Towards a Sustainable Process of Conservation/Reuse of Built Cultural Heritage: A “Coevolutionary” Approach to Circular Economy in the Case of the Decommissioned Industrial Agricultural Consortium in the Corbetta, Metropolitan Area of Milan, Italy

Abstract

This paper aims to explore the potentialities and systemic relationships between the ‘regenerative’ process and ‘circular economy’ concept within the conservation and reuse of a built cultural heritage framework through contextualizing the concept of ‘process programming’ of the Preventive and Planned Conservation methodology. As a case study, it depicts a decommissioned industrial agricultural silo in Corbetta—a small historic city with its hinterland located in the protected Southern Milan Regional Agricultural Park. The context includes the industrial agricultural lands of the 20th century, together with historical water infrastructure, farmhouses, and the typical flora of the Lombardy region, all evidences of Corbetta’s rural archaeological values and the sophisticated material culture of its past collective production/economy system—the locus in which the silo was once one of the main productive symbols of Corbetta’s agricultural identity. Within such a complex and challenging context, this paper argues in favor of the constructive role of such a methodology in upholding circular economy principles within the process of conservation and reuse of the silo, highlighting its broader application of the ‘coevolution’ concept from a multidisciplinary long-term perspective.

1. Introduction

1.1. Conservation, Reuse and Circular Economy: Contemporary Questions and a Responsive Italian Method

Within the paradigm shift toward the contemporary concept of ‘development’ in more humanistic/ecological manners, a ‘regenerative’ process that improves public services and well-being by creating local benefits/values while forming green economies upholds the transition toward ‘circular economy.’ In the built environment, such a process advocates for the conservation, valorization, and reuse of cultural heritage as one of the keys to sustainable urban regeneration in which the economy signifies a long-term “circularization of processes” and aims at “reducing social and environmental externalities and greenhouse impacts, recognizing the central role of the relationships/synergies/symbioses” [1]. Nowadays, circular economy strategies in lead European cities are “stressing the role of territorial actors and synergies to deliver new services and products and sustainable, ‘circular’ production-consumption strategies, to boost sustainable economic growth while enhancing the environment and social benefit” [2] (p. 36).

In this debate, at the heart of valuing cultural heritage there is a long-term commitment to its protection and reuse in favor of local resilience, where reusing historical buildings has often been considered adapting to “an evolving environment and the related needs” [3] (p. 25). One can argue that conservation cannot help but accept “adaptive actions” or “a coevolutionary process”, in which the object adapts itself to the environmental changes conditioned by “the presence of a cultural object.” In that regard, preservation must be understood “in terms of safeguarding coevolutionary potentialities of cultural objects” [4]. The planning of such a process, thus, cannot help but shift from programming the evolving cultural object to programming the coevolutionary potentialities of the same object within its territorial context; meaning the planning should manage the preservation and optimization of the ‘coevolutive cycles’ of potentialities in a ‘long-term,’ in a way that one would not deny the probability of the other potentials in a current state or the future.

In this context, the Italian Preventive and Planned Conservation methodology, which was re-launched from Giovanni Urbani’s Planned Conservation, initially encompassed the idea of preventive conservation, and it was in concordance with the Italian development of planned conservation since 2000 and enforced by the Italian Cultural Heritage Framework Law in 2004. As a method for the ‘sustainable management of changes’ and of ‘systemic’ relations, the Preventive and Planned Conservation is “a long-term strategy of careful planning of uses and quality, information management, regular maintenance, and control of environmental factors” [5,6]. In this type of planning, all actions and strategies are deliberated to be ‘programmed’ in the systematic ‘management process’ to establish a ‘logical and responsible attitude’ for the efficient use of resources, particularly in putting “top-down and bottom-up approaches” together [5,7]. Thus, in the case of its successful implementation, this kind of strategy would be more ‘effective’ and ‘feasible’ in achieving coherent ‘multi-scale’ sustainability and could guarantee the sustainability of the conservation process, reuse, and valorization of built cultural heritage within the ‘comprehensiveness’ of the circular economy goals in an ever-changing world [7].

1.2. Intellectual Background of the Original Research and the Selection of the Case Study

This article is primarily based on the postdoctoral research of Dr. Rajabi, who has addressed the key question of how the recognition of abandoned built cultural heritage becomes a key factor in the sustainable process of protection, conservation, and reuse of such structures. The original postdoctoral research aimed at creating more inclusive criteria for the selection and recognition of abandoned built cultural heritage based on their ‘values system’ and an ‘authentic sense of place’ by/for their communities rather than solely recognizing the practical values and conditions of structures of cultural significance, in order to ensure the sustainability of the conservation and reuse process of such heritage. While the Italian Ministry of Culture has already identified more conventional criteria for the selection of project proposals for the recovery/reuse of abandoned built cultural heritage, with particular attention and reference to Global Goals such as SDGs with the aim of achieving environmental sustainability ‘results’, Dr. Rajabi’s research intended to highlight the importance of the sustainability of the ‘process’ of conservation and reuse, particularly by bringing to light the ‘process programming’ that can be effectively achieved by the Preventive and Planned Conservation methodology. This article, in particular, uses one of Dr. Rajabi’s case studies to explore the potentialities and systemic relationships that contextualizing the concept of ‘process programming’ of the Preventive and Planned Conservation methodology can regenerate, rather than presenting inclusive criteria for the recognition of abandoned built cultural heritage. The selected case is a decommissioned industrial agricultural consortium in Corbetta, a small historic city in the western metropolitan area of Milan.

1.3. Grain Silos and the Question of Conservation and Reuse

Industrial agricultural consortiums are a specific type of built cultural heritage, known as “collective grain storages” (ammassi granari collettivi), whose networks were managed by the local agricultural consortia during the Fascist era. Following WWII, such grain silos for collective storage remained instrumental for the efficiency of food supply chains. However, significant industrial development in Italy prompted migration from rural areas to industrial centers, leading to stagnation in agricultural activities and the obsolescence of many grain silo buildings around Italian territory. As a result, silos as such were decommissioned, leaving behind empty structures that presented for decades challenges regarding safety, maintenance, and land use. Such a phenomenon is also recognizable, perhaps with different timelines, all over the world, where the paradigm shift in the agricultural sector, its logistics, local to global transportation methods, and global market trends in general overshadowed the local requirements for traditional ways of collectively storing agricultural products.

Nevertheless, today, the challenge of abandoned silos presents a focal opportunity for different disciplines to engage in thoughtful dialogue and possible innovation strategies to make a positive contribution to different dimensions of sustainability and cultural narratives of their broader context [8,9]. As modern industrial heritage, these structures encompass historical, cultural, architectural, artistic, and technological values worthy of preservation [10]. Although their considerable size and specialized construction can complicate repurposing efforts, this complexity can also inspire creative approaches to revitalizing these spaces without significant interventions [11] and compensation for their integrity and authenticity [12]. In general, the recognition of the values of industrial heritage by competent authorities, for example toward their adaptive reuse, has already shown positive outcomes worldwide [13]. Nevertheless, in the case of silos, such recognition may pose more complicated questions because their value, for example as urban landmarks, has been questioned in comparison to the visibility of other historic counterparts within, for instance, the Italian dense territory, while in countries such as United States or Canada their values as landmarks or iconic elements of local history has been wildly accepted [14,15,16]. It is worth mentioning that within the European context, the Spanish network of grain silos, being originally similar to the Italian ones, has been recognized since 1980. Scholars such as Salamanca Cascos and Mateo Caballos have explored the conservation and adaptive reuse possibilities [17,18] of the Spanish grain silos, leading to more systematic funding and organizational involvement in their transformations [19].

Above all, the planning for their sustainable conservation and reuse simultaneously, as a comprehensive process, remains underdeveloped, as their stories of success or failure (at least in the Italian case) remind us of the different loads and priorities that have been put separately on their preservation and reuse by the authorities and actors involved within regional and/or national management systems. For instance, in the Italian context, only a few of the fascist era’s silos have been the subjects of local to national interest and outreach, even fewer have been granted legal protections, and unfortunately, none have undergone successful, comprehensive conservation and reuse processes.

Within such a fragile context of actions/interactions in the fields of decision making, planning, conservation, and reuse, this paper attempts to explore the Corbetta silo’s complex and challenging context as a conceptual laboratory to demonstrate the constructive role of Preventive and Planned Conservation in upholding circular economy principles within the possible process of conservation and reuse, highlighting its broader application of the coevolution concept from a multidisciplinary long-term perspective.

2. Research Methodology

The original postdoctoral research selected a series of case studies of abandoned built cultural heritage of public ownership within the Lombardy region in Italy, starting from the database of the Ministry of Culture. Out of a total of 300 cases, a sample of 32 cases of abandoned properties was constructed, representative of their functional and formal program, chronological characteristics, size, and complexity, as well as their relation to the surrounding context. After conducting a preliminary study on the 32 cases, which took into account not only the buildings themselves but also their broader contexts, a few case studies emblematic of their particular form of relationship with the most current themes of sustainability were studied in depth within a qualitative approach, one of which was the ex-industrial agricultural Consortium of Corbetta, the main subject of this paper.

Additionally, during the research, the Corbetta case benefited from an action research method aimed at enhancing the decision-making process by engaging participant observers in planning, acting, observing, and reflecting. That was made possible through the applied research collaboration between the municipality of Corbetta and the Department of ABC at Politecnico di Milano, under the responsibility and coordination of Prof. Stefano Della Torre, for the feasibility and sustainability study of the conservation and reuse process of the case.

Based on the study of the Corbetta case, this paper presents critical reflections on the decommissioned Consortium, toward its sustainable conservation and reuse planning and its relationship with the circular economy, local drivers, actors, and potential for the future. The paper is mainly organized in three sections. While the first section aims to highlight the historical significance and current condition of the Corbetta case and its context, the second section discusses the values system of the consortium and the compatibility of its design choices and reuse options. The final section of the paper, the conclusion, aims to reflect upon different aspects of the sustainability of the process of conservation and reuse, opening particular windows toward the different natures (sometimes even in a practical sense) of its envisioning and implementation. In this regard, the conclusion’s goal is to initiate further discussion rather than to comprehensively end the debate.

3. Industrial Agricultural Consortium of Corbetta and Its Context; Historical Significance and Current Situation

3.1. The City of Corbetta

Corbetta, as a small city, is rich with the memory of traditional agriculture celebrated by the architectural and artistic qualities of its historical villas and gardens [20], bearing witness to the prosperous landscape and the flourishing economic system of the land investments of the sixteenth-century market led by Gottardo Frisiani [21]. The city’s origins may date back to the Celtic age (8th century BC), with its village structure evolving significantly during Roman rule, primarily due to the construction of the Roman road from Mediolanum (Milan) to Novaria (Novara), which passed just north of the current historic center. Over the centuries, Corbetta played strategic geopolitical/geoeconomic roles closely linked to those of Milan, as it served as the head of a parish with a vast territory to the west of Milan and was involved in the defense of Milan until the 17th century. Moreover, the presence of extensive woodlands filled with valuable timber for construction coupled with the abundance of water from numerous springs and starting in the 15th century, vast agricultural lands led the city to become a privileged destination for the Milanese nobility to establish large properties for their holiday resorts, a period still evident in the numerous existing pleasure villas (ville di delizia) that emerged from the 17th century.

The first transformation of the city beyond its historical core occurred at the end of the 19th century with the introduction of the Gamba de legn route to Corbetta, initially horse-drawn and later converted to a steam tram, running along an east-west axis to ensure a direct connection between Milan and Turin. It was an historic extra-urban tram in Milan, dating back to 1878, when the concession deed for constructing a steam tramway between Milan and Magenta was signed. To this initial route, a branch of the line from Sedriano to Castano Primo was later added. Starting from Porta Magenta in Milan, the original branch continued to the city of Magenta by passing through the Corbetta (Figure 1a,b). In Corbetta, the line changed the urban blocks of a few noble villas, passing by the current Piazza Pierino Beretta, where some courtyard buildings stood historically (Figure 1c), and where the abandoned silo is now located. Such a transformation paved the way for the construction of modern buildings with specific rationalist architecture in Corbetta, including the industrial agricultural silo, while still preserving the characteristics of an important medieval village [20].

The changes in the city’s structure at the beginning of the 20th century, particularly following the First and Second World Wars, were accompanied by industrial development on the city’s outskirts and the construction of a dense grid layout characterized by rectangular urban blocks in the north-west area. However, a predominantly agricultural landscape remained in the east and south. That type of expansion led in turn to economic growth and a demographic increase in the city [22] more dependent on the automobile and personalization of commuting between Corbetta and Milan. This shift was one of the reasons why a new bus system introduced the exact location for the central station as the tram line in front of the silo and edge of Piazza Pierino Beretta, where the adjacent petrol station also introduced, marking the central location in the Piazza. That itself transformed the site from an open area in between the historic city and the silo to the small roundabout of the city’s transportation hub (Figure 2).

In recent decades, significant urban expansion has occurred to the north of the city along the modern road and railway connecting Milan and Corbetta to nearby Vittuone and Magenta, which resulted in increased suburban residential development. This change represents a notable shift from the early 1900s, when significant industries predominantly characterized the area. In contrast, the hinterland of Corbetta within the protected Southern Milan Regional Agricultural Park still includes the agricultural system with its historical water infrastructure, farmhouses (Cascina), and the typical flora of the Lombardy region, all present evidence of Corbetta’s rural archaeological values and the sophisticated material culture of its past collective production and economic system (Figure 3, Figure 4 and Figure 5).

3.2. The Industrial, Agricultural Consortium of Corbetta

The silo itself was constructed between 1938 and 1939 by the Cooperative Agricultural Consortium of Lodi-Milan-Pavia, under the framework of the Italian Fascist Regime’s corporate policy to control the entire grain supply chain, starting from the compulsory delivery of so-called collective grain storage warehouses (ammassi granari collettivi) [23,24]. In a few years, silos and warehouses of various sizes and types rapidly multiplied across Italy and its colonies. Agricultural consortiums initially emerged in Italy during the mid-19th century as a response to changing agricultural conditions and the broader process of European industrial development. Those changes compelled agricultural workers to find new ways to protect their interests, creating representative bodies known as Comizi Agrari, which functioned at both the provincial and municipal levels. Such organizations laid the foundation for the first true agricultural consortia. In 1892, the Italian Federation of Agricultural Association (Federazione Italiana dei Consorzi Agrari, or Federconsorzi) in Paicenza [25], and later in Lombardy, the Agricultural Consortium of Pavia and Lodi Agricultural Cooperative Consortium were established [26]. Federconsorzi primarily aimed at reducing intermediaries between producers and consumers and supporting the social, cultural, and economic activities of agricultural workers through the control of production and distribution of crops, their collective storage and sales, and the scientific research and publications for the training of the workers [19,25,26].

Nevertheless, the first challenge to granaries emerged primarily from the industrial developments marked by a sharp decline in agricultural workers. Then, it flourished with mechanized and specialized agricultural enterprises, generating substantial cereals to satisfy market demands. This set of shifts necessitated effective long-term storage solutions. The fascist economic/agrarian policies of the 1920s (mainly based on autarchy (especially grain self-sufficiency), integral reclamation, and defense of land ownership) played a pivotal role in amplifying grain production, highlighting the urgent need to establish a comprehensive network of storage warehouses across the region, ensuring the effective management of storage and efficient distribution and conservation of the crops. By the early 1930s, the growing need for extensive and modern facilities to store significant quantities of grain in optimal conditions occurred to prevent overcrowding and overheating [19,27,28]. This situation led the agricultural consortia to enhance their equipment and design new suitable grain storage warehouses. Since 1936, silos had been systematically studied by engineers, architects, and leading construction companies, which marked the first opportunities in Italy for experimenting with and developing reinforced concrete for both agricultural and industrial facilities and Fascist monumental architecture [29,30].

In such a context, the first branches of collective storage warehouses were con-structed close to railways and tramways and, in particular, in southern Lombardy due to its prosperous agriculture, notably in the Lodi area, in Sant’Angelo Lodigiano, Melegnano, Gaggiano, Corbetta and in Milan itself. In particular, the Corbetta storage warehouse was a remarkable project by the Consorzio Agrario Cooperativo di Lodi-Milano-Pavia, based on a design by Lodi’s engineers Minoia and Asti (Figure 6). Its design was replicated with minor modifications between 1938 and 1939 for six additional facilities in Sant’Angelo Lodigiano, Paullo, Solaro, Desio, Gaggiano, and Corbetta. It bears similarities to the project by engineer Giuseppe Malinverno for the Provincial Agricultural Consortium of Como in Cernusco Lombardone, while its scheme resembles the Olgiate Molgora warehouse. Its architectural style showcases functionalist principles, featuring a fixed mechanical system as codified in technical literature [31]. Its main vertical component (the front tower), designed to accommodate the silo’s lifting system, not only exemplifies the resonating architectural composition with rationalist motifs favoring the current architectural regime but also characterizes the construction of the silos within a broader cultural policy promoting such ‘modernity’ in design (Figure 7).

The practice of concentrating products in agricultural consortia continued even after WWII, showcasing the centrality of storage warehouses in the daily practices of agricultural communities and their connection to local collective memories. Evolving from Ammassi Granari to Granai del Popolo (granaries of the people), their integration into the post-liberation economy marked a significant historical chapter of grain storage, contributing to discussions on the transition from the Fascist Regime to the Republic [24]. The cooperative foundations of agricultural consortia were supported through a set of measures and state incentives that, in turn, maintained cereal product stockpiling until the 1990s. Notably, there was a functional continuity linking these consortia to the agricultural practices of many families in the Italian countryside, which one can observe are still evident in the case of Corbetta.

Nonetheless, at the end of the twentieth century, the structure of the agricultural consortia in the whole Lombardy region underwent significant alteration, resulting in the abandonment of all grain storage warehouses. In the case of Corbetta, the storage warehouse was permanently decommissioned by 2006, yet unlike others of its kind, in the same year, it was declared as a “cultural interest” by Legislative Decree 42/2004 (Codice dei beni culturali e del paesaggio), and since then it has been protected under the criterion of “rural architecture of historical or ethno-anthropological interest as evidence of the traditional rural economy”. Interestingly enough, the overall decision to protect and the subsequent proposals for the requalification of silo were all influenced by a civic mobilization of citizens, local associations, and in particular the Committee for the Architectural and Environmental Defense of Corbetta. That was mainly due to their recognition of the silo’s significance in their collective memory. However, the debates surrounding the protection of the silo itself were more complex than they initially appeared. The main concern was not originally related to the Consortium and/or its protection and conservation, but the comprehensive redesign of the Piazza Pierino Beretta area and its relation to public transportation, influenced by the social and cultural values and intense economic pressures of that time. The decisive dialogue began in 2002 with the announcement of the Consortium’s decommissioning, the Municipality’s change to the PRG (Piano Regolatore Generale) and the designating of the Consortium area and adjacent Piazza Beretta as a zone for residential and tertiary redevelopment, which consequently led to a blending of public and private interests. Subsequently, a competition was held in 2004 to gather redevelopment ideas for the area. However, none of the proposals effectively integrated the Consortium into the overall logic of their design as an influential actuality. Finally, the efforts and purposes of the Committee for the Architectural and Environmental Defense of Corbetta extended beyond merely the protection of the Consortium itself, as the committee’s stance evolved to encompass a broader range of stakeholders. Thanks to the evolution of such local sensitivity, the conservation and reuse of this abandoned built cultural heritage have recently been under discussion between the Municipality of Corbetta and associated public and private entities/actors.

4. Discussion

4.1. The Values System of Industrial Agricultural Consortium of Corbetta

Despite the sheer number of grain silos and warehouses identified by archives and bibliographical sources (e.g., the archives of Federconsorzi, archives of the architect Cesare Scoccimarro, the manual of Chapperon in 1936, Italian Association for Industrial Archaeological Heritage (AIPAI)), only a minority of them still exist. Very few of them were reused, successfully or otherwise. In Lombardy, it is still possible to recognize a few of them, such as the Consortium of Corbetta, Paullo, Gaggiano, and Solaro (in the province of Milan), Desio (in Monza and Brianza Province), Sant’Angelo Lodigiano (in Lodi Province), and Cernusco Lombardone and Olgiate Molgora (in Lecco Province). It should be noted that Paullo, Desio, Sant’Angelo Lodigiano, Cernusco Lombardone, and Olgiate Molgora are all recognized as “cultural heritage” by being listed in the regional catalog of cultural heritage, and only the Consortium of Corbetta and Cernusco Lombardone have been declared of “cultural interest” by Italian law. Moreover, out of the eight Consortiums, three (Sant’Angelo Lodigiano, Paullo and Gaggiano) (Figure 8) have been partially or entirely demolished, three (Cernusco Lombardone, Olgiate Molgora and Solaro) (Figure 9) have been renovated/recovered into new functions via very dissimilar methods and with very different outcomes, and two (Desio and Corbetta) (Figure 8) have remained abandoned awaiting interventions. The warehouse of the Gaggiano Consortium has been demolished, preserving only the tower and its foreparts, while the Consortiums of Desio (not protected) and Corbetta (protected) are under the attention of the Municipal Administrations.

Among all those examples, the Consortium of Corbetta’s recognition and protection process has a unique storyline, particularly for its civic mobilization, which has not occurred in other contexts. Nevertheless, even in that case, the framework of values leading to the protection processes has been evolving from twenty years ago, when the discussion on the declaration of interest of the consortium was initiated, to today’s much more complex condition of rules and regulations for its conservation and reuse. In this regard, one of the first concerns could be related to the recognition of the values themselves for the protection of twentieth-century architecture, specifically rationalism or functionalism, less fortunate than those architectures whose significance has traditionally been attached to the importance of their authors/designers and/or have represented a significant manifestation in the evolutionary process of art. In the case of Corbetta, it is not surprising that at the beginning of the process of its protection, the competent offices of Soprintendenza deemed the silo irrelevant to the history of architecture; they believed that it was an anonymous building, the outcome of a negligible industrial and serial construction process.

Today, we may all agree that such traditional and rigid opinions do not capture the totality of the values considered in cultural evolution. Before being considered for their architectural value, industrial and agricultural consortiums were considered buildings of the production process, thus classified broadly as industrial heritage [32]. Such a process of recognition in Italy originally started with the first studies on grain silos by the Italian Association for Industrial Archaeological Heritage (AIPAI) [23]. Those studies led to a re-evaluation of grain silo architecture, revealing and appreciating the expressive values of similar buildings, including those associated with the Corbetta Consortium. In the particular case of Corbetta, the Committee for Environmental and Architectural Defense highlighted the city’s uniqueness concerning the memory of agriculture, which was first expressed through the architectural and artistic quality of the local noble villas [20] and then by the silo. This recognition process has encouraged the civic movement started by the Committee to gradually shift from merely architectural themes to a broader perspective known as industrial archaeology.

Unlike other similar examples in Lombardy, the Corbetta Agricultural Consortium is an entirely conserved example of essential industrial archaeology. It represents specific industrial/technological developments in the building construction techniques of reinforced concrete manifested in the most convenient layout/typology of grain silos. By its existence, the silo narrates the story of the collective past—perhaps not as aged as historic villas, yet just as effective. Furthermore, it serves as valuable testimony of the substantial political, economic, and social/cultural events/processes that have influenced the city of Corbetta since the early 20th century. Thus, one can argue that the significant testimonial value inherent in these types of silos in general and the Corbetta Consortium in particular needs to be stimulated, first and foremost, by the collective civic ownership of their memory; by local associations, communities and grassroots movements to help foster “self-protection practices” that in turn protect and enhance such cultural heritage without solely relying on the competent bodies and/or heritage experts [33].

In the past decades of the 21st century, the recognition of the values system and the protection of modern heritage has been a challenging topic since, in some countries like Italy, these practices continued to rely on the traditional approach and rigid evaluation system that appreciates mainly historical and artistic values. In Italy, such concerns primarily stem from the need to “expand the concept of cultural heritage” to include assets previously excluded from legal protection, specifically modern and contemporary heritage. Additionally, there has been growing recognition of values not traditionally acknowledged by law for twentieth-century heritage, such as the diachronic and testimonial ones. In that regard, according to SIRA (Società Italiana per il Restauro dell’Architettura), it is essential to “expand the exercise of protection policies” by activating the processes of identification and recognition of values by different communities—particularly local communities, competent communities, and heritage communities (with reference to the Faro Convention, 2005)—and by raising awareness and involving them in the protection processes. Also, they emphasize the importance of exploring dynamic, adaptable, and flexible tools that surpass the limitations of traditional and conventional “protection constraints”, fostering shared responsibilities and actively engaging the interested parties [34].

4.2. Compatibility of Design Choices and Reuse Options with Values System

After more than 20 years of legal protection but complete abandonment of Corbetta’s silo, in 2024, the Municipality of Corbetta took a significant step by acquiring its property. Finally, a meaningful discussion on its conservation and reuse is under way, with the involvement of culturally advanced public institutions like Politecnico di Milano as advisory bodies. In the following debates among different actors in the decision-making process, one of the main important points in reusing such heritage has been how to integrate conservation needs with the values system that is evolving over time. But more importantly, the main question to be answered has been about the managing of the preservation while optimizing the ‘coevolutive cycles’ of the potentialities of heritage in the long-term, or better, how to program the coevolutionary potentialities of such heritage within not only the silo’s values system but rather its territorial context.

Architecturally speaking, one of the first issues that has emerged in general discussion about the reuse of any agricultural or industrial silos is still associated with two contrasting perspectives. One is rooted in industrial archaeology, and the other is anchored in the traditional approach to asset protection as it pertains to architecture. Typically, the rationale behind industrial archaeology’s protection and restoration/reuse of structures such as the Corbetta Consortium differs slightly from that associated with Modern Movement architecture. While discussions about “Modern” architecture often prioritize the authorship of a design, the significance of industrial archaeology is tied to both archaeological and sentimental aspects related to the production process as well as the broader context of industrialization that extends beyond mere architectural considerations. Often, the traditional perspective appreciates the architectural and iconic values of, for instance, the image of industrial buildings. However, shifting to a different scale of values that acknowledges, for example, the history of technology, the collective memories of local communities, or memories formed around places of work is a notable challenge of our contemporary time.

In the case of grain storage warehouses, this difficulty in recognizing such values is evident in the decisions made, particularly regarding the front part of the building, which features a tower, pilasters, and portholes that reflect the rationalist style, in comparison to the functional rest of the building complex. For example, in the case of the Gaggiano Consortium, only the front portion of the building has remained, as the demolition of the Consortium’s warehouse appears to have occurred before any proper evaluation. Later on, various proposed projects for the redevelopment of the surrounding area have tended to incorporate the iconic remains of the Consortium without including the possibility to react to the original body of such industrial archaeology (Figure 10). In contrast, one can observe that the warehouse portion of the consortiums, as a pure utility and highly functional structure, is often preserved alongside the front part only if protection measures are implemented for the whole complex. This is evident in the case of the Corbetta and Desio Consortiums, while in the Cernusco Lombardone Consortium, only four of the eight existing warehouse bays were preserved, as the legal measures did not extend protection to the entire complex. After the imposition of the constraint by the officers of Soprintendenza, many authentic elements, including some elements of the mechanical system, were preserved while transforming the building into a restaurant. This initiative was undertaken as part of a private effort to create a shopping center featuring a significant volume of new construction. The preserved part of the Consortium is occupied entirely by the restaurant, recovering an upper floor in the side aisles. Less than a year after its opening, this function seems feasible, due to the location of the Consortium along a bustling road, yet it seems that at this moment, the upper floor of the building is occupied only on weekend evenings, indicating that expanding the space would have been unnecessary and economically unfeasible for the restaurant itself (Figure 11).

Globally speaking, at least since 2000, one can argue that the topic of silos and their cultural significance has gained attention worldwide, as many countries have shown a commitment to preserving these historical structures, even if repurposing them for daily use presents significant challenges. Numerous prominent port warehouses have been transformed in ways that adapt their use and reimagine them as powerful symbols of urban regeneration under the umbrella of “creative reuse” [19,30,35,36]. In Italy, after the pioneering case of the reconversion of the Pieve di Cento silo into an art museum in 2000, one can cite the cases of Livorno [37] and Genoa, where the Soprintendenza participated in the definition of the intervention program in full collaboration with local authorities and the port authority [38].

Nevertheless, looking at those examples, one can argue for the success of the reuse of cultural heritage and its essential linkage with the recognition of the values system, which occasionally and controversially has considered industrial heritage/industrial archaeology a “conflicting” heritage [39]. In that regard, industrial heritage’s cultural and historical values have been recently acknowledged, mainly thanks to the principles approved by ICOMOS for the Conservation of Industrial Heritage Sites, Structures, Areas and Landscapes in 2011. Among them, principles 9 and 10 are particularly relevant in this debate. Principle 9 highlights the application of the protection measures to the building and its contents, such as their machinery components, since “completeness or functional integrity [has been considered] essential to the significance of industrial heritage structures and sites”. Moreover, principle 10 emphasizes “the appropriate original or alternative and adaptive use” that is valued by ICOMOS as “often the most sustainable way of ensuring the conservation of industrial heritage sites or structures”, with the inclusive indication that the “new use should respect significant material, components, and patterns of circulation and activity.”

One can argue that such an approach fits well with the criteria that led to the Corbetta and Desio Consortium’s declaration as a “cultural interest”. That designation allowed adaptations aimed at sustainable reuse yet emphasized the importance of maintaining the building’s original identity and history; in the case of Corbetta in particular by preserving significant machinery that defined the fixed plant of the warehouse. Advocacy for the conservation of those mechanical elements themselves as agents of the building’s values system has opened doors to general consensus and the acceptance of more consistent adaptations for new functions. This approach ensures that vital components are preserved for future generations, allowing the building to continue playing an active role in the community’s future following the principles of “coevolutionary” reuse [40].

Nevertheless, as much as the success of the conservation of the Corbetta case is linked to the preservation of its technical values system, its effective reuse is also dependent on the extended set of values of the Consortium itself in relation to the city. Historically speaking, such a relationship can be found first in its symbolic role in the city’s industrialization and then, of course, in its historical productive and economic values for the agricultural society of the city, working-class families, and their patronage. As discussed before, those values are somehow self-evident in the building itself, both formally and functionally. Yet, its extended values system for Corbetta’s contemporary society is not immediately apparent, at least not until one examines the territorial context within which the silo stands. The agricultural sector of hinterland Corbetta, unlike lots of similar cases in the metropolitan area of Milan, is to a reasonable extent resistant to the suburbanization of the hinterland during the last five decades of Milan’s sprawl extension. This can be credited to, among other factors, the protection measures related to the Southern Milan Regional Agricultural Park, which limited the consumption or alteration of virgin lands around Corbetta. More significant is the agricultural society of Corbetta itself, which still functions even with the considerable impact of the 21st-century immigration. Out of 28 historic farmhouses (Cascina) located within Corbetta’s municipal boundary, only one is in bad shape or crisis in relation to its functionality. Moreover, Corbetta’s complex of modern agriculture and its set of individual agricultural structures are still active, all the more evidence of the richness and vitality of this sector of Corbetta’s contemporary daily life. To those, one can add the enormous possibilities that new agricultural technologies, smart agriculture, and urban farming can provide a new society in Corbetta, beyond the existing industrial farming and villa gardens (Figure 12).

Another potential factor can be found within the urban formation of the city itself, where to the north, it is limited by a parallel east-west line of road and railway, to the west by the vicinity of Magenta, and all other directions by the ring road, primarily defining the limits of the city with the agricultural fields. At the heart of all of this stands the silo, from which one can, with a five-to-ten-minute walk, reach to the southern edge of the historic core of the city and its famous villas, to the north the train station, to the west a suburban shopping complex shared in between Corbetta and Magenta, and to the east the agricultural fields. Almost all of the hinterlands are accessible by slow mobility, within (for example) the radius of a fifteen-minute bicycle ride (Figure 13). This high ease of accessibility and slow mobility can be one of the desirable features used to promote any urban regenerative project, guaranteeing that the site will have a proper network of accessibility to all the facilities and the communities of its extended context.

In those regards, it was not too surprising when the new PGT of Corbetta, in 2020, declared silo’s area as the “the zone of interest for urban regeneration”. The possibility of opening new public-private interaction and cooperation was particularly foreseeable if one saw the Consortium’s structure not only for its individual capacity to host a regeneration process via new functions and programs but also within its instance context, its relationships, and its future potential with regard to the currently less than sophisticated and poorly organized Piazza Pierino Beretta. One can argue that, if devised together, they can complement each other as the benchmarks of the historical, modern, and contemporary city of Corbetta. Once again, the place where the main tram and bus stations were located could be revived as the new gate, this time to allow the silo to become a new social and economic core of the relationships between future techno-agricultural society and the old traditions of Corbetta agriculture. In this sense, the silo could serve as a center for the local co-production and co-creation of societal values, for instance, including slow- or agri-tourism, or co-branding/sales of local bio or 0-km products as a constructive alternative to the passive culture of consumption of suburbs dependent heavily on the chain stores and processed foods.

Last but not least, one can argue that looking into the question of conservation and reuse of a case such as the Corbetta silo highlights the need to combine different methodologies to support the process of regeneration and revitalization of such a built structure together with its context and for its inclusive locals. Beyond the extended stakeholder analysis and value assessment of social and environmental sustainability and a cost-benefit analysis of economic sustainability, a more comprehensive planned multi-criteria analysis is vital before and during the decision-making process. The aim of the analysis should be to define the culturally proactive proportionally loaded steps before everything, to involve the public, interested and competent societies, and local experts, and to raise awareness and thus co-create proper demands and participations in peri- to post- events of conservation and reuse. Within a feedback system, this process in turn could give meaningful insights to balancing out the more convenient and feasible choices with the less evident yet more socially and culturally validated alternatives.

5. Conclusions

As previously discussed, the planning/programming of the process of conservation under the Preventive and Planned Conservation methodology, should be able to manage the preservation and optimization of the coevolutive cycles of potentialities of a building within its territorial context. In other words, it needs to strategically manage the transformations and systemic relations within the long-term vision of coevolution, in which maintaining heritage as ‘active and interactive’ with an ever-changing world can provide fertile ground to address extended circular economy goals. The successful implementation of such strategic programming, in turn, can guarantee the sustainability of the process of conservation and reuse of cultural heritage.

As Fusco Girard and Gravagnuolo explain, the circular economy model as such should exploit “synergies in the business/financing sector, in the social, cultural and institutional dimension through innovative public-private-civic partnerships for the management of commons, and environmental synergies through adaptive reuse of buildings and landscapes, of their embodied energy and local materials” [2]. This very much resonates with the potential and availability that exist in the case of the Corbetta Consortium. As an example of abandoned built cultural heritage of today, within this perspective, it is seen as a strategic resource to prove that successful conservation and reuse can foster sustainable redevelopment beyond the conserved building toward its extended territory of action and interaction with past, present, and future.

In this sense, the silo under exploration in this article should also be considered as the subject of innovative practices for defining its program. This is the frame in which sustainability is not simply a general reference but comes into action through some choices oriented toward at least financial and environmental efficiency. Actually, the business plan for the reuse of the silo has to take into account not only the costs of the works, which may be expensive, but also its running costs and revenues. If a kind of function has been identified looking at the benefits for the local system, the technical solutions which could be applied should reduce both the running costs and the environmental impact.

A good example of this approach could be found in the idea of adopting renewable sources in the case of the Corbetta silo. The extensive south-looking pitched roof of the warehouse is naturally a suitable place for a considerable surface of technological solar tiles. These days, such products are easily available locally, prototyped after a European project, and they have already been successfully tested on the historic campus of the Politecnico di Milano, allowing their use for similar built cultural heritage in Lombardy. A typical cognitive image of roofs with solar panels may have been seen as invasive to the heritage’s picturesque recognitions, yet the newly available solar tiles are hardly recognizable by viewers of a townscape. Therefore, their impact on the urban landscape is very much negligible. On the other hand, as mentioned before, the presence of innovative technological devices is perfectly consistent with the spirit of the place itself, protected not for its architectural values but as a 20th-century monument of technological innovation in agriculture. At the same time, the program of utilizing the roof of the silo for solar harvesting foresees the feasible balance of energy production and consumption. In a few years, the cost of the technological roof will be fully compensated, and the running costs of the building will be dramatically reduced. Given the recognized values, the characteristics of the building, and its recent history of contested protection, the Corbetta Consortium could be a perfect case for testing innovative solutions as such, showcasing the benefits of a multi-purpose reuse design.

To establish the silo as a new social and economic heart of Corbetta that connects, for example, the future techno-agricultural society with the traditional practices of the agriculture of the city, one can draw inspiration from similar innovative incorporations of hybrid programming of new daily use functions already tested in Lombardy region to address the challenges of green and digital transitions. For example, the overall plan on the ground floor for the silo’s warehouse, based on its spacious interior linear composition, its structural integrity, and its perpendicular direct connection with the adjacent piazza, can include a commercial function, co-created/managed by a local society specializing in local agriculture and food system processing, while the upper side floors can feature usable areas for a research/coworking hub dedicated to future investigations of smart agriculture in collaboration and partnership with schools, universities, and small/medium-sized enterprises specializing in new technologies. In this way, the ordinary and semi-public timetable of the ground floor would be complemented by the more temporary and occasional calendar of individual or group activities. While the ground brought economic vitality to the rescue project and engaged in a dialogue between the vendors and producers toward the co-creation of values, the first floor would promote agriculture’s new cultural and technological advancements by hosting and sharing local and regional expertise with interested groups. Thus, the program of both floors could go through a planned coevolutive process while constructively contributing to the conservation of the building itself.

To those, one can add the future possibility of associating the programs of both floors with the existing network of more traditional agricultural fields/Cascina around Corbetta, which are easily accessible within five to ten minutes via slow mobility. The new extended network of learning and adapting strategies, tools, and techniques within the hybrid programming of the new daily use functions, aimed at both ends of this collaboration, could then hope to fully activate the new techno-agricultural society of Corbetta. Last but not least, the front portion of the silo, the machinery tower with its representative architectural features, could host the more classic museology aspect of the memory of the consortium in the administrative office. All of this together, planned within a long-term vision with different timelines, functions, and target groups, would provide the whole building with a more inclusive notion of reuse and conservation.

In conclusion, investments in the planning phase of such complex abandoned buildings prove to be effective, as the research of up-to-date solutions consistent with the set of values recognized in the historic building and the territory helps to design changes which will keep the historic building alive and influential on the future of its context. In the case of Corbetta, the hope exists that with the constant involvement and demand of the local communities to preserve while living the memory of their past with their future generations, advisory bodies such as Politecnico di Milano could help to provide them with a better consensus of programs and processes as well as feasible alternatives for the future of their built cultural heritage.