Building Belief: The Urban Power of Physical Models and City-Making by Hand

Lessons from Portland’s City of Possibility and OHK’s international experience show why physical models still shape how we imagine place.

In an age dominated by digital renders, algorithmic masterplans, and fast-moving urban design tools, the physical architectural model can seem obsolete. But across continents and decades, OHK has found the opposite to be true. From economic zones in the Middle East to growth corridors in East Africa, we’ve seen firsthand how physical models remain essential tools for translating complexity into public understanding. Far from decorative or nostalgic, they serve as instruments of negotiation, clarity, and civic trust. What follows is both a reflection and a practical guide that explore that enduring value through Portland’s recent exhibition, City of Possibility, which showcased over 50 models spanning the city’s past, present, and speculative futures. OHK engaged with curators, contributed to public dialogue, and—drawing from our global experience—hosted a full-day workshop on model-making for urban planning. The session brought together students, practitioners, and city actors to explore how physical models can sharpen thinking, reveal conflict, and foster shared authorship of urban form. From tools to techniques, from philosophy to fabrication, what follows is both a reflection and a practical guide. Across it all, one theme remains constant: when cities are built by hand, possibility becomes visible—and shared.

Reading Time: 25 min.

Why Cities Still Need Physical Models: Lessons from Portland’s ‘City of Possibility’

Reclaiming the Civic Table—Cities are shaped by stories—some told in plans and permits, others in public memory and protest. But amid digital renders and remote planning sessions, one old tool is quietly reclaiming its power: the physical architectural model. Far from obsolete, the scale model is once again emerging as a civic medium—a tangible, spatially democratic format where people can gather around, see their city at once, and imagine it anew. And nowhere has this become more vivid in recent memory than in Portland’s landmark 2025 exhibition, City of Possibility. The OHK team was among those present during the opening weekend and follow-on programming—not just as observers, but as contributors to the broader dialogue around civic form, material imagination, and urban design practice. The exhibition didn’t just showcase Portland’s past; it offered a living conversation—one that OHK joined alongside peers, students, and city officials, affirming our shared belief in the enduring relevance of physical models.

More Than Representation: Why Physical Models Still Matter—In the age of high-speed rendering and AI-generated streetscapes, architectural discourse risks becoming more exclusive, abstract, and detached from lived reality. Screens allow rapid iteration, but they also fracture perspective: the architect sees one thing, the client another, the public perhaps nothing at all. Physical models, by contrast, create shared vision. They invite people—planners, students, and practitioners like OHK—to gather at eye level and encounter a city in miniature. During a curator-led tour attended by OHK and others, one key insight emerged: that models can "slow down" a city, making it not just visible but graspable in its complexity. As OHK’s Ahmed Al-Okelly noted during a panel discussion, “A model invites conversation across disciplines. A developer, a planner, and a resident can all stand around the same object and begin to co-author the future.” That kind of accessibility and co-presence simply doesn’t happen in digital-only spaces.

Portland’s Civic Reawakening Through Modelmaking

As part of OHK’s exploration of Portland’s preservation and exhibition models, the team engaged extensively with Norm Gholston, the Portland Architectural Heritage Center’s Preservation Programs Manager and the leading expert on its collection. Known as “the person with the most knowledge of the collection,” Gholston generously spent time walking OHK through their models and other relevant holdings and sharing his curatorial philosophy.

Gathered Forms: Portland’s Public Dialogue in Scale—That public, plural power was at the heart of City of Possibility, a two-month exhibition curated by PDX Design Collaborative, a local alliance of architects, artists, educators, and institutions. The exhibition launched in January 2025 and ran through March, activating two landmark buildings in downtown Portland: the Expensify Bank Building and the J.K. Gill Building. The concept was deceptively simple. As co-director Will Smith recalled in conversation during a walkthrough, the idea emerged from a question that felt disarmingly modest: “What if we invited everyone to bring the models they already had—and placed them on one big table?” This open, inclusive framework resonated with OHK’s own values of participatory design and plural civic memory. What followed was a uniquely Portland ensemble: more than 50 architectural models, contributed by over 40 architects, ranging from celebrated figures like Michael Graves and Pietro Belluschi to emerging ones like Jennifer Bonner, Waechter Architecture, and ZGF. The result was a living archive of ideas, tensions, dreams, and spatial propositions—precisely the kind of narrative tapestry that OHK engages with in our urban regeneration work.

The 1971 Downtown Model: A City’s Fir-Lined Blueprint—At the core of the exhibition stood a 12-by-18-foot model of Portland’s downtown—originally built in 1971 as a planning tool for the 1972 Downtown Plan. Meticulously crafted from local fir and loaned from the Architectural Heritage Center, the model was more than a historic object. It was a blueprint for urban intention—a diagram of values, priorities, and erasures. During OHK’s engagement, this model sparked a particularly rich exchange. We explored how similar models might support public housing dialogues in other cities, or how retroactive analysis of what wasn't built can inform present-day equity strategies. As OHK noted “This model doesn’t just show what was planned—it shows the silences, the spaces where community could have existed, but didn’t.”

Old Voices, New Visions—Beyond legacy figures, City of Possibility made space for contemporary experimentation. Modular housing studies by Waechter Architecture, mass-timber proposals by LEVER, and conceptual works like MALL’s Blank House created a multi-generational dialogue in form. OHK’s own reflections—shared informally with visitors and colleagues—centered on the possibilities of exporting such collaborative model exhibitions to other cities grappling with transformation: from Cairo’s downtown to Amman’s new business district. The curators’ approach—intentionally juxtaposing past and future, legacy and provocation—aligned with OHK’s principle of “temporal layering” in planning: designing not by erasing history, but by drawing it forward into future narratives.

Civic Practice as Curatorial Practice—One of the strongest aspects of the exhibition was its interdisciplinary curatorial team, bringing together academic voices from PSU and UO alongside practicing architects and civic leaders. The conversation turned to how such exhibitions can become tools not just for reflection, but for policy formation. The show’s public program of nine events further elevated this potential. At the Portland’s Next Horizon talk—hosted at the Portland Art Museum—OHK joined others in discussing how civic-scale design competitions might evolve if models like these were made public from the outset. “There’s no reason these models need to live in back offices,” the OHK team remarked. “They should be part of the public record—physical artifacts of a city’s self-reflection.”

Digital Isn’t Enough: The Case for Material Thinking—Throughout the exhibit, the tension between digital fluency and physical presence was palpable. On one table, a laser-cut tower model by a local firm stood next to a foam-core concept sculpted by hand. Both were compelling—but it was the tactility that drew people in. In discussions, OHK emphasized that the physical model is not a nostalgic tool. It’s a pedagogical one. It teaches constraints. It embodies decisions. It allows criticism to emerge from observation, not just theory. Digital tools have their place—OHK uses them extensively in infrastructure planning and resilience modeling. But as we reaffirmed during our time at City of Possibility, nothing replaces the collective gravity of people gathered around a model, talking about their city.

Looking Ahead: A Call for More Civic Modeling—If there’s one legacy OHK hopes this exhibition catalyzes, it’s a wider embrace of public model-making as a civic infrastructure. What Portland achieved in two buildings over two months could become a format replicated elsewhere: from Nairobi to New Orleans, Alexandria to San Francisco. Already, OHK is in discussion with regional partners about how similar exhibitions might be structured around themes like climate migration, green infrastructure, or urban affordability. The insight we took from Portland is clear: the model is the meeting place.

OHK’s Experience: Building Models Across Geographies and Contexts

At OHK, the value of physical modeling isn’t a recent revelation—it’s part of our practice DNA. Over the past two decades, we have designed and built scale models for a range of complex planning and infrastructure projects across Jordan, Saudi Arabia, the UAE, and most recently in East Africa. These models have served multiple purposes: visualizing national infrastructure corridors in arid desert regions, testing urban form in coastal zones vulnerable to climate change, and supporting stakeholder dialogue around green building incentives and zoning reform. In each context, the model became a mediator—translating between engineering schematics, planning codes, and the everyday questions of citizens and decision-makers alike.

This combined image above presents two distinct but complementary models of downtown Portland that serve different urban planning and architectural purposes. On the left, we see the Portland Downtown Scale Model, a large-scale wooden maquette. Made primarily of stained wood blocks, this model abstracts buildings into simplified volumes, emphasizing form, footprint, and massing rather than architectural detail. It covers a broad swath of the central city, including the Willamette River, major bridges like the Hawthorne and Morrison, and key downtown streets such as Yamhill, Alder, and Front. The tallest structure toward the center is the Wells Fargo Center and the U.S. Bancorp Tower (known as Big Pink), rendered in a darker wood tone to denote height and prominence. Lighter wood blocks often represent recent or proposed developments, signaling the evolving skyline. This type of model, usually built at a scale like 1:1000, is used by planners, architects, and the public to visualize density, shadow impacts, zoning proposals, and overall urban morphology. It prioritizes spatial relationships and urban logic over detail, making it a powerful civic tool.

In contrast, the right side of the image shows a highly detailed architectural model of a specific civic precinct in downtown Portland, focusing on the Portland Art Museum, the South Park Blocks, and the adjacent government or cultural buildings—the Multnomah County Central Library/Portland Center for the Performing Arts. This model features intricate landscape elements, street furniture, pedestrian paths, and even public art installations such as the reclining human figure in the park, reflecting actual sculptures in the Park Blocks. Made with plastic, foam, and textured materials, this model operates at a larger scale—likely around 1:100 or 1:200—allowing for the accurate representation of façade articulation, fenestration, tree species, and the human scale of urban life. The purpose here shifts from zoning and bulk massing to storytelling, public engagement, and design development. It communicates not just form but atmosphere, use, and lived experience—essential for projects undergoing public review or requiring stakeholder buy-in. Together, these models illustrate two layers of city-making: the left demonstrates the macro-scale of policy, infrastructure, and growth management, while the right zooms in on the micro-scale of civic identity, cultural memory, and public space design. Their contrasting materials and resolutions reflect their intended uses—wood for abstraction and strategic vision, plastic and vegetation modeling for emotional resonance and spatial specificity. Both are crucial in shaping a city of possibilities.

Lessons Learned from the Ground—From these engagements, we’ve seen how models shift the tone of high-stakes conversations. When working with government officials, a 3D model often breaks through institutional fatigue—allowing ministries and mayors to move beyond PDFs and PowerPoints into a space of spatial imagination. In cities like Amman or Mombasa, we’ve watched stakeholders physically lean in, pointing at terrain, tracing road alignments with their fingers, asking questions they hadn’t thought to ask before. As one planner in Tanzania put it while reviewing a regional model OHK created: “This is the first time I’ve seen the entire system in one frame.”

More Than Display: A Negotiation Tool—We’ve also learned that the process of making the model together—with engineers, urbanists, and local stakeholders at the table—can be as impactful as the final product. It builds ownership, surfaces constraints early, and supports more transparent decision-making. Whether presenting to heads of state or community councils, our experience has consistently reinforced this truth: a physical model opens space for negotiation rather than persuasion. It doesn’t ask people to agree with a finished vision—it invites them to shape it.

Making the Invisible Visible: Why Architectural Models Are Built

Architectural models have long served as the physical language of the design world—allowing architects, planners, clients, and the public to see, understand, and critique buildings and cities before they are built. Whether carved by hand or printed with lasers, models offer something plans and renders cannot: a shared, tangible representation of space. OHK led a hands-on workshop on how to build architectural models—sharing practical techniques, cross-regional experience, and lessons from working across contexts. The session invited students, urban professionals, and public officials to explore how material choices, fabrication methods, and design intent converge to shape not just form, but civic dialogue. The workshop emphasized that making models is not just about presentation—it’s about process, iteration, and collective clarity. The following write-up builds on that session and OHK’s broader expertise to explore how models are built today, the evolution of techniques, the range of materials used, and the hybrid processes that blend old-school craftsmanship with cutting-edge digital tools.

The Portland Building by Michael Graves—one of the most iconic examples of postmodern architecture—is shown above through its original design model (left) and the completed building in downtown Portland (right). The model reflects Graves’ playful yet structured approach, blending classical motifs with bold colors and symbolic forms. The realized structure, completed in 1982, remains a landmark of civic architecture, anchored by the dramatic Portlandia statue on its façade. Notably, OHK collaborated with the late Michael Graves on the early master planning and architectural design of El Gouna in Egypt, bringing his distinctive vision to an entirely different cultural and environmental context.

From Conceptual Sketches to Massing Studies: The Types of Models and What They Do

Conceptual models, massing models, detail models, and site context models each play different roles across the lifespan of a design project. Understanding the distinctions between them is essential, because the type of model you build deeply influences how your project is interpreted and who can engage with it. In the Renaissance, architects like Filippo Brunelleschi and Leonardo da Vinci built wood and wax models to visualize domes and mechanical systems before blueprints were standardized. By the 18th and 19th centuries, Beaux-Arts training emphasized plaster and wood models for academic presentation. The 20th century brought with it a functionalist turn: massing models became a staple of modernist practice, used by figures like Le Corbusier and Ludwig Mies van der Rohe to test urban geometries and structural purity. By the 1970s and 1980s, models became more expressive and material-rich, with architects like Aldo Rossi and Peter Eisenman using them to convey narrative, memory, and metaphor. In parallel, the rise of participatory planning introduced models as tools for public engagement and negotiation, not just presentation. In the digital age, physical models have become hybrid tools, often designed in CAD and fabricated by laser or 3D printer but still assembled and read by hand. The types of models differ by purpose and audience.

A conceptual model is often the first physical output of an idea. Usually abstract, these models emphasize form, spatial logic, or architectural principles over realistic proportion or technical accuracy. They are crafted quickly and experimentally, sometimes from found objects or rough materials, and their purpose is to provoke questions rather than answer them. At OHK, conceptual models are often used in early-stage dialogues with clients and city officials—not to suggest solutions, but to test frameworks. How could a water-sensitive urban design strategy look in section? What if housing blocks were clustered rather than linear? These models encourage free thinking. Some of the most influential architectural ideas of the last century began life as conceptual models. In 1924, Ludwig Mies van der Rohe’s model for the Brick Country House used simple planar forms to express new ideas about transparency, openness, and flow—decades before those terms became modernist clichés. Similarly, Le Corbusier’s early models for the Ville Radieuse were not meant to be built as-is but served to provoke urbanists to rethink density, hierarchy, and green space. In the 1960s, Italian radical architects like Superstudio and Archizoom used conceptual models as critiques of architecture itself—grids stretching endlessly across desert landscapes or mirrored megastructures imposed on rural fields. These models were often made from minimal materials—foam, mirrors, string—but carried huge intellectual weight. More recently, Zaha Hadid’s early conceptual studies for The Peak and the Cardiff Bay Opera House pushed the limits of formal abstraction. Her models didn’t just communicate geometry—they embodied movement, tension, and spatial possibility. In each case, the model was a provocation, not a proposal. It existed to ask: what if architecture were something else entirely? This legacy continues to inform how OHK uses conceptual models—not to answer questions, but to expand the field of inquiry.

Massing models, on the other hand, are about proportion and placement. They are volumetric studies that show how structures relate to each other in size, orientation, and density. Often built in neutral tones and without windows or façade details, these models help clients and city officials visualize scale without distraction. In OHK’s work on a coastal regeneration project in the Gulf, a series of massing models made it possible to debate where mid-rise buildings should give way to open space, or how much of the waterfront should be retained for public use. Historically, massing models have played a central role in shaping urban form—often before any design details are defined. One of the most iconic examples is the 1960s New York City Panorama, a room-sized model commissioned for the World’s Fair and built by Raymond Lester Associates. Though it included detail for exhibition purposes, it functioned first and foremost as a massing study—allowing planners to evaluate development across boroughs and to simulate future zoning impacts. In the 1970s, the London County Council maintained extensive foam and timber massing models of central London, which were used to review new proposals and assess their effect on skyline continuity, sunlight, and historical sightlines—especially around St. Paul’s Cathedral. More recently, OMA’s model for the Seattle Public Library began as a stack of extruded massings, arranged to reflect internal program blocks. This conceptual massing approach informed both form and function, helping guide structural and envelope development downstream. At the city scale, firms like Foster + Partners and BIG often use layered site massing models—especially when working in polycentric cities or waterfronts—to map volumes before ever deciding on typology or material. The model’s neutrality becomes its strength: it invites spatial reasoning without aesthetic bias.

Detail models zoom in. They are built to a larger scale, often 1:20 or 1:10, to show a façade system, roof junction, or even material layering. These models are especially useful in technical meetings or construction coordination. In one East African housing project, OHK used detail models to demonstrate passive ventilation strategies to local contractors and builders with minimal formal training. Seeing a section cut through a roof truss made the building logic intelligible—in a way drawings never could. Detail models have long been essential to bridging the gap between design concept and construction execution. One renowned early example is the Trinity Church in Boston by H.H. Richardson, where 19th-century artisans built scaled wooden details of its Romanesque arches and masonry joints to test fabrication techniques and stone tolerances. These models, made before mechanical drafting was standardized, allowed a close reading of structural interfaces that drawings couldn’t convey. In the 20th century, Bauhaus workshops routinely constructed large-scale detail models—particularly under Gropius and Hannes Meyer—as part of their pedagogical system. These models often isolated a single component, like a window jamb or stair tread, and taught students the relationship between material, geometry, and production. Later, firms like Renzo Piano Building Workshop developed finely crafted 1:20 and 1:10 models of the Menil Collection and the Jean-Marie Tjibaou Cultural Centre to study façade assembly, light diffusion, and layering systems—sometimes testing dozens of iterations in physical form before finalizing a design. Today, firms like Herzog & de Meuron continue this tradition, often producing entire mock-ups of envelope sections at large scale. These detail models do not just show how a building looks—they show how it breathes, drains, expands, and endures.

Site and context models are perhaps the most complex. They situate a project in its broader landscape—capturing topography, infrastructure, street networks, and neighboring buildings. These are the models most often used in planning commissions or public exhibitions. In these, OHK includes everything from planted trees to traffic flows, often incorporating removable layers to show phasing, zoning overlays, or risk zones such as flood plains. Site and context models have played a critical role in shaping urban decisions at both city and district scales. One of the most famous examples is the Chicago Model City, a sprawling 3D model of downtown Chicago housed in the Chicago Architecture Center. Continuously updated, it allows planners, developers, and citizens to see new proposals in real time—within the city’s real fabric. It has become both a tourist draw and a policy tool, consulted during zoning debates and visioning exercises. Earlier, in 20th-century Paris, the Atelier de Montrouge created layered plywood models to test housing developments within the dense, historic fabric of the Parisian suburbs. These models helped visualize new infrastructure alongside preserved landmarks, making abstract urbanism more comprehensible to both bureaucrats and residents. In recent decades, Tokyo’s massive 1:1000 city model, housed in the Mori Building Digital Art Museum, has served as a masterplanning tool—used to evaluate infrastructure, density patterns, and the visual impact of new towers. It offers a rare bird’s-eye synthesis of a hyper-dense metropolis. For OHK, such models are often modular—built with removable layers to allow project stakeholders to explore phasing, land use, mobility, and even hydrological risk. In these models, urban complexity becomes a tactile, shared reality.

Each model type carries its own logic. Together, they allow a project to move from intuition to iteration to implementation—with clarity and care.

Inside the Civic Imagination Table: A Day of Learning, Making, and Dialogue on Models with OHK

Setting the Scene—OHK hosted a civic-focused workshop on architectural model-making. Taking place in a central downtown space, the workshop was conceived not merely as a technical demonstration, but as a hands-on exploration of how physical models operate as instruments of dialogue and design translation. The setting itself added quiet resonance. Participants worked within sight of scale models from past and present, surrounded by the energy of architectural discourse and public imagination already in motion. The event welcomed a wide mix of attendees. The OHK team curated the day as a journey through model logic—a progression from theory to method, from material to message. While construction techniques and scale accuracy were central, the workshop constantly returned to bigger questions: Who is this model for? What does it need to reveal? What is gained—or lost—by showing form in this way? As one participant remarked midway through the day, “This isn’t just about craft. It’s about how you tell a story that cities can act on.”

On the left, OHK’s Ahmed Al-Okelly leads a model-based discussion during the Portland workshop, using a recently built massing model to illustrate spatial strategy and stakeholder alignment. On the right, a close-up of the same model reveals its precise volumetric logic—constructed from laser-cut basswood and chipboard to explore building heights, densities, and public space structure. Created for an urban regeneration project in East Africa, the model omits architectural detail to focus on core relationships between built form, street networks, and open space. Designed as a tool for early-stage planning dialogue, it helps municipalities and communities co-author a shared urban future.

Morning Session: The Model as Conversation—The day began with a brief welcome, followed by an introductory talk. Framed as a provocation rather than a lecture, this opening session set the tone: “We don’t make models to impress,” OHK noted. “We make them to invite questions, to slow things down, and to make ideas visible before they harden into contracts.” This was followed by a short visual presentation tracing the evolution of physical models across time—from early wooden section cuts in the 17th century to the political city models of the post-war era, and up to the hybrid-digital prototypes of the present. Alongside famous examples from Chicago, Tokyo, and Paris, OHK shared images of its own models built in Jordan, Saudi Arabia, and most recently in Tanzania—each chosen to demonstrate how physical form shaped government understanding and policy direction. The floor then opened for group discussion. Topics ranged from who model-making is really for to what happens when it’s absent. One attendee reflected that in her own agency, digital renders were standard, but “nobody walks away with a shared picture in their mind.” Others noted how model scale affects inclusion: a 1:1000 city model may suit planners, but a 1:20 detail might be more accessible to builders, craftspeople, or residents unfamiliar with design vocabulary.

Mid-Morning Activity: Building Form Without Facade—The first practical exercise of the day focused on massing models. Participants were given a shared urban block and asked to explore different volumetric solutions for housing, public space, and mixed-use development using white foam, chipboard, and stacking modules. Importantly, no surface detail was allowed—just mass, orientation, and site context. One team clustered small buildings around a central courtyard, while another placed a mid-rise ribbon along the street edge with setbacks for gardens. As they built, facilitators from OHK posed questions: What happens to light in this layout? Where does the wind move? What does the pedestrian feel here? Once assembled, the various iterations were placed side by side on a long table, and the room collectively assessed them. Without knowing architectural styles, materials, or branding, the models spoke volumes. Some schemes felt overbuilt, others too spare. The feedback wasn’t aesthetic—it was spatial. The group quickly realized that massing models are arguments in volume, not finished visions.

Lunchtime Panel: Models in Government and Practice—Lunch was paired with a panel-style conversation moderated by OHK and featuring voices from a city urban design officer, and a community housing advocate. Their shared topic was Models as Tools for Civic Alignment. The city official described how model absence had led to misinterpretations in a major rezoning process, where the public couldn’t picture the scale of proposed changes. “We had the data,” she said. “But not the shape of it.” The housing advocate noted how models helped shift conversations away from abstract NIMBY debates toward concrete questions like Where exactly is the courtyard? Is this lane wide enough for emergency vehicles? OHK’s representative spoke about a Jordan regional plan model built with modular, swappable zones to show how land use might shift over time with development and conservation agendas. “When ministers can physically remove a piece of the area and imagine what goes there instead, you get real buy-in. That’s where policy becomes plastic—in the best sense of the word.”

Afternoon Workshop: Materials, Machines, and the Urban Model as Process—The afternoon portion of the workshop transitioned into hands-on engagement with materials—but not with façades or trusses. Instead, the focus shifted to how urban-scale physical models are constructed in practice today: the tools involved, the types of materials selected, and the reasons behind those choices. OHK’s facilitators framed the session as a study in strategic fabrication. Participants weren’t simply building; they were learning how to compose material systems that clarify urban complexity without overwhelming the viewer. The session began with a curated walkthrough of the materials table, where over a dozen types of substrates and modeling elements were laid out—ranging from the expected foam boards and museum-grade chipboard to milled plywood, laser-etched acrylic, and matte-finish PLA prints from 3D printers. OHK emphasized that no material is neutral: each carries its own language of communication, legibility, and constraint. Participants were grouped and asked to imagine that they were modeling a civic precinct for public presentation. Their models would need to show not just buildings, but the space between them—streets, parks, topography, shoreline edges, transit lines. As such, material choice had to be strategic.

Chipboard, a favorite for base plates and terrain, was praised for its versatility. At thin layers, it could be laminated to represent topographic elevation changes; when cut thicker, it served well to define district boundaries or arterial corridors. Foam core remained popular for massing exercises because of its ease of modification—participants could quickly shift block heights or carve out courtyards mid-session. For example, an urban corridor through a valley can be built using ascending foam layers, demonstrating how a BRT line could thread through the terrain without excessive slope. More advanced materials included laser-cut basswood and CNC-milled MDF. These were shown to represent infrastructure: bridges, canals, seawalls, and elevated transit systems. OHK demonstrated how a layered MDF base—cut on a CNC router—could not only capture slope and land contour but could also be pre-etched with street grids and parcel boundaries directly from GIS data. In one example shared from a Middle Eastern project, entire transit overlays were engraved into the wood base, while massing volumes were then added on top. This allowed multiple phases of urban development to remain legible even after additional layers were introduced. Laser cutting emerged as the defining tool of the modern civic model. Using vector files exported from Rhino or AutoCAD, participants were shown how to etch not just outlines but gradients, texture, and even regulatory overlays directly onto plywood and acetate. For urban models used in public exhibitions, laser-etched acrylic was often employed to highlight transit routes, waterfront access, or areas under environmental stress—such as flood zones or seismic buffers. When backlit or stacked over light-colored base models, these transparent layers created a spatial conversation between built form and policy constraint.

Participants also experimented with matte PLA 3D-printed inserts—pre-fabricated elements. These included water tanks, radio towers, and solar panel clusters often deployed in low-carbon district proposals. OHK demonstrated the infrastructural logic of a tech campus, adding removable roofs that exposed courtyards and shaded walkways. OHK emphasized that while 3D printing can introduce complexity, its true power lies in producing repetitive components—ideal for large-scale urban housing models or transit-oriented development where patterns matter more than novelty. Cutting and assembly techniques were treated not as afterthoughts but as civic strategies. Using a laser cutter allows for precision and speed, but it also enforces certain design logics—everything must be flattened into profiles, which can change how a topography is conceived. CNC milling allows for depth and vertical nuance, but slows down the process and commits more aggressively to specific terrain interpretations. OHK stressed that each technique carries epistemological weight. “How you choose to cut reflects how you choose to think about the city,” one facilitator noted.

OHK showed an example from a project in East Africa where phasing models had to be broken into quadrants, each of which could be reassembled in a community hall and used to prompt spatial feedback from local residents. In this session, scale was less a constraint than a filter. The models being constructed were not about finish—they were about legibility and argument. One participant observed that using thin acetate to represent sea-level rise created an eerie but effective visual cue: it physically overlaid districts at risk, rather than burying that data in annotation. Another pointed out how laser-etched zoning envelopes could be left exposed to spark conversations about policy flexibility. By the end of the session what emerged, above all, was a realization that the modern urban model is not a singular object—it is a fabrication ecosystem. And in this ecosystem, material is not just matter. It is strategy, clarity, and civic grammar.

The photo above shows the Portland Art Museum, a civic and architectural landmark that served as a central case study in OHK’s physical model-making workshop. Participants explored how a model could be used to represent both the museum’s historic form and its forthcoming transformation through the Rothko Pavilion expansion. Designed by Vinci Hamp Architects, the new glass-walled structure will link the museum’s Main and Mark Buildings while adding gallery space, a rooftop sculpture terrace, and a public community commons at ground level. The workshop examined how such an intervention might be modeled not just as a physical connection, but as a shift in institutional identity, civic openness, and cultural storytelling. By modeling both the existing and the proposed conditions, participants could explore questions of continuity, daylight, circulation, and program—while also reflecting on the legacy of architect Pietro Belluschi, who designed the original museum building in the 1930s. In this exercise, the Portland Art Museum became more than a site—it became a live teaching tool for how cities can represent themselves through careful, crafted forms. Whether analyzing rooflines or gallery adjacencies, a model can helpe translate architecture into dialogue: a platform where spatial change becomes visible, shareable, and subject to collective imagination.

From Idea to Object: Steps in Building a Physical Model—Midway through the afternoon, the OHK team led a focused session titled From Idea to Object, inviting participants to think not just about what they were building, but how. This portion of the workshop demystified the physical act of model-making by walking participants through the core stages of turning a design concept into a constructed, scaled object. Rather than a checklist, these steps were framed as a sequence of decisions, each with spatial, material, and communicative consequences. The first step, defining the purpose of the model, anchored the entire discussion. Was this model being made to test volume? To communicate with a policymaker? To demonstrate construction logic to a builder? The answer would determine everything that followed—from scale, to material, to method of assembly. As OHK explained, a conceptual model for urban massing will be fundamentally different from a detail model of a roof node. “Start with intention,” OHK noted, “or you risk building something that’s beautiful but meaningless.”

Next came choosing the appropriate scale. Participants learned that scale isn’t just a mathematical conversion—it’s a strategic lens that determines what the model can communicate, and to whom. A 1:5000 model is often used at the regional level, helping illustrate relationships between districts, mobility corridors, or ecological boundaries. OHK had used this scale in a national development study for a Levant country, where entire economic zones were positioned in relation to ports, highways, and deserts. Zooming in, a 1:1000 model becomes ideal for urban infrastructure planning—especially useful for understanding how road networks, zoning envelopes, and natural features like flood plains interact. One such model, developed by OHK for an East African coastal city, allowed mayors to evaluate land use scenarios across a stretch of shoreline. A 1:500 model is commonly used for district masterplans. At this level, building footprints, open spaces, and street widths begin to take shape. OHK has employed this scale in Zanzibar to simulate how new urban regeneration can transform Stone Town. A 1:200 model begins to show more formal relationships—block articulation, shared courtyards, and entry sequences. OHK has found this scale powerful when helping developers and municipalities agree on visual impact and buildable area regulations. At 1:100, the model becomes tactile enough for interior volumes and structural systems to be sensed. It’s at this scale that questions like “Can we fit a column-free span here?” or “How does the facade relate to floor slabs?” become legible. At 1:50, the model supports decisions about spatial flow—room-to-room transitions, stairwell arrangements, or entry thresholds. This was the scale OHK chose for a redevelopment of a historic complex in Jerusalem, where local builders needed to visualize corridor widths and ventilation paths before formal drawings had been translated. In several of OHK’s work, these scales have proven especially powerful in contexts where literacy in technical drawings is low, but spatial intuition is high. Together, these varied scales demonstrated not only range, but responsibility: that choosing the wrong scale can obscure meaning, while choosing the right one can unlock understanding.

The fourth step was constructing the primary urban geometry. Participants were encouraged to begin not with isolated buildings, but with the foundational forms of urban structure—gridded blocks, street alignments, open space hierarchies, and topographical shifts. Rather than rushing to represent architectural features, OHK guided participants to shape the underlying logics of city form: Where is the civic heart? How does movement flow? What land is elevated or flood-prone? In many cases, teams began by laying down basic ground planes and massing street corridors, gradually stacking volumes only after the public realm had been defined. As OHK explained, “Don’t rush to buildings—start with systems. A city isn’t façade-deep.” As the models developed, the fifth step emerged: refining with strategic urban detail. But these weren’t architectural accents like window frames or roof pitches—instead, participants were encouraged to add selectively meaningful elements that revealed how the urban fabric functioned. For some teams, that meant carving voids for public plazas or natural drainage basins. Others introduced tree-lined boulevards or pedestrian connections across infrastructure barriers. In OHK’s own planning work, this kind of strategic addition—such as mapping where mid-rise blocks give way to conservation peripheries, or where coastal access must be preserved—often unlocks policy conversations that abstract data never can. “A small setback in a model can reframe an entire zoning debate,” one planner observed during the session.

The sixth and final step was framing the model for civic engagement. How a model is viewed shapes how it is understood. Should it sit flush with the table, inviting touch and informal critique? Should it be lifted on a central platform to guide a more structured discussion? OHK presented examples from previous public exhibitions and stakeholder consultations, showing how model layout—surrounding maps, lighting, layered legends—can either invite inclusive dialogue or enforce top-down interpretation. Participants considered whether to include zoning overlays, phasing layers, or removable land-use sections. Some added edge diagrams showing proposed metro lines or sea level projections. The goal wasn’t to finish a polished object, but to shape a platform for civic conversation. By the end of the session, the table was full of urban fragments: scaled districts with green corridors, flood mitigation cutouts, transit hubs, and layered growth zones. Participants hadn’t just learned to make things—they’d learned to narrate space. And in doing so, they had internalized a principle OHK holds at the center of its practice: model-making is a spatial language, and when used well, it helps cities think out loud.

From GIS Data to Physical Model: OHK Demonstrates 3D Printing with Open-Source Tools for the Island of Zanzibar and a Coastal Downtown

As part of OHK’s ongoing exploration of emerging tools in participatory planning, our team demonstrated how open-source geographic data and accessible 3D printing technologies can be used to create detailed terrain and city models. While traditional-built models remain essential to urban strategy and stakeholder dialogue, this method shows how new fabrication workflows can expand the toolkit—bringing topographic and spatial data into physical form quickly, accurately, and at low cost. Using tools like Terrain2STL, TouchTerrain, and CADMAPPER, the OHK team showcased how anyone—from educators to local planning departments—can extract real-world elevation data or city blocks and convert them into printable 3D models. These tools pull from digital elevation models (DEMs) and OpenStreetMap data, allowing users to download terrain or building models from nearly anywhere in the world.

In the demonstration, a terrain segment from a climate-sensitive coastal region in East Africa was selected. The team generated a printable STL file using Terrain2STL, then refined the model in Tinkercad to shape the footprint and add a base layer. For more detailed urban areas, CADMAPPER was used to include 3D building massing alongside topography. Models were then sliced in PrusaSlicer, printed in PLA filament, and scaled to approximately 1:5000—ideal for tabletop analysis of regional planning. OHK also demonstrated how vertical vs. horizontal print orientations affect model clarity, and how visual features like elevation exaggeration or color changes can support educational and communicative goals. The team emphasized that while these models may lack the narrative richness of a curated civic model, they serve as excellent foundational layers: useful for base mapping, stakeholder orientation, school outreach, and public exhibitions focused on landscape or risk awareness.

More importantly, the demonstration highlighted a core OHK principle: model-making is not about nostalgia—it’s about accessibility and communication. Whether carved from chipboard or printed from an STL, the value lies in helping people grasp complexity through shared, tangible reference points. By integrating open-source workflows into its modeling practice, OHK affirms that the future of planning should commit to hybrid innovation—where tradition meets technology, and where cities become legible not just through policy, but through physical presence. This method complements OHK’s civic-scale models by offering a new entry point: empowering communities, students, and local actors to create and use models of their own, grounded in real data and built for real dialogue.

The use case of Zanzibar was modeled in detail using the open-source terrain printing workflow, demonstrating how large-scale geographic features can be physically fabricated with accessible tools. By applying a scale of 1:8,500, the entire island—measuring approximately 85 km by 30 km—was translated into a 10-meter by 10-meter physical model. Using tools like TouchTerrain and a standard Prusa i3 MK3 printer with a 250 × 210 mm build volume, the model was divided into roughly 1,920 individual tiles for printing. Each tile captured a segment of the island’s topography, with optional vertical exaggeration to enhance subtle elevation changes. While this is an extensive and time-intensive effort, the number of tiles can be significantly reduced by upgrading to a larger-format printer such as the Modix Big-60 (600 × 600 mm) or the Creality CR-M4 (450 × 450 mm). At that scale, the same model could be produced in approximately 400 to 500 tiles, streamlining the fabrication process considerably. This case illustrates how open-source GIS data and scalable 3D printing workflows can bring digitally generated terrains into the physical realm, supporting planning, exhibition, and education through tactile spatial storytelling.

On the right side of the image above is a vignette from a test-of-concept model produced by OHK to explore physical modeling workflows for Stone Town, Zanzibar. As a placeholder for orientation, the small turquoise pool visible in both the model and the aerial photo corresponds to the pool at the Hyatt hotel, which sits directly along the beachfront—offering a real-world reference point within the model’s simplified context.

This photo shows a highly detailed 3D-printed model of a coastal downtown from one of our projects, which we produced using a workflow based on LIDAR data to achieve exceptional resolution in representing buildings, terrain, and urban infrastructure. Unlike broader models such as our Zanzibar example—typically fabricated using data from open-source tools—this model relies on a more advanced geospatial pipeline suited for dense, vertical urban conditions. We began by downloading high-resolution LIDAR data from the USGS LidarExplorer, which captures not only surface elevation but also the contours and forms of individual structures. After converting the data from LAZ to LAS format using LAStools, we imported it into ArcGIS Pro, where we generated a DEM using natural neighbor interpolation. The resulting raster files were refined in QGIS with the DEMto3D plugin, which allowed us to export STL files ready for 3D printing. We divided the model into 40 individual tiles, each measuring roughly 8 × 8 cm, and printed them using a desktop Creality Ender 3 V2 with PLA filament at a 0.25 mm layer height. The final result—seen here—reveals a striking level of detail: the city’s vertical skyline, the texture of its street grid, and even topographic subtleties across the coastline and infrastructure.

This process stands in contrast to the Zanzibar model, which we created to represent the entire island at 1:8,500 scale within a 10 × 10 meter physical footprint. That workflow, based on simplified DEMs, emphasized regional comprehension and was broken into over 1,900 printable tiles using a Prusa i3 MK3. By comparison, this city model demonstrates the power of localized, structure-level modeling—ideal for architectural studies, urban morphology, and emergency preparedness in complex built environments. It required deeper technical tooling, higher resolution data, and a more intensive workflow. Yet both projects are grounded in the same belief: that physical models make the invisible visible. Whether rendering a coastline or a city, we use them to help people grasp complexity, test ideas, and engage in place-based dialogue. At this level of clarity and immersion, a model ceases to be just a representation—it becomes a civic tool for understanding and action.

To scale this city 3D model to a full 10 × 10 meter physical installation using the same method and tile size as the original (8 × 8 cm), we would need to print approximately 15,625 individual tiles. This staggering number arises from the fine resolution of each tile, which covers just 0.0064 square meters. While this level of granularity allows us to capture intricate details—such as the precise form of buildings, the street grid, and even subtle elevation shifts—it also demands an immense amount of time, material, and printer capacity. Printing over fifteen thousand tiles is a tremendous undertaking, requiring not only weeks or months of uninterrupted production but also significant space for post-processing, storage, and eventual assembly. The value, however, lies in the fidelity: a model of this scale and resolution becomes more than a display—it becomes a civic instrument capable of supporting architectural analysis, participatory planning, and educational engagement. To reduce the effort while preserving the overall 10 × 10 meter footprint, we could consider increasing tile size—for example, shifting to 20 × 20 cm tiles would reduce the count to just 2,500. Alternatively, we might limit full-detail printing to select districts, using larger, lower-resolution terrain tiles for peripheral zones. These adjustments can preserve the model’s communicative power while making the process more feasible for large-scale production or exhibition contexts.

In the end, building models is about building understanding. Cities are complex, but possibility becomes real when it’s made visible—cut, assembled, and shared across a table, by many hands.

As cities confront rising complexity—from climate adaptation and migration to equity and infrastructure—model-making offers more than just a design tool. It becomes a civic act. Across OHK’s work in the Middle East, Africa, and beyond, we’ve seen how physical models invite stakeholders to think spatially, collectively, and concretely. They allow abstract ideas to become visible, testable, and debatable. And crucially, they allow decision-making to slow down just enough for reflection, negotiation, and alignment to occur. What Portland’s City of Possibility affirmed is that this practice is not limited to the global South or major megaprojects. Even in highly developed, digitally driven contexts, physical models remain uniquely persuasive. They make complexity graspable and futures imaginable. For OHK, participating in the exhibition and leading a hands-on workshop reaffirmed a core belief: models are not relics of the past—they are rehearsal spaces for what’s next. Whether built from basswood or cardboard, 3D-printed or hand-cut, these small constructions carry large meaning. They are not about perfection. They are about clarity, authorship, and shared direction. In the end, a well-made model doesn’t just describe a city. It invites us to build one—together.

At OHK, we help governments, city agencies, and private developers reimagine urban futures by crafting physical models that clarify complexity, spark dialogue, and build trust. Our expertise lies in translating spatial ideas—whether for a district, waterfront, or innovation zone—into tangible forms that invite critique, iteration, and shared authorship. We don’t just build models; we design processes of engagement. Each base, layer, and sectional cut serves a purpose: to make power legible, to surface trade-offs, to visualize what’s possible—and what must be protected. Our work bridges design, planning, and public conversation. From massing studies that test density thresholds to detailed assemblies that reveal thermal strategies or mobility flows, OHK uses models to ask better questions and co-develop better answers. Whether advising a regional plan in East Africa or facilitating a civic workshop in Portland, we bring a commitment to clarity, plurality, and place. Because in the end, a model isn’t just a tool—it’s a platform. One where diverse voices gather, where futures can be rehearsed, and where cities can be shaped not through abstraction, but through shared vision made visible, cut by cut, and piece by piece. Contact us to learn how we can help you realize the transformation of your city’s most valuable urban assets.