Urban Agriculture as a Catalyst for Revitalization Processes in Residential Districts of European Cities. The Case of Anderlecht, Roeselare and Romainville

The need to implement urban agriculture as a tool for transforming existing cities, rather than just designing the cities of the future, is emphatically written about by Vikram Bhatt, Leila Farah, Nik Luka and Jeanne M. Wolfe in the earliest of the publications analyzed [20], discussing that the revitalization of the urban fabric through introducing urban agriculture is not about ploughing up everything that is not buildings and introducing waving patches of grain. It is about finding under-invested sites that do not fully exploit the potential of existing structures and enriching them through the implementation of a policy of greater social and spatial coherence [20]. Although this example concerns the area of Montreal and McGill University’s downtown campus, it nevertheless demonstrates the potential of experimental actions for the revitalization process of an area of education, research and housing through incorporating participatory processes, the simplicity, replicability and reproducibility of the proposed solutions, while at the same time their variability (modularity and seasonality) [20].

European research in the past few years has focused on revitalizing transitional areas, particularly periurban agriculture [21]. Studies have looked at traditional agriculture in areas affected by urban sprawl from 1970 to 2015 [22]. Similar studies in Portugal examined conditions for local food production systems. There is a link between urban agriculture in Europe and urban regeneration efforts to combat social issues like depopulation and integrating historical agricultural landscapes into urban structures [23, 24]. The studies focus not on modern urban agriculture but on traditional forms found in urbanized areas or transition zones. The main factor examined has been the landscape and its changes due to urban agriculture development, emphasizing the need to protect rural landscapes in transition zones [25, 26].

The use of the food-water-energy nexus in the process of revitalization of cities is described as a great potential and a useful tool in most of the proposed strategies for Europe [27] by maintaining local character and a unique sense of place, creating inclusive mixed-used urban living and high-quality architectural design and public space as a catalyst for a better city. Thus, the combination of sustainable development strategies and urban residential regeneration in Europe has already been recognized and linked to elements of fresh food production. It has already been described that urban farming can provide an element of the metropolitan revitalization program and a component of integrating greenery and buildings into the urban landscape [28].

The analyzed facilities adopt a business model referred to in the literature as low-cost specialization, characteristic of crops with high added value due to transport and storage costs, freshness and perishability, all of which make them still profitable despite the increased costs of cultivation [29]. This type of cultivation – performed on a relatively small area of expensive land and thus requiring greater efficiency, such as greenhouse cultivation, to increase profitability – has been diagnosed as profitable for many European agglomerations, including Paris [30], Copenhagen [31] and The Hague [32]. Using the flowchart of the low-cost specialized urban farms analysis, the study was repeated for the reviewed examples to confirm which of the detailed models urban farms gravitate to [29] (Table 3).

In 2015, research summarising future directions and global trends in urban agriculture development suggested that vertical indoor agriculture designed for this purpose or re-purposed will mainly serve intensive horticultural production or only the building envelope will be used as a form of bioreactor for algae production [33].

The value of proposed technical solutions was questioned, but now the focus is on adjusting urban-fringe relationships, using wasteland, peri-urban agriculture, and planning strategies [33]. Nigel Curry identified multifunctional agriculture and sustainable land use as key criteria [33]. Housing’s role in sustainable urban development was recognized even earlier, but its connection to urban agriculture as a policy element in settlement revitalization is more recent [34]. Siv Skar and her team noted the importance of urban agriculture in mitigating the effects of climate change in cities [35], thus reinforcing the effect of people’s shift back towards living in green city centres also through the potential to increase the availability of fresh, unprocessed food in central areas. At the same time, despite the recognition of the urban agriculture element in Europe as part of a sustainability policy, unlike other elements of urban infrastructure, agriculture remains an undervalued, underestimated, and under-invested element [35]. Besides, in the typology of urban agriculture presented in the same study, primary attention was paid to the elements ofagriculture considered typically found in cities [35]. The glasshouse element has emerged here potentially as one for use on façades or roofs. Despite this potential, sustainable food systems are still overlooked in European policy [36], and their potential to initiate the process of urban renewal is also lacking. An example of this can be found in the new European Union strategy document “The Common Agricultural Policy: 2023-27” (CAP), which still does not take into account the specificities of urban agriculture in the Union’s planned strategy for the development of sustainable agriculture [37].

The steps taken up to 2017 in Europe, socially focused and attempting to individualize planning policies towards moving away from solutions with limited influence zone, are summarised in a study by Barbora Duží, Bohumil Frantál and Marian Simon Rojo [38]. Other European achievements, such as those of COST Urban Agriculture Europe [39], have been continued in the form of the Online Atlas of Urban Agriculture, available on the COST website [40]. A study of farm business models in Spain, Italy, and Germany reveals the shift from traditional collective urban farms to new commercial models impacting urban areas [29].

None of the directions of urban agriculture in Europe currently address the issue of the superstructure of existing facilities. Studies conducted recently on the development of vertical extensions, in most cases only of residential buildings, include an analysis of strategies and technical solutions only for urban-service functions and increasing the intensity of residential development in the centres of European cities [41–43]. They do not deal with allocating such extensions for urban indoor agriculture and other agricultural greenery. This remains the domain of practical, commercial action in urban space.

Studies carried out in the Netherlands and Belgium show that greenhouse horticulture, although functionally linked to agriculture, is often found in suburban areas, blending in with typically urban developments [32]. Hence, the conviction of some researchers, even before the appearance of the first large-scale implementation of urban rooftop gardening, is that this is the form most likely to link the rural and urban character of urban space [31]. Greenhouses appear to be a promising form of urban agriculture implementation [44]. The last decade has shown that they were right. This has been evidenced by the form of the buildings being examined in this study. So far, the greenhouses found in the city have also been a symptom of the urban sprawl phenomenon since, as a method of increasing food production and extending growing times, they have appeared on the fringes of cities in well-communicated areas [32]. However, the same researchers point out that, with the implementation of sustainable development principles and the change in greenhouse production technology, they have become a method for significantly reducing agricultural water demand, as observed in areas with unfavourable climates, such as in Israel and Almeria [45].

Studies in Almeria have also shown a local trend of a 0.3°C reduction in temperature per decade due to a significant number of greenhouses in the area [46, 47]. Although there are no studies confirming the same phenomenon for rooftop greenhouse solutions, the possibility seems so interesting that the first facilities have already been set up to experimentally test integrated rooftop greenhouses (iRTG) in the process of regular operation [48]. Studies show that in the future, greenhouses are willing to shift from being energy consumers to becoming one of the leading electricity producers, at least in the case of those surveyed from Denmark [32, 49].

Previous research has revealed another important problem in the presence of greenhouses in urban and peri-urban areas. Research by Elke Rogge has shown that greenhouses have a significant visual impact on the landscape, perceived as unfavourable [50, 51] and that their location adjacent to urban areas creates functional and social conflicts [51, 52]. The typical large-scale greenhouse form, higher, more extensive and much more dominant than the surrounding buildings, is perceived as not fitting seamlessly into the landscape. In his research, Van den Berg describes the area between Rotterdam, The Hague, Zoetermeer and Delft as “a rural-urban no-mans land” [52], echoing the residents’ general dislike of this form of development, resulting in the considerable anonymity of the space and the depopulation of relatively large areas (with a large cultivated area, the number of workers is minimal and access for the public is significantly limited).

Hence, in some countries, such as Denmark and the Netherlands, there has been conscious governmental support in converting peri-urban greenhouse areas into housing estates and, at the same time, “clearing” the landscape [32], which, however, required not only legislative but above all financial support. Experiences from the last 50 years show that having greenhouses in urban areas is beneficial despite risks. Recent studies focus on minimizing the impact of large greenhouses in cities by considering technological advancements and urban functionality [51].

Therefore, from a combination of benefits – the reduction in water demand, the introduction of renewable energy sources as a method of power supply, and technological advances in production methods – the only problem to be solved is the demand for peri-urban land that might otherwise not be developed at all or used for more strategic functions. The solution to this problem is to use the rooftops of buildings, mainly industrial, for building greenhouses, which already have their road infrastructure, access to utilities, etc., and therefore whose further use does not result in the development of unfavourable spatial and social phenomena.

Studies have been published for more than a decade now, confirming the positive economic, socio-cultural, and ecological impact of urban agriculture on space, especially in former industrial areas [36, 53]. So far, however, the architectural and spatial dimension of the activities conducted in this way has not yet been analyzed, most likely mainly due to the lack of permanent, rather than merely seasonal, developed spatial forms. The research that was conducted focused on the United States [54], although references to Italy (Catania) can also be found [55]. An analysis of the activities (mainly developed as bottom-up community initiatives) undertaken in the “Querbeet Hörde – Harvest your City!” programme as part of the process of revitalizing the post-industrial district of Dortmund Hörde in the Ruhr area revealed several specific objectives, which in this case were intended to act as a catalyst for the process [36].

Urban regeneration is associated in research with the concept of urban vacant land, especially in those areas in Europe where the intensity of development and the amount of historic fabric is most significant and significantly exceeds the potential availability of undeveloped sites [56]. However, the authors of the 2016 study mainly point to the role of temporary development versus agricultural function as a stage between the absence of function and the permanent development of spaces or facilities. Since then, the approach to the role of urban agriculture in urban space transformation has changed considerably. It is worth mentioning, however, that this research has, for the first time, highlighted the potential of areas defined as abandoned neighbourhoods, i.e. areas associated with the decline of an industry in a mainly suburban area, which is challenging to adapt and susceptible to a process of reurbanization, drawing attention to the example of Detroit and the grassroots initiatives already described in the literature [57].

Recent research points to the importance of adapting wasteland spaces on rooftops for urban agriculture [58], although in the case of Kyle Adrade’s research, this aspect was only described theoretically. Contemporary research is already clearly referring to the need for integrated action in urban space regeneration processes by integrating with urban agriculture to create “sustainable, equitable, and resilient communities, which will be critical as we face the climate challenges ahead” [59], but not as a method of mechanically fixing broken space, but a process of transformation designed for each situation.

The first of the analyzed cases was developed as part of a complex process of revitalization of the Cureghem district in Anderlecht. Its focal point is transforming a closed area of the still partially functioning municipal slaughterhouse into a multifunctional complex of residential and commercial developments linked to agricultural production and trade [11].

5.1.1.

Urban structure

NV Abattoirs et Marchés d’Anderlecht-Cureghem was a complex of peri-urban slaughterhouses combined with a meat and cattle market. The choice of this area was influenced primarily by its location, enabling it to reduce the nuisance of transporting cattle through the city streets. The navigable canal and the Western Railway Station, built in 1872 in Cureghem, allowed for efficient and relatively unobtrusive transport of animals to the area. It was not until 1888 that the city of Anderlecht permitted the construction of a new slaughterhouse and cattle market. The complex was designed by Adolphe and Guillaume Charlet, Emile Pierret, Emile Tiron and Henri Chevalier. The main entrance was built in the years 1901-2, according to a design by Henri Rieck.

The entire site originally covered an area of 20 ha (it has now been reduced to around 10 ha). The main preserved cattle market building took the form of a roofed hall measuring 100x100m, constructed in an arched cast-iron structure in the middle of the complex [11]. The slaughterhouse building was erected directly behind the market, along with the railway station and animal housing area. The complex administration was housed in a representative building on the side of the entrance square. The complex has survived despite plans to demolish most of the industrial buildings in Cureghem and replace them with social housing as early as the 1950s due to its considerable profitability. As a result, however, it was gradually surrounded by quartered buildings with an irregular grid.

The demand to modernize the premise, which with increasing urbanization was surrounded by residential and commercial developments, often chaotic, was mainly driven by the need to transform a foreclosed area, providing the opportunity to implement a range of social activities in an emblematic place for the neighbourhood. Within the framework of the FEDER-EFRO programme, the decision was made to build a new public market hall that would provide retail trade by 2013 without removing the slaughterhouse function. The Abbatoir 2020 masterplan envisaged a gradual transformation of the site from an industrial, enclosed area to an open area that serves the local community and is an important part of the urban tissue of Cureghem [12].

The main hall has been transformed into a multifunctional retail and exhibition space that is publicly accessible and suitable for temporary cultural and commercial events. The open-plan form of the historic building itself facilitates this. The general plan was to establish a public zone here by introducing complementary buildings and by intentionally creating a new function based on the existing one. The designed urban interior encloses and completes the 4 quarters separated by a public zone in its north-western part, on the side of the historical main entrance. The three market hall buildings in the design form the square’s northern wall. The plan also includes the construction of the so-called North Market as a new development on the canal side.

What stands out in this concept is, for the first time, the conscious approach to the planned introduction of the agricultural function in the revitalization process and its association with commerce and human habitation. Already today, despite the implementation of only the first stages of the whole project, the quality of the living space has been significantly improved, if only because of the progressive aestheticization. The introduction of cultivated green space, both indoor and outdoor, in and on buildings that are lower than the surrounding ones makes it visible from the existing development. It adds value to a site that was previously just a paved square.

The concept for the site’s revitalization included phasing, allowing the area to function permanently and uninterruptedly as an urban slaughterhouse and market area, with a gradual transformation into a multifunctional complex and a transition from an enclosed area towards a public space. The binding element of the whole concept was the need to run a new model of communication support for the area by constructing a new metro station to handle the increasing number of inhabitants. Within the analyzed area, elements that are not only historically but also functionally valuable were recognized, creating a core element of the identity of the place, while the rest was progressively demolished (see Figure 3).

Figure 3.

Functional analysis of the area of the Anderlecht district, Cureghem within 1km of the Abattoir BIGH farm. Authors’ elaboration based on site research and [63]

In countries such as the Netherlands, France, Spain or the UK, the average surface of grown crops in a single greenhouse exceeds 3 ha. Due to the lack of average statistics about rooftop and indoor urban agriculture implementations presenting an average size of the cultivation area, only statistics relating to traditional intensive greenhouse agriculture can be referred to. Newly built, commercial greenhouses erected on the ground in suburban areas generally always have a surface area that exceeds the average and often exceeds ten times this value [51]. Meanwhile, only the Agrotopia greenhouse reaches a size close to the average in the country of creation. The rest of the facilities remain significantly smaller than the average size of commercial greenhouses (Table 6).

This demonstrates the experimental nature of the solutions currently being developed. The higher construction and adaptation costs concerning solutions not relevant to existing buildings make it necessary to reduce the overall construction costs, Which may cause the need to build a smaller farm.

The analysis of the aforementioned parameters also demonstrates the smaller size of existing roofs than the actual technological possibilities of creating farming greenhouses in cities. In each of the analyzed cases, one can also see the necessity to exclude part of the roof area for technical or technological reasons, which is not the case for greenhouses on the ground. The analyzed cases show a complementary, rather than a superior, agricultural function concerning the surrounding area, where the size of the cultivated area is conditioned by the demand of the settlement in question, and any surplus area or higher than implementable demand for crop production is achieved in a form other than a greenhouse.

In this case, the farm’s function is complementary to the revitalization process. There are no examples yet of an attempt to base the whole process directly on urban agriculture facilities, although this analysis has shown a vast potential for this, particularly in the European area.

Elevating the greenhouse element will allow the building’s ground floors to be opened for more socially accessible purposes. Requiring strict adherence to a technological and sanitary regime, horticultural or aquaponic production is elevated above the level of everyday use, causing the whole area to be opened up to local needs or to fulfil a primary production or distribution function.

The shift towards local distribution, i.e. the conversion of hubs of national importance to those serving the local community and available within walking or cycling distance, results in this function also becoming a social one, integrating the local community. The socially poorly perceived form of the greenhouse, being associated with an inaccessible space, is elevated above ground level and so is not as visible. It is surrounded by other functions (housing, services, retail) to domesticate it. At the same time, the raised greenhouse is perceived as greenery and so takes over, at least in part, the social and psychological role of traditional urban greenery. Building positive associations with the new function is also aimed at dispersing greenhouses in the city, which is facilitated by building them on top of existing roofs with an already set area.

Due to the assumed technological and sanitary requirements, the zone of public access in each of the analyzed cases is strictly defined and limited. The lack of direct access to the enclosed cultivation area is counterbalanced by providing a visual connection. In the case of Abattoir BIGH, it is a visual connection and access to a part of the growing containers, which are open and intended mainly for a community garden, and therefore, with access partially restricted. In the case of La Cité Maraîchère, a view limited to one storey is provided, and an area is set aside as an extension of the entrance zone intended for a local restaurant, which is therefore excluded from the regular use of the farm. The whole insight into the entire process of plant growth in a closed environment is provided in Agrotopia, with corridors surrounding the entire cultivation area and only the technical rooms partially excluded (see Figure 6).

Figure 6.

Accessibility analysis for selected cases. Authors’ elaboration

The new function is not better than other solutions, as each has its limitations, but this one ultimately realizes current needs, referring to renewal purposes. It makes it possible to achieve a multi-level space, elevating complementary functions beyond the utilitarian level. At the same time, this function plays an additional role, influencing the perception of the transformed area as more human-friendly, more accessible and more aesthetically pleasing, introducing a closed, orderly form of greenery visible from the level of the upper floors of the surrounding buildings. It is thus visible from the residential spaces that surround each point.

Its value to the modern city is represented in being an example of the integration of greenery and buildings in revitalization processes as part of the community revitalization efforts and a visible element of a vertical extension trend as one of the housing strategies of European cities. It can also become an element of the vertical extension trend – the most current idea for solving the density problem during revitalization processes in European cities.

Therefore, urban agriculture built both as a vertical extension of indoor farming created as a mixed-use development, has the potential to become the solution to the needs of urban dwellers shortly.

The analyzed examples show the growing potential of commercial or semi-commercial introduction of urban agriculture as a component of revitalization processes in European cities. They provide evidence of the possibility of using commercial-intensive urban agriculture in the programming of this process for problem areas with specific locations on the edge of the transitional zones of different urban functions. In this case, the main line of contact is the boundary between industrial and residential areas, which, over time, have begun to surround the former. It is also a method for complementing the primary functions in existing settlements, as shown by the example of La Cité Maraîchère (Table 7).