Epilogue: Pragmatism for the polycrisis

It has been more than 60 years since John Habraken released “Supports: An Alternative to Mass Housing,” first published in Dutch in 1961 as De dragers en de mensen: het einde van de massawoningbouw – a slim book with profound implications for the field of architecture and a foundational text for open building. This special issue considers the future of pen building as a growing movement offering pragmatic innovations throughout the building lifecycle – from the basis of design to how a building is occupied and adapts to changing needs through time. Two years after the passing of John Habraken, this special issue is a snapshot of how open building has been reinterpreted within a widening field of scholars and with a growing number of built examples to learn from.Open House International was founded by Nicholas Wilkinson, one of Habraken's early students, and from its inception the journal has taken an interdisciplinary approach encompassing architecture, building technology, housing, urban design and planning. The articles within this special issue demonstrate the expanding influence of the principles proposed by Habraken. The resulting built projects and scholarship have been motivated by a growing range of concerns and put to the test in diverse contexts by Habraken's students, colleagues and successors during more than 4 decades of building and learning.In this editorial, I consider the view ahead for open building, a movement that has been a source of ongoing inspiration and challenge for the architecture, engineering and construction industry. I approach this task with the confidence that we are still in the early days for open building and that demonstrated open building concepts can point a way forward for an industry struggling to operate amid increasing market uncertainty and technical upheavals. If I were to speculate about the built forms that open building will take in the future, I would likely be wrong. Instead, I take this opportunity to consider how open building's successes, based on well-studied attributes, imply the necessity of systemic changes for the field of architecture if we are to see these ideas applied at scale towards more adaptive, yet long-lived, built environments. Open building is commonly explained as a method of disentangling the layers in the built environment based on their rate of change – a configuration for independent units within an enduring base building. Research in the field has long focused on the technical challenges of base building configurations, ensuring that decisions for individual units can occur independently, without disrupting other occupancies or shared building services. While the degree of system flexibility must be balanced on a case-by-case basis to avoid waste or limitation, these technical aspects are now well understood. Yet, architectural and engineering design is only a first move. Open building implies reconceptualizing the entire building lifecycle and a shift in focus to the immaterial aspects of the profession: project management structures, decision-making processes, occupant rights and legal frameworks that govern ownership and changes to the units. When applied at scale, open building stands to change almost everything about how we conceive, design, finance, construct and manage the built environment.At the foundation of open building was the often-cited disenfranchisement of building occupants within post-war public housing. Habraken supports both critiques of post-war housing structures and proposes approaches relating to the two spheres of action in building – the sphere of the commons and that of the individual. As a founding concern, the exclusion of the occupant interests from the decision-making processes in housing has found a successful remedy in open building, as evidenced through the operational histories of many built examples that account for vibrant and ongoing change processes for individual dwellings, such as Frans van der Werf's 1977 housing project Molenvliet in Papendrecht, the Netherlands. The Molenvliet project evidences the success of the support and infill concept, in this regard allowing for occupant involvement in the design and development of their homes in a way that is compatible with urban settings. Further details of the Molenvliet project are provided in van der Werf's excellent book Open Design in Practice (van der Werf, 2026). Recent projects, including two buildings designed by Frantzen and Kruit (2026) and developed by Lemniskade BV are profiled in this issue in Frantzen's article co-authored with Kruit, Patch22 vs Top-Up, a comparative case study of two open buildings. Their study demonstrates the freeing potentials of an open building approach to provide for individual agency while incorporating a wider understanding of sustainability in buildings that are designed for eventual program change while minimizing waste. Kendall (2026)'s contribution to this special issue, Open Building: a brief history and a look forward provides much-needed framing on the historical development of open buildings within distinct phases and his chronological overview of open building examples.Although it was the crisis in post-war housing and a loss of individual agency that prompted Habraken's critique and proposal in the form of open building, in recent years, new forces of change and motivations for open building practice have emerged. The challenges that architecture, engineering and construction, as an industry, must contend with today amount to a polycrisis: an entwined economic, environmental, social and geopolitical set of motivations to do things differently. A range of motivating concerns are reflected in the articles included in this special issue. In addition to the rigidity and disenfranchisement of top-down design processes, which played a pivotal role in the founding of open building, contributors address concerns such as the loss of architectural heritage, structural vulnerability and waste generation caused by discrepancies between a building's fixed configuration and the changing requirements of users. The authors also point to climate emergencies, high energy consumption, unanticipated health and safety demands, the inevitability of pedagogical shifts in education buildings and facility redundancy caused by demographic shifts. These factors, alongside the legal and economic barriers that hinder the future transformation of buildings, are identified as among the primary drivers for open building implementation.Clearly, open building as a formalized set of practices stands to address more than the shortcomings of hyperfunctionalist housing. By admitting different voices into the process of design, construction and occupancy, open building allows us to confront an industry blind spot: the reality that a building is not a static product but a time-based process. The technical understanding of how to accommodate change, for the fulfillment of the individual and a host of other motivations, is explored by several authors in this issue. Contributors including Aldemir and Özkuş (2026), Frantzen and Kruit (2026), Dale (2026) and Elguezabal et al. (2026) describe some of the varieties of configurations open buildings can take. Their studies are not limited to a discussion of technical matters. The entwined social, economic, political and legal implications of open building are key factors in the conception, realization and operation of buildings that are designed for change. As noted throughout the articles in this special issue, the technical attributes of open building – how to disentangle systems from the structure of the base building and ensure territorial autonomy – are now well understood. In many ways, open building is technically easy; however, adoption is legally and culturally difficult. The implementation of these ideas at scale requires a systemic restructuring of many aspects of our profession, not least of which are the immaterial ones: the legal frameworks, financial models and decision-making rights that govern the built environment.What appears initially to be an academically founded, theory-driven set of building practices becomes apparently much more. Despite the concentration of significant examples in the Netherlands, open building is not just a northern European rationalization. Open building stands to change almost everything about how we currently conceive, design, finance, construct and manage our buildings. In this ongoing and substantial reconceptualization of the field, open building presents a framework for accommodating continuous change in space utilization, technological integration and evolving building programs. As a spatial risk management structure, it is well suited for mitigating uncertainty in the built environment, as it can accommodate successive changes in response to both anticipated and evolving needs. For open building to be implemented at scale requires a restructuring of how we conceive, finance and manage the built environment. These changes are not primarily technical, nor are they stylistic. They amount to systemic changes for an architecture, engineering and construction industry that has seen lagging performance in productivity compared to other industries over the past 50 years and overall decreases in productivity since 2020 (McKinsey, 2024).When filtered through what I consider the three fundamental attributes of open building: (1) separation of roles, (2) territorial autonomy and (3) continuous and incremental change, we see that almost nothing about these three open building attributes aligns with AEC business-as-usual. These attributes describe a minimum open building approach, yet even this minimum definition of open building, when examined, provides insight into how open building implies systemic industry changes leading to more adaptive, yet long-lived, built environments. Each attribute implies a reworking of how buildings are conceived, financed, designed, constructed and managed around the world and across every market type. I briefly explore those implications for each of the three minimum open building attributes below.A separation or distribution of design tasks is fundamental to open building and is the logical extension of the technical delineation that occurs when a support structure is built to be independent from individual units. The separation of roles and design tasks implies dissolution of the sole-author myth that still permeates architectural education and practice. The support architects focus on urban coherence and long-term structural integrity, while the infill architects (or associated infill industries) address the more immediate and shifting needs of occupants. Aldemir and Özkuş's (2026) article, Modularity in transition: reconciling open building principles with early design education, demonstrates how open building-focused design studios can help develop systems thinking, awareness of a succession of programs and a productive exploration of tensions between industrial standardization and participatory flexibility. If we accept that different building layers have different rates of change, an enduring building will naturally be shaped by different professionals at different times. Explicitly separating design roles challenges the industry to put aside the manufacturing-inspired vertical integration tendency in favor of distributed intelligence and a plurality of contributing voices from the outset. In the intensely hierarchical and highly financially leveraged activity of a building, separating design tasks gives occupants empowering means of exerting influence. With the separation of roles and design tasks, different models of project financing are suggested and not only during the initial construction but throughout the building lifecycle. The design of both Patch22 and the top-up projects is discussed in the Frantzen and Kruit (2026) article, with specific attention given to the considerations that provided for flexibility in legal matters and ownership contracts. When the separation of roles occurs, there is also the clear understanding that future management and maintenance of occupancies can occur independently of one another.Importantly for the future adoption of open building practice, the separation of roles creates the market conditions for a dedicated infill industry – a supply chain of fit-out components that has been slow to develop but is now accelerating due to the substantial quality gains, customization potentials and speed that offsite construction offers. The KUBIK project, discussed by Elguezabal et al. (2026) in this issue, explores this potential within a research and development framework utilizing the architectural infrastructure provided by a test-bed building to experiment with interchangeable components. KUBIK demonstrates how separating tasks drives innovation in design and energy efficiency.Conventionally, buildings are a web of entangled systems – shared utility routes that are accessed only through adjacent spaces and rigid HVAC loops – rendering the occupants' desire for customization or change subject to complicated arrangements that often present hard barriers to change or else require extensive disruption to adjacent units. In open building, territorial autonomy is established in the design of the base building with configurations that allow the systems of individual units to be routed in ways that do not produce system clashes. Raised floors are often used to achieve this; however, other configurations such as service trenches and dedicated risers, raceways and wall systems can also be used to define service routes within separate occupancies. In operations, this means that mechanical, electrical and plumbing systems can all be routed, maintained and reconfigured without impinging on adjacent spaces. Although straightforward sounding, territorial autonomy for individual units results in a number of other freeing disentanglements that range from increased potentials for change and expression within units to the testing of new building technologies to optimize energy use. Although technical in nature and with a great variety of possible configurations and degrees of system flexibility and distribution across the units, territorial autonomy can be established in the design of the base building through a well-documented method known as capacity analysis (Kendall and Habraken, 2023). In an encouraging trend within adaptive reuse projects, territorial autonomy can be established when converting existing buildings. One misconception is that commercial office buildings are open buildings because of the high turnover and redesign of individual tenant spaces, yet few of these buildings have any significant degree of territorial autonomy. In such cases, layouts are highly constrained by the position of a vertical services core, and floor slabs are often penetrated by plumbing systems so that in the case of a leak or the need to reconfigure systems, any adjacent occupancies will need to provide access and will almost certainly be impacted by inevitable maintenance needs and layout changes.Maintenance processes and protocols within an open building are simplified because territorial autonomy means fewer conflicts, access issues and a faster way of isolating a problem that might otherwise impact adjacent units, such as a leak. This pragmatic approach in building systems engineering entails a shift from shared distribution to territories. Financially, this disentanglement allows for technical upgrades and a level of independent investment and control that has the potential to add equity to individual units. Risk-averse lenders may require that potential future use changes are recorded in the initial division deed. Open building also requires a reconsideration of flexibility in legal contracts and leases and the drawings that specify how a building is divided among owners, as well as how units can be combined or further subdivided.Open building implies that a project is never truly finished. To admit continuous and incremental change requires a new conception of success in architecture, one that values balance between permanence and incremental change. Continuous and incremental change necessitates adaptive ownership structures and property rights that recognize the separation of support and infill layers; it requires building codes that move from prescriptive to performance-based metrics, and it redefines user agency, transforming occupants from passive consumers to active participants in the design process. As Kendall (2026) notes in his article Open building: a brief history and a look forward, when we view the built environment as a time-based process rather than a static artifact, we must restructure our financing models to decouple the long-term investment of the support (depreciated over a century) from the shorter-term consumer financing of the infill (depreciated in 10–15 years). Correspondingly, innovation in financing and regulatory frameworks is required to facilitate buildings premised on continuous and incremental changes.Conventionally, a building's value is highest on the day the project is turned over to the owner, and it depreciates steadily as it drifts toward obsolescence. Open building stands to invert this depreciation model. The comparative analysis of Patch22 vs Top-Up by Frantzen and Kruit (2026) suggests that incorporating the potential for incremental future change – such as allowing a building to transition from residential to workplace – insulates investors and lenders against market volatility. Open buildings provide new possibilities for maintenance and management models, moving from reactive repairs to proactive facility management that anticipates replacement and facilitates parallel experimentation by different occupancies in the same building. By acknowledging that a building is never truly done, we move away from a crisis-response mode of devaluation leading to demolition toward a sustainable model of continuous adjustment and reinvestment. This model challenges us to move beyond hyperfunctionalist buildings based on prediction towards buildings that acknowledge the value of adaptive capacity as a means for a building to continuously change and blend with the forces of change.The industry's fixation on short-term financial returns has obscured the enormous value that comes from embracing, designing for and managing change processes. In open building, we have a framework for change management that is responsive to a range of driving motivations. As evidenced in the articles of this special issue, there is room enough within open building to pursue different aims – whether they be technological advancement, occupant agency or environmental resilience. As Amira Osman's work has explored, open building allows for ongoing user participation throughout the building lifecycle, rather than just the initial and often ineffective participation gestures at the start of a project (Osman, 2021). In this regard, open building's founding cause of restoring individual agency takes on a renewed importance as part of a reparative approach. Within a structure that welcomes change, we are afforded the space to try new ideas, to be wrong and to do so in an iterative, learning framework. This inclusivity equips us to address the constellated issues and forces of change that those involved in designing, building and managing our built environment must address. The continuing work of those in the open building community and the various uses and interpretations of open building principles demonstrated within this special issue return us, with renewed urgency, to Habraken's enduring objective: to make possible the creation of “districts which may grow old without becoming obsolete […] districts in which the population can live for generations, and which yet incorporate the potential for change” (Habraken, 1972).