had already been involved in other grassroots initiatives in Amsterdam, such as Hannekes Boom near Amsterdam Central Station (see Fig. 4).
The interviewees of De Ceuvel mention a variety of obstacles that they had to overcome towards realization. Collective learning processes played an important role therein, exemplified by e.g. the experiments with retrofitting the houseboats, related to the costs, building regulations, obtainment of building materials and effective use of voluntary labour forces. Two interviewees mentioned the relevance of a specific strategic relationship in overcoming financial barriers, being the Amsterdam municipal body currently called Bureau Broedplaatsen, roughly translated as Bureau for Breeding Places in English. The emergence of this Bureau, formerly a municipal project and debated by e.g. Pruijt (2004), is strongly related Amsterdam's squatting-history and to the transformation of the NDSM wharf into a breeding place.
In 2013, realization of De Ceuvel started, followed by its opening in 2014. De Ceuvel rapidly gained local, national and international fame, because of extensive media attention and various awarded prizes. Moreover, Barba Lata and Duineveld (2019) address De Ceuvel as a "flagship sustainability initiative". Although a number of the early initiators aimed to create their own working-space at De Ceuvel, at current only some still reside there. The most prominent remainder still visible as such is the 'Metabolic lab' with its elevated greenhouse as shown at the left of Photo 6. The reason that only few of the early initiators still reside at De Ceuvel is, that the ventures of some of them grew so rapidly after realization of De Ceuvel, that they no longer 'fitted' De Ceuvel. An example is the architecture firm Space and Matter that now resides at the quay of the Johan van Hasseltkanaal opposite to Schoonschip. As suchfor some -De Ceuvel can be considered a key project in building a reputation, career and 'maturing' their business.
De Ceuvel -together with other developments -instigated a movement in BSH, focusing on sustainable development and circularity. One such other development is New Energy Docks: a former factory that became the home of local companies, who formed an active 'community of practice' aiming to bring sustainable solutions to market and to actively support the sustainable development of the Amsterdam region. In 2015, the separate agendas of more than 20 stakeholders in the areaincluding the municipality -were integrated into a collective, circular vision on the area: the Manifesto Circular Buiksloterham (Steen & van Bueren, 2017a). We identified another social entrepreneur on the larger scale level of BSH as a whole, dedicated to facilitating the execution of these circular policy goals (i.e. the manifest) as an intermediate actor, being Stadslab BSH (in English: Citylab BSH). Stadslab BSH is a foundation that identifies, recognizes and connects ideas and best practices and facilitates e.g. stakeholders to meet each other. We consider the emergence of the Manifesto Circular Buiksloterham and Stadslab BSH as spin-offs of the earlier realization and impact of De Ceuvel amongst others. As such, Stadslab BSH is related to the case of De Ceuvel (Photos 7 and 8). Table 2 provides a detailed, structured overview of the social entrepreneurs identified in De Ceuvel and -to limited extent -BSH as described above, related to the data of the parameters.

Social entrepreneur type A: The earlier pioneers from the creative industry
Our data (i.e. cross-case analysis) shows an initial, strong role of informally collaborating individual professionals, mainly from the creative industry, represented by actors 1.1, 1.3 and 2.1 (Tables 1 and 2), whom we perceive as the first type (A) of social entrepreneurs: the pioneers as shown in Table 3. Their initial motives were driven by the plain desire for their own working-space, shortly followed and expanded by larger goals and social missions. As such, the SVP (Austin et al., 2012) is recognized, but was preceded by pragmatic, individual motivations. Similar to commercial entrepreneurs in urban development, the pioneers adopt an intended, primary role as developer (e.g. by transformation or construction of real estate). This role intertwines with that of an intended end-user. Since the pioneers have few resources, nor a large, relevant network, they are in the position of having little or no power. Moreover, they have not yet formally organized themselves, i.e. have not established a legal entity for their venture. In order to change this position, the pioneers deploy all four activities of the HOW variable. They actively build social networks and mobilize resources by doing so, strongly appealing to their competences of bridging differences between, or connecting goals and interests of actors across sectors and building trust. Therefore, a secondary role of the pioneers is that of a boundary spanner (Williams, 2002). Furthermore, we perceive them as niche entrepreneurs (Pesch, Vernay, van Bueren, & Pandis Iverot, 2017).

Social entrepreneur type B: The consolidated organization
As a result of the efforts of the pioneers, larger (i.e. including more people), formalized, third sector organizations -represented by actors 1.2, 1.4 and 2.2 (Tables 1 and 2) -emerge over time, whom we perceive as social entrepreneurs type B: the consolidated organization(s) as shown in Table 3. They gained access over the necessary resources and have grown into the position of having realizing power. By differentiating between social entrepreneurs type A and B, we introduce a time element, representing both a shift in position and power, but also in the level of aggregation from informally collaborating individual actors to formal organizations (Avelino & Wittmayer, 2016) by means of associated bottom-up processes of self-organization (Moroni, 2015;Portugali, 2000). These shifts showcase one of the differences with commercial entrepreneurs. Contrary to our social entrepreneurs, commercial entrepreneurs generally enter processes from an already existing professional organization and a position in which paid human resources are available and other resources (i.e. finances and land) are or can be made available by means of institutionalized instruments (e.g. a PPP) or via an already established network (Austin et al., 2012). Initial motives are diffuse and partly unknown, but some were motivated by creating working-places for their own activities. This evolved into aiming to create a sustainable, innovative breeding-ground or 'clean-tech playground' and offering self-built working places for creative and social entrepreneurs + to be an example for the societal transition to a contemporary, circular way of living.

Primary:
Developer, end-user and partly builder.

Secondary:
Boundary spanner and niche entrepreneur, given the deployment of all actions and strategies as indicated by the HOW parameters (  Fig. 3).  The combined, primary roles of developer and end-user -which are conventionally mostly separated -continue in social entrepreneur type B. Furthermore, we see the later organizations adopting an additional role of the builder of the developments to a certain extent, for example by self-finishing façades of pavilions (HvC) or by retrofitting existing structures (De Ceuvel and De Nijverheid). In all cases, the consolidated organizations largely exist of end-users, being the members of the cooperation (actor 1.2), foundation (actor 1.4) or association (actor 2.2). These end-users -amongst others -provide the human resources needed to fulfil the role of the builder apart from them being mere end-users. One can assume that the reason for adopting the partial role of the builder is financial, since it is less expensive to build yourself, than to attract a separate builder. However, it is also a way to enlarge the commitment of those involved to the initiative. We perceive the combination of roles of social entrepreneurs types A and B -and its consequences -as another, important difference with more conventional, commercial entrepreneurs. Contrary to our social entrepreneurs, conventional developers mostly -after completion -transfer the product to an owner or end-user and move on to another project, with the possible consequence of a limited bonding with a specific place and its surroundings. This is in contrast to our social entrepreneurs who have a strong connection to the localities they operate in, which is physically expressed by the integration of cultural-historical references in their plans. For example, the concept of De Ceuvel revolves around the re-use of discarded boats, referring to the former shipyards in BSH and Amsterdam's harbour and many waterways, to be recognized in the layout of Amsterdam (Fig. 4). Another example is the usage of old, discarded railway tracks as columns in the pavilions of HvC (see Photo 4). This is not only an example of circularity, but also a symbolic reference to the historic relationship of Utrecht with the national railwaysrecognizable in Fig. 3 -and of WSK in particular. We perceive these references as merely the tangible, visible representations of the deeper mental connections the social entrepreneurs have or create with the place.
The later, consolidated organizations continue deploying similar activities as the pioneers. However certain activities will require less or different efforts over time, given a certain established position or realization of goals. Part of the activities of building social networks is creating the internal network of the organization, attributing human resources (i.e. labour force and competences) to the venture. The interviewees of HvC refer to this group as the community and the activities to create it as community building, stressing the importance of this activity. The notion of community in this context should not be mistaken with the community in Fig. 1 (i.e. sector IV) however, since the community in our cases is much more diverse than mere citizens, as stated. The mobilization of finances and land is the result of building an external social network, contributing these necessities. The consolidated organizations maintain strategic relationships (i.e. interdependencies) with actors from either sector I, II or III fulfilling roles of e.g. the financier, landowner or regulator. Similar to the pioneers, within the consolidated organizations we recognize roles of individual boundary spanners and niche entrepreneurs, oftentimes represented by the same individuals as the pioneers.
The abovementioned findings concerning social entrepreneurs type A and B are the result of our detailed analyses of the two Dutch cases. It should be noted, however, that we recognized similar patterns of actorswith corresponding characteristics -evolving over time in general explorations of comparable Dutch and Western European cases. Such cases include for instance Open Lab Ebbinge in Groningen (Bekkema et al., 2016), GOUDasfalt in Gouda (Bisschops & Beunen, 2018) and Holzmarkt in Berlin (Holzmarkt Co-operative Association, 2013).

Social entrepreneur type C: The intermediate agent
When we oversee WSK and the larger area BSH, we can identify another type of social entrepreneur -represented by actors 1.5 and 2.3 (Tables 1 and 2) -whom we perceive as social entrepreneurs type C: intermediate agents, as shown in Table 3. These actors -also pursuing social values -function as intermediates between various stakeholders by communicating, facilitating network meetings, interpreting and connecting goals and interests, launching interactive platforms, etcetera. They do not pursue the role of developer; they adopt a primary role as facilitator of urban developments, aiming to realize and reach specific policy goals. It can be argued, that the apparent need for, and existence of this facilitative role is inherent to organic urban development. Buitelaar et al. (2012) substantiate this finding, given their identification of similar actors (i.e. intermediary parties) in their analyses of Dutch organic urban development practices. We found that e.g. the establishment of Stadslab BSH (actor 2.3) was the result of the recognition of various committed individuals, that such a role was urgently needed in the area. The intermediate agents we identified, specifically act as boundary spanners (Williams, 2002) and since they deploy activities motivated by the promotion, articulation and execution of certain governmental policies, we also regard them as policy entrepreneurs (Kingdon, 2011).
The professional background of the individuals collaborating as intermediate agents varies, but they are generally higher educated. Some position themselves using the Dutch term 'kwartiermaker', which best translates as 'quartermaster', to be understood figuratively and referring to a person paving the way for certain developments. The specific sector ( Fig. 1) in which these intermediate agents can be positioned is diffuse. The intermediate agents focus on limited activities of the HOW parameters and their position depends on the social network they succeed to establish and maintain, as well as on their reputation within this network.

Conclusions and discussion
This article aimed at analysing and categorizing the new, nonconventional actors involved in bottom-up urban development, in order to start filling the gap in knowledge on bottom-up initiatives. We think that a better understanding of these newcomers can contribute to effective strategies -for various actors involved -towards realization of such initiatives, thus spurring new ways of governing the development of urban areas. We provided a general typology, in which three types of social entrepreneurs are described, who have a similar aim of pursuing social values. The first and second types are the early pioneers and later consolidated organizations respectively. They combine roles of a developer and end-user amongst others, whereas the third type we identified -the intermediate agentdistinguishes itself by a facilitating role. The social entrepreneurs we studied played a pivotal role in the initial phases of organic urban redevelopments of former industrial areas, as such instigating wider developments. Contrary to earlier, more activist manifestations of bottom-up initiatives, they do not oppose the establishment, but actively seek cooperation with various actors in order to reach goals, aiming at socio-technical innovation and sustainability. Moreover, we see governmental bodies increasingly acknowledging the efforts and impacts of these social entrepreneurs and even actively spurring such action. Therefore, we consider these emergent practices as a next step or new stage; instead of resistance and activism, actors actively work together with the broader, more visionary aim of shaping alternatives for sustainable future cities. In that sense, these entrepreneurs can be considered the embodiment of the network society, in which governance is no longer the prerequisite of government, but the result of the interplay of governing actions by multiple stakeholders.
Moreover, the analyses confirm that the actors involved in bottomup urban developments have a hybrid origin, as they can be positioned in different sectors and should not be considered mere citizens. These new insights can help understand the position of the initiators of bottom-up developments as well as their differences with other (i.e. conventional) actors; it can reveal possible causes of friction and thus prevent barriers to emerge.
We have shown that perceiving the actors and their activities from a social entrepreneurial angle and strategies of niche formation theories offers a new way of understanding and positioning them. Introducing such business, network and transition management concepts within the domain of urban planning and development, enriches our understanding of and perspectives on ongoing socio-spatial transitions. It offers a lens of diversification and recognizes the variety of intentions, roles, and powers that shape our cities from the bottom-up. In addition, by developing a typology of social entrepreneurs we contributed to academic debates in planning literature on the perceived divide between rational comprehensive planning and incremental planning. The typology illustrates that bottom-up initiatives in essence are or have become embedded within existing institutional settings and established practices, with social entrepreneurs being manifestations of actors acting at the hybrid interplay between both planning approaches. Therefore, both the used managerial concepts and developed social entrepreneurial typologies offer opportunities for planning scholars to view and study contemporary planning practices from a different less dichotomous angle. Reflecting upon these typologies of social entrepreneurship from the dichotomy of neoliberal vs. social innovative discourse, we see that the social entrepreneurship displayed by these actors is fully in sync with the wider neoliberal institutional setting, with social entrepreneurs filling in the space provided by state and market for 'bottom-up' action.
This paper constitutes two limitations. Firstly, our empirical study is limited to two Dutch cases. It remains to be seen whether the developed typology applies to a larger population of cases. Therefore the generalizability of the findings can be questioned. Nonetheless, as mentioned in the previous section, we perceived analogies with other Dutch and Western European cases; we therefore expect affirmation of our findings, but strongly recommend testing and enriching the social entrepreneur typology by conducting empirical work in other development and planning contexts. A second limitation, relating to the application of the theory of social entrepreneurship, is that it can be questioned whether the actors involved acknowledge themselves as social entrepreneurs. The mere social value motivation of the pioneers can be disputed, given the fact that during the financial crisis for instance many architects and urbanists were short on assignments, therefore deploying creative ways to generate work. One can assume this need for work to have been part of the motives of a number of pioneers and intermediate agents. Further elaborating on the distinction between commercial and social entrepreneurship, we remark that our cases revealed many hybrid actors, showcasing a certain balance in pursuing both commercial and social values, thus illustrating our point: social and economic values can be pursued simultaneously by social entrepreneurs.
Future research by the authors will therefore address the other variables of the analytical framework (Fig. 2) in terms of the pathways of the social entrepreneurs (i.e. their strategies) and the social impact (i.e. relevance) of their ventures. In addition, we strive to deepen insights in the complex, layered roles of local government as a regulator, facilitator and e.g. landowner. A salient given in this respect is that a number of the initiatives we studied are the result of a 'Call for Plans' or tender issued by a municipal body. One can question the 'bottom-up' character of these initiatives as such, since the 'recognition of an opportunity' by the initiators was a direct result of a government intervention.
A recommendation for future research in the field of social urban entrepreneurship is to analyse the career paths of the pioneers and the roles of their successors in the consolidated organizations. We found that in some cases, the pioneers left the organization and in others, pioneers are looking for ways to perpetuate the organization by making it less dependent on themselves as individuals. Further elaborating on this, we observe social entrepreneurs in bottom-up urban development creating a certain ecosystem, from which other projects and new initiatives emerge. These 'ecosystems' -with similarities to business ecosystems (Moore, 1993;Moore, 2006) -safeguard the social values that have been created, perpetuate the position of the pioneers and offer new business and career opportunities. This observationand the proposed theoretical lens of business ecosystemscould be an interesting starting point for future analysis.
Finally, based on the findings, we formulate some recommendations for practice and planning policy. First, this paper indicates that social entrepreneurs are actors that strive for both social and economic impact within cities focusing mainly on revitalizing urban areas. Planning and development agencies could look for opportunities to stimulate and support the realization of such entrepreneurial initiatives, especially if they contribute to achieving planning and development policy ambitions. Second, that said, local planning agencies responsible for planning policy formation should find ways to include and translate societal needs and ideas advocated for by the many social entrepreneurs in cities within urban policies. This would not only increase societal support for policies themselves, but would also potentially strengthen the implementation of such policies. Third, it is important to emphasize that social entrepreneurs and their activities could potentially contribute to effectively dealing with the context-specific challenges cities face, as social entrepreneurs are intrinsically motivated by positively impacting the built environment with innovative ideas and practices. Therefore, we advocate for developing and executing collaborative strategies of third ways of planning allowing bottom-up initiative to become a more significant factor in contributing to the many sustainable transitions cities are facing worldwide.