Beneath the visible surface of cities lies an invisible architecture. Subways, tunnels, water systems, data cables, and bunkers form a dense network that sustains urban life while remaining largely unseen. The ground beneath our feet is not a void but a complex territory that holds the infrastructures, memories, and anxieties of our age. In recent years, as land becomes scarce and climate pressures intensify, architects and urbanists have turned their gaze downward, rediscovering the subterranean as both a physical and conceptual frontier. To design underground is to engage with the unseen mechanisms that shape the world above.
The subterranean has long been a site where architecture intersects with politics, technology, and belief. From the catacombs of Rome to the industrial subways of modernity, descent has symbolized both protection and exposure. Twentieth-century urbanism transformed this gesture into a system: metros, shelters, and utilities redefined the city section as an instrument of governance. Beneath the promise of efficiency and progress, the underground absorbed the anxieties of an era of war, surveillance, and collapse. Its evolution reveals not only how societies build, but also how they fear.
Today, the ground has become the new frontier of urban expansion and ecological adaptation. As digital infrastructures, energy systems, and climatic buffers migrate below grade, architecture confronts a space both technical and metaphysical — essential yet marginal, invisible yet decisive. To think in sections rather than in plan is to recognise that contemporary cities no longer exist solely in their skylines but also in their depths. The challenge for architecture is not only to occupy that space, but to render it legible, to turn the unseen into knowledge, and the hidden into a new terrain of design.
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Second Prize Winner: Branch. Image Courtesy of Buildner
Buildner has announced the results of the Howard Waterfall Retreat architecture competition, an international design challenge developed in close collaboration with the Howard Family Trust. The competition invited architects and designers to propose a multi-generational family retreat set within a privately owned, forested landscape in Northwestern Pennsylvania, centered on the dramatic presence of Howard Falls and the surrounding gorge.
Rather than prescribing a singular architectural solution, the brief emphasized a careful dialogue between architecture and nature. Participants were asked to consider how a retreat could balance shared and private living, respond to steep topography and water systems, and integrate sustainably within a sensitive ecological setting. The project also called for an interpretation of family legacy, encouraging designers to acknowledge the history of the site and the original summer cottage while imagining a retreat capable of evolving across generations.
In a world facing ecological exhaustion and spatial saturation, the act of building has come to represent both creation and consumption. For decades, architectural progress was measured by the new: new materials, new technologies, new monuments of ambition. Yet today, the discipline is increasingly shaped by another form of intelligence, one that values what already exists. Architects are learning that doing less can mean designing more, and this shift marks the emergence of what might be called an architecture of restraint: a practice defined by care, maintenance, and the deliberate choice not to build.
The principle recognizes that the most sustainable building is often the one that already stands, and that transformation can occur through preservation, repair, or even absence. Choosing not to build becomes a political and creative act, a response to the material limits of the planet and to the ethical limits of endless growth. That Architecture moves beyond the production of new forms to embrace continuity, extending the life of structures, materials, and memories that already inhabit the world.
Public spaces remain some of the most dynamic sites for unbuilt architectural experimentation, revealing how cities and architects can imagine accessibility, gathering, and civic identity. In this curated Unbuilt edition, submitted by the ArchDaily community, the selected proposals examine parks, pedestrian corridors, cultural landscapes, and open-access urban environments that invite people to meet, move, rest, and participate in collective life. Rather than treating public space as leftover terrain, these projects position it as essential infrastructure—shaping urban health, memory, and social interaction.
As architecture moves beyond human-centered design, new practices are rethinking coexistence as an ethical and ecological framework. From political infrastructures to habitats, these approaches invite us to imagine architecture as a shared living system.
Modern architecture has long been written through an anthropocentric lens, placing the human at its center and rendering other species invisible. Yet this paradigm continues to shift, as architects and researchers redefine the role of design in more-than-human worlds. Studios such as Office for Political Innovation, Studio Ossidiana, and Husos Architects are questioning human-centered narratives and reframing design as a shared practice between species. In this context, architecture is no longer a tool of control but a medium for coexistence, a discipline that mediates between species, environments, and cultures.
The second edition of the Ammodo Architecture Award has recognized 26 recipients for their contributions to socially and ecologically responsible design. Selected from 168 submissions spanning over 60 countries, the laureates represent a wide range of practices, from established offices to emerging collectives and community-led initiatives. Each recipient receives a grant ranging from €10,000 to €150,000 to support the continued development of their projects. Beyond recognition and financial support, the Ammodo Architecture initiative also functions as a knowledge platform, connecting awardees across regions and facilitating the exchange of ideas on key themes identified by the advisory committee.
Shenzhen is China's first Special Economic Zone（SEZ), serving as a window for China's Reform and Opening-up and an emerging immigrant city. It has evolved into an influential, modern, and international metropolis, creating the world-renowned "Shenzhen Speed" and earning the reputation of the "City of Design." Architectural design stands as the most intuitive expression of Shenzhen's spirit of integration and innovation. Over the past decade (2015-2025), the development of urban architecture in Shenzhen has closely integrated with its open and inclusive urban character, ecological advantages of being nestled between mountains and the sea, and the local spirit of blending traditional culture with innovative technology, showcasing Shenzhen's unique charm and robust vitality across multiple dimensions.
Spaces of hospitality are a mirror to how different cultures articulate generosity, care, belonging, and identity. In busy city settings, this is reflected in hotels, service systems, and curated amenities that directly shape the visitor experience. These spaces translate care into measurable forms, where success is correlated with efficiency, luxury, and brand identity.
At a time of ecological collapse and rising food insecurity, architecture is increasingly called upon to engage not only with landscapes but with the systems that sustain and regenerate them. Among these systems, agriculture occupies a paradoxical role, as both a leading contributor to environmental degradation and a potential agent of ecological recovery. Industrial farming has depleted soils, fragmented habitats, and driven climate change through monocultures, fossil-fuel dependency, and territorial standardization. In response, agroecology has emerged as a counter-practice rooted in biodiversity, local knowledge, and the cyclical rhythms of nature. It reframes farming not as extraction, but as regeneration of ecosystems, communities, and the soil itself.
This reframing opens space for architecture to contribute meaningfully. To align with agroecology is not only to support food production, but to engage with the broader cultural, spatial, and ecological conditions that sustain it. It implies designing with seasonal variation, supporting shared use, and building in ways that respect both the land and those who work it. Architecture becomes more than enclosure — it becomes a mediator of cultivation, reciprocity, and coexistence.
Immersive Resilience Garden / Changyeob Lee + Studio ReBuild. Image Courtesy of Studio ReBuild
The concrete canyon of Melbourne's Degraves Street was once a stark service corridor in functional obscurity. Today, the narrow laneway now pulses with life beyond its famous café. Native grasses cascade from carefully positioned planters while small shrubs create cooling microclimates. Challenging traditional ecological design models, community-led approaches to biodiversity invite a reimagining of how architects, planners, and communities collaborate to develop biodiverse urban futures.
Vernacular architecture often utilizes locally sourced materials and construction practices honed over centuries. This approach raises questions about its potential relevance for contemporary design challenges. The prevalence of high-rise developments globally, often relying on sealed envelopes and mechanical climate control, contrasts with historical architectural practices. Traditionally, regional architectures emerged from local communities, fostering distinct cultural identities and integrating passive systems for ventilation, cooling, and heating, often utilizing natural elements. The Hanok, traditional Korean houses, serve as a case study. Beyond their current role in tourism, they are also an example of how vernacular knowledge can provide passive climate-response strategies that align with the current principles of creating environmentally friendly buildings.
NDSM Lusthof / Studio Ossidiana. Image Courtesy of Studio Ossidiana, Riccardo de Vecchi
As climate instability reshapes design priorities, architecture is increasingly drawn into ecological debates not as a spectator but as a participant. Among the concepts gaining traction is rewilding, a practice rooted in the restoration of self-sustaining ecosystems through the reintroduction of biodiversity, the removal of barriers, and the rebalancing of human presence in the landscape. Though often associated with conservation biology, rewilding also opens up new spatial and architectural imaginaries — ones that challenge conventional notions of permanence, authorship, and use.
