1. Introduction

1Waiting spaces are built or unbuilt public or private sites that have been abandoned by the previous use(r) and are awaiting reallocation for a new use. [Faraone and Sarti, 2008; Studio Urban Catalyst, 2012; De Smet, 2013]. Either a new function has yet to be determined for these sites, or the realisation of an already defined future function has been delayed. The reasons behind the existence of waiting spaces can vary. They can be the result of fallout from lengthy planning processes, financial complications, or unexpected technical issues. However, these spaces always seem temporarily “out of use”. During this idle time, these areas seem available and suitable for answering citizens’ urgent unmet needs.

2In this paper, we recount our experiences of finding a suitable location for the Solidary Mobile Housing Pilot Project. This venture was part of the Solidary Mobile Housing (SMH) project, an ongoing living lab project aimed at developing and testing a model for the co-creation of solidary living in mobile houses for homeless people on un(der)used urban spaces in the Brussels-Capital Region (BCR). Based on this experience and knowledge exchanges with key experts and field actors, we assess the possibilities and limitations of using un(der)used spaces to provide an immediate (although partial and short-term) answer to the current affordable housing crisis through the provision of temporary housing.

1.1. Temporary use of waiting spaces

3In the first half of the 20^th century, following the transformation from the industrial to the post-industrial era, cities in developed countries were confronted by leftover production spaces. The focus was initially on reintegrating these sites as quickly as possible in a planned and end-result oriented way. However, in the context of the economic recessions of the 1970s and early 2000s, researchers and practitioners became intrigued by the exciting activities and everyday practices taking place in urban waiting spaces, despite failing or stalling official redevelopment processes [Miessen and Cupers, 2002; Urban Unlimited et al., 2004]. In search of cheaper or easier-to-realise solutions, the temporary use of un(der)used urban spaces became the subject of several publications in the fields of urbanism, urban planning, and urban management [Haydn and Temel, 2006; BBR, 2004, 2008 and 2012; Senatsverwaltung für Stadtentwicklung, 2007]. Several authors studied and reported on how practices of temporary use can offer room for “informal” actors [Groth and Corijn, 2005] to experiment with alternative realities [aaa-PREPAV, 2007]. Interest too grew in how they could play a role in defining a more open, collaborative, responsive, and transversal approach to urban (re)development [Nicolas-Le Strat, 2007; Bishop and Williams, 2012; De Smet, 2013; De Smet and Van Reusel, 2017; Oswalt et al., 2013]. It was also recognised that these un(der)used spaces could offer interesting opportunities for the bottom-up creation of collective spaces [Ferguson, 2014]. For this reason, in recent years, many cities began experimenting with the temporary use of waiting spaces as a tool for upgrading the city [Refill, 2018]. A great number of projects have emerged, with some actors seeing the use of waiting spaces as an eminent opportunity to address unmet needs, such as the pressing demand for more and higher quality affordable housing.

1.2. The affordable housing crisis in the Brussels-Capital Region

4The BCR faces severe social and economic challenges related to poverty and housing. The increasing number of households on the waiting list for social housing (48 804 in 2018) alone illustrates a lack of social housing where less than half (44,9 %) of the demand is currently met [Observatorium voor Gezondheid en Welzijn van Brussel-Hoofdstad, 2018]. Many BCR inhabitants are thus forced to turn to the private market, where rents are not adapted to their financial means [fonds.brussels, 2015]. Moreover, the overall number of homeless people has more than doubled (+ 142,2 %) between 2008 and 2018 [Quittelier and Bertrand, 2018: 23]. As a result, many citizens are living in unhealthy, overcrowded, and/or overly expensive housing, in homeless reception centres or on the streets. Due to a lack of alternatives, these people often feel they have little or no influence on their housing possibilities. As the housing market does not answer the needs of many inhabitants, the right to housing is currently not guaranteed within the BCR. In the context of the affordable housing crisis [Romainville, 2015], there is a clear need to develop alternative forms of housing that are better oriented to vulnerable people, especially those facing homelessness and housing insecurity.

5In contrast with this qualitative and quantitative housing shortage, the BCR is simultaneously confronted by a considerable number of spaces waiting for redevelopment [GSSO, 2006; ADT/ATO, 2016]. These include large-scale sites – such as Weststation, Tour & Taxis and the canal zone – as well as many smaller areas dispersed across the Region. In a 2016 study, the BCR Territorial Development Agency identified several of these areas as suitable for temporary use until future projects are realised [ADT/ATO, 2016].

6In this context, a variety of experimental initiatives have recently emerged that focus on temporary mobile/modular housing for vulnerable target groups [De Smet et al., 2018a]. These fit within a tradition of temporary use projects in Brussels, and are taking place alongside existing or new temporary use initiatives centred on gardening (e.g. by Le début des haricots), culture and youth (e.g. by CityMine(d) and Toestand), collective living (e.g. by 123 Logements and FéBUL) or a mix of functions (e.g. by Communa), and more commercial initiatives such as vacancy management and pop-up businesses (e.g. by Lancelot or Entrakt) [De Smet, 2013].

1.3. Aims, methods, and research questions

7This paper opens with a description of our experience in the context of finding a suitable temporary use location for the SMH Pilot Project. We then evaluate the methods and tools used, and the outcomes and challenges encountered over the course of this venture.

2. The Solidary Mobile Housing (SMH) case

9The SMH Pilot Project was initiated by SAAMO Brussel, a non-profit organisation focusing on community building; the KU Leuven Faculty of Architecture; and Centrum Algemeen Welzijnswerk (CAW), a non-profit organisation providing individual support on general wellbeing. The initial assumptions behind SMH were drawn from SAAMO’s previous experience with providing temporary housing for people in precarious situations; KU Leuven’s ongoing research on participatory and inclusive design, temporary use of waiting spaces and alternative urban projects; and CAW’s know-how on the guidance of homeless citizens.

10The four main goals of the SMH project are to (1) develop a housing co-creation process focused on empowering the various stakeholders; (2) design a qualitative and affordable mobile and adaptable housing typology that can accommodate individual housing preferences as well as provide collective spaces; (3) elaborate methods and tools for strengthening small-scale solidarity networks, both between the participants and with the surrounding neighbourhood and (4) involve vulnerable citizens in discussions about the temporary use of urban waiting spaces.

11To realise these aims, from 2017 until today, several partners have been working closely together in the SMH Living Lab.

2.1. Presentation of the SMH Living Lab

12The stakeholders included in the SMH Living Lab are:

• eight future inhabitants: homeless people from the BCR who lost control over their housing situation;

• community workers from SAAMO Brussel;

• social workers from CAW Brussel;

• architect-researchers, lecturers, and students from the Faculty of Architecture of KU Leuven

• local and sub-local authorities (municipal administrations, social welfare services, the BCR’s Housing and Urban Planning departments, and Service for Environment and Energy);

• several professionals within the BCR from offices and organisations including w-o-l-k-e, BC architects, Casablanco, Atelier Groot Eiland, and Sociale Innovatie;

• surrounding inhabitants and neighbourhood organisations.

13From the outset of the project, these partners have been working together to co-create the SMH Model (as a housing co-creation method incorporating social guidance and skill-building methods and tools, a service-learning methodology, and preliminary financial and legal strategies as well as a modular and circular construction system) and, in parallel, co-realise the SMH Pilot Project. (Figures 1a and 1b).

14Since the future inhabitants are homeless citizens, the notion of solidarity is central to the project. To promote social interaction and mutual help and support at different spatial scales and social strata, the SMH Pilot Project includes indoor and outdoor collective spaces to enable meaningful encounters between inhabitants, other project partners, and the neighbourhood.

15The methodology employed in the SMH Living Lab consists of participatory action research [Kemmis and McTaggart, 2005]. Between 2017 and 2021, four main action research cycles took place, each with specific goals to be realised through smaller steps (Figure 2). The focus of this paper is on the location-finding process, which mainly took place in the first cycle: the co-planning phase.

16To actively involve homeless end users in the SMH Living Lab, a future inhabitant engagement process was initiated at the start of the project (see Appendix 1 for a more detailed explanation). As a result, after a few months, a group of eight future inhabitants joined the project as full-fledged collaborators. Several participatory activities were organised during each cycle to facilitate their involvement in each step of the co-creation of their own houses. The openness of the action research approach enabled us to use different methods and tools adapted to the specific needs and wishes of the participants, and the particular goals of each of the research and development process stages, including semi-structured interviews, online surveys, photo-elicitation, timelining, collective site visits and study trips, co-design and construction workshops, participatory mapping, focus groups, co-design and co-construction workshops, and inclusive brainstorming and evaluation sessions. Throughout the project, the SMH Living Lab took different forms toward the goal of co-creating a learning environment with all the partners, including the homeless future inhabitants, a stakeholder group that is usually not consulted and generally has little to say about their own housing situation.

17The hypothesis behind the SMH Model is that, by taking part in every step of the housing co-creation process, homeless people not only regain control of their housing track but also on their whole life. To support this, the SMH Model includes intensive individual and group guidance, which, among other goals, aims to help participants transition to a more permanent housing solution while also allowing for the possibility of moving with the project from one site to another, if desired.

2.2. Description of the SMH approach to the discovery, selection, and negotiation of a temporary use site

18The ambition was to locate SMH on sites that would fit the collectively determined criteria. Therefore, we needed to develop a co-creative method for: (1) identifying potential locations (site discovery); (2) selecting a suitable location (site selection); and (3) negotiating a temporary use agreement with the site owner.

19These three aspects had to be developed simultaneously and in interaction (Figure 3). In what follows, we discuss each of these steps in more detail.

2.2.1. The site discovery process and the definition of site selection criteria

20To discover potential locations for the Solidary Mobile Housing and collective space(s), we combined three methods. As one of the project’s goals was to align with the BCR’s current urban planning aims and strategies, we started with a “top down” approach, in which we obtained a list of potential sites from the Regional Planning Agency, perspective.brussels. This approach was combined with a “targeted enquiry”, in which we invited institutional landowners like social housing companies, the Regional Development Agency, and the 19 municipalities to participate in our project by making un(der)used sites owned by them available to us. We contacted them through phone calls, face-to-face meetings, and/or written requests (letters). Finally, we complemented this with a “bottom-up” approach executed by the project partners. This involved roaming the city to identify un(der)used sites, contacting field actors within our own networks, and scanning (social) media reports for location opportunities. Combining these three approaches yielded a longlist of approximately 200 “possible” sites.

21To select one or more suitable locations from this longlist, we then needed to define a set of socio-spatial suitability criteria. To determine these, we studied criteria in the literature on affordable housing location methods [Ackerson, 2013; Aldrich and Crook, 2013; Jennings, 2012; Shimberg Center for Housing Studies, 2017]. This review revealed a significant number of – sometimes contradictory – approaches for determining the suitability of sites. For example, in their analysis of siting explanations, Aldrich and Crook [2013] note that besides technocratic reasons and political choices, social vulnerability and social capital also played an important role in Federal Emergency Management Agency (FEMA) trailer siting after Hurricane Katrina. Another case study, that of the Affordable Housing Location Model developed by the Iowa City Planning and Community Development Department, the city attorney's office, and the Metropolitan Planning Organization of Johnson County puts a lot of stress on gauging elementary school diversity, as living conditions associated with poverty are seen as a barrier to student learning [Ackerson, 2013]. Another tool for place-based urban revitalisation strategies, the neighbourhood distress score, includes public safety variables in addition to housing, education, employment, poverty, and income levels [Jennings, 2012]. Finally, the Housing Suitability Model (HSM), developed by the Shimberg Center for Housing Studies, the Department of Urban and Regional Planning, and the GeoPlan Center, recognises that objectives can conflict with each other. As a result, the Shimberg Center points out that thoughtful siting of affordable housing requires more than just a consideration of land costs, and advocates that a multiplicity of criteria should be considered to find locations where affordable housing objectives would reinforce each other [2017]. This literature review made it clear to us that it would be impossible to develop an optimal (general and prescriptive) set of location selection criteria. Instead, a case-based, satisficing³ solution was to be determined, one in which the search for alternatives was carried out until particular suitability and acceptability thresholds, determined in consultation with the future users, were met. Our next step was to organise a series of collaborative reflection sessions with all the project partners. In this way, we co-defined three types of location criteria for SMH: exclusion, ranking, and soft criteria (Table 1).

Table 1. Overview of collectively defined socio-spatial site selection criteria for SMH

22Because the project had just started, future user engagement was still in progress at that point. Therefore, the CAW and SAAMO social and community workers involved in the project were asked to bring in the end-user perspective based on their extensive experience working on housing issues with this target group.

2.2.2. The site selection process

24The first step involved applying the exclusion criteria to discard unsuitable sites. Sites that were polluted, at risk for flooding or characterised by a land use category for which a housing project could not be approved were thus eliminated, resulting in a list of approximately 60 “potentially suitable” locations. As this number was still too extensive, we needed to find a way to further filter and prioritise the sites using the ranking criteria.

25As our literature review had taught us that we needed to use a case-based rather than a general and prescriptive method for site selection, we decided to adopt a scenario-based approach as the second step of the “broad-to-narrow” method. Working with KU Leuven architecture students, we first organised a partner workshop to develop a range of possible site selection scenarios drawn from our literature study of affordable housing location methods (Figure 5).

27We then organised another partner workshop to collectively discuss the survey results. After this meeting, the students created a specific weighted site selection criterium scoring system for each scenario. This allowed us to further filter the remaining sites in a qualitative and systematic way. Using these scores, the top three sites for each scenario were selected. Additionally, by offsetting areas of pedestrian accessibility (5 minutes on foot) to supporting facilities such as shops, healthcare and social services, public green spaces, and public transport hubs, we created a “favourable areas” map. Based on this analysis, poorly served areas were re-evaluated. This process resulted in a shortlist of 16 “priority” sites. However, to increase our chances of identifying the best possible location, we also continued the “targeted enquiry” and/or “bottom-up” site discovery, repeating the filtering process described above for each newly discovered place. As a result, four more potentially suitable locations were added to the students’ shortlist of priority sites.

29As the final site selection would depend on the outcome of negotiations with the site owners, launching these discussions was the next step in the process.

2.2.3. Negotiation of a temporary use agreement

30The goal of the negotiations with the owners was to obtain an agreement for the temporary use of one of the desirable sites. In this context, a site ID card was drawn up for each of the six sites that were still “in the running”. These cards included all the relevant information gathered about the sites to that point, including the address, an aerial view and site photos, data on the available surface and eventual amenities, ownership information, data on the history and future plans, some neighbourhood information, and a site evaluation from the perspective of our project (Figure 8). These cards were regularly updated.

31Since the negotiations did not immediately provide an opportunity in the short term, the “targeted enquiry” and “bottom-up” site discovery were continued with all the project partners, including the future inhabitants. The filtering described above was repeated for any newly discovered sites. If a site turned out to be both suitable and desirable, it was added to the shortlist, and negotiations were started with the owner. Informal time limits were placed on negotiations for a specific site; if they did not yield results in a reasonable amount of time, the site was removed from the list.

2.2.4. Result: the SMH site in Jette

32After several months of temporary use negotiations, we finally reached an agreement with the Jette municipality for the use of a site within the newly started urban redevelopment project, the “Magritte Neighbourhood Contract”, which would be freely available to us for three years. This also led to our project's inclusion in this urban redevelopment scheme. The one constraint was that the municipal site would only become available the following year. However, we were able to close an agreement for the use of an adjacent plot owned by a cultural organisation for the interim period.

3. Conclusions

33Based on the experiences described above and knowledge exchanges with key experts and field actors, we can now draw some conclusions about the methods and tools used, and the outcomes and challenges encountered in the context of the SMH Pilot Project. Moreover, we can also make some more general observations about the possibilities and limitations of using Brussels’ un(der)used spaces to provide an immediate (although partial and short-term) answer to the current affordable housing crisis through the provision of temporary housing on urban waiting spaces with and for vulnerable people.

3.1. Findings from the SMH location process

34With respect to the overall site discovery and selection process, we are convinced that a mixed method approach, co-defining the selection criteria, scenario development, along with surveys and workshops, were satisficing, inclusive, and effective methods for meeting the needs and demands of the different project partners. For example, we noticed how future inhabitants started to develop place attachment even before the pilot project construction began. Although the SMH Model involves providing temporary housing on urban waiting spaces, this model by no means aims to hide away homeless people in a forgotten corner of the city. On the contrary, during the site discovery and selection process, we noticed how, in the context of SMH, waiting spaces are transformed into spaces of negotiation where people can claim their right to the city and move toward reaching their potential and achieving their aspirations. This became obvious during collective site visits, which allowed all the involved actors, including the future inhabitants, to engage in discussions on socio-spatial inclusion and the right to housing. Furthermore, the inclusion of the SMH Pilot Project in the Magritte Neighbourhood Contract later provided an interesting entry point for involvement in local networks.

35Concerning the different site discovery methods, our experience with each of the three methods revealed constraints as well as benefits. The “top-down” approach, although rigorous and verifiable, has the downside of bringing no contact with the site owners until after the selection process. It was unclear from the start whether the owners would indeed be open to temporary use. Moreover, the efficiency of this approach depended on the quality and reliability of the available information (especially whether it was up to date). In contrast, the “targeted enquiry” allowed us to contact many people and present the project to them. A major drawback of this method was that it took a lot of time. The success of this approach ultimately depended on whether the “right” person could be identified within the institution or company, which was not always evident. Finally, the “bottom-up” approach, while offering the possibility of yielding very “hot off the press” information, required substantial time and effort, as we had to figure out everything ourselves, including finding answers to such questions as who is the owner? What is the term of vacancy? Are there any other projects already planned for the site? Furthermore, regarding the final site selection process, we clearly noticed the importance of physically visiting a site as opposed to exploring it virtually via digital maps or Google Street View.

3.2. General conclusion

37We can conclude that one of the first conditions for using Brussels’ waiting spaces for temporary housing for vulnerable groups would be facilitating site discovery and selection. Although each of the 19 municipalities of the BCR is supposed to have an up-to-date list of vacant properties on their territory, most of them lack this information. No actual database of un(der)used urban spaces, not even of public terrains, is available. This makes finding suitable sites for temporary housing a very time- and energy-consuming activity.

38Furthermore, as mentioned above, getting access to temporary use locations for housing was another critical threshold we encountered. Other actors share this experience. Although the BCR seems to support temporary use, including for housing – as the “Modular Housing Call” launched by the BCR State Secretary for Housing in 2018 infers – a clear operational framework is currently lacking. As a result, project organisers are, for the most part, operating in a legal grey zone. This seriously complicates the negotiation of agreements with site owners. Furthermore, it also inevitably has repercussions on the end users, as there is much confusion, for example, about the types of contracts to be made, the legal responsibilities of the involved parties, and the possibility for the inhabitants to officially register their residence on the sites.

39During the SMH location-finding process, we also learned that our assumption that public owners would be more willing than private owners to open their sites for temporary use was incorrect. In our experience, public owners seemed to favour more “easygoing” (trendy, low risk, and even monetisable) types of use rather than socially oriented temporary housing projects. This might be a consequence of the delicate nature of this specific type of temporary use. In general, all site owners seemed wary that temporary housing residents might be hard to remove when they want to reclaim their terrain for other uses or development.

40In conclusion, our research shows how temporary housing projects on urban waiting spaces can indeed offer room for “informal” actors to experiment with alternative solutions to current socio-spatial challenges. For however long the affordable housing crisis continues, it definitely seems worthwhile to further explore how temporary housing for vulnerable target groups could be structurally embedded in urban redevelopment schemes and how site owners could be motivated and better supported to make their un(der)used properties available for such projects.