How does the construction sector shape the future of cities? What challenges does it face? At the crossroads of demographic, social, energy, and climate pressures, the construction sector is changing fast. Professionals, institutions, and citizens are working together to build environments that improve health and well-being, encourages durable and place-responsive solutions, cut carbon emissions, withstand climate risks, and provide affordable, high-quality housing.
Collective housing remains one of the most active areas for unbuilt architectural exploration, revealing how architects are rethinking domestic life, density, and shared living across different cultural and environmental contexts. In this curated Unbuilt edition, submitted by the ArchDaily community, the selected proposals investigate new forms of dwelling that span mobile units, vertical developments, adaptive reuse, and landscape-driven residential clusters. Rather than treating housing as a purely functional container, these projects position it as a social and spatial framework that shapes everyday life, community ties, and long-term urban resilience.
Across varied geographies, from Tirana and Athens to Monterrey, Chaloos, Roatán, Bhola, and the DRC, these proposals explore multiple approaches to collective living: transforming industrial shells into residential structures, extending existing masterplans through landscape integration, reimagining verticality in dense urban centers, and developing modular prototypes that can adapt to changing climates or patterns of mobility. Some projects prioritize ecological strategies and local materials, while others test new models for accessibility, community well-being, or incremental urban growth. Together, they reflect a broad spectrum of architectural responses to contemporary housing pressures.
Mishing traditional bamboo house, Majuli . Photo by Rumi Borah. License Creative Commons Attribution-Share Alike 4.0 International
Across India's varied geographies, from coastal backwaters to desert fortress cities, architecture evolved with a deep, instinctive connection to climate. These were not isolated craft traditions but complete ecological systems in which material cycles, thermal comfort, and community knowledge were interdependent. As COP30 turns global attention toward the links between heritage and climate resilience, India's vernacular practices appear less as historical artifacts and more as climate technologies refined over centuries.
On November 21, 2025, the closing day of the 30th edition of the Conference of the Parties (COP) took place, the yearly gathering of United Nations member states to negotiate international climate agreements and assess global progress toward emissions reduction. This year, the event was held in Belém, Brazil, a port city of fewer than 1.5 million people, widely known as a gateway to Brazil's lower Amazon region. First convened in 1992, UN Climate Change Conferences (or COPs) are an international multilateral decision-making forum on climate change involving 198 "Parties" (197 countries, nearly all of them, depending on definitions of country, and the European Union). Their purpose is to assess global efforts toward the central Paris Agreement aim of limiting global warming to as close as possible to 1.5 °C above pre-industrial levels. The event brings together leaders and negotiators from member states, business figures, young people, climate scientists, Indigenous Peoples, and civil society around issues considered essential to that climate goal. This year, COP30 was marked by strong criticism of its ties to the fossil fuel industry, descriptions of agreements as fragile and insubstantial, and the struggle to move climate finance "from pledge to lifeline."
Cities bring together the best and worst of the human condition. They concentrate opportunities for work, social networks, and cultural production, but they also expose deep social inequalities. Among the many forms of urban exclusion are limited access to transportation, housing, leisure, or safety issues. One form that is rarely discussed is thermal inequality. In lower-income neighborhoods, where there are fewer trees, parks, and permeable surfaces, heat accumulates and thermal discomfort dominates, resulting in higher energy consumption and health risks. As concern about the climate crisis grows, this discussion becomes more urgent: extreme heat is no longer just a climatic phenomenon but also a spatial expression of inequality.
From building codes to mobility restrictions and new diplomatic roles within city governments, climate policy is increasingly being shaped at the local level through a widening range of legislative and institutional tools. Cities as varied as Sydney, Boston, New York, Paris, Miami, and dozens across Latin America are adopting targeted strategies that reflect their distinct environmental pressures and governance structures. These initiatives range from all-electric and net-zero construction requirements, to traffic-control measures designed to curb the social costs of private vehicle use, to emerging forms of urban diplomacy that coordinate responses to rising temperatures and biodiversity loss. Together, these approaches illustrate how territorial management is evolving in response to the accelerating climate crisis, and how local governments are experimenting with regulation and collaboration to confront challenges that are at once global and deeply place-specific.
Biodiversity, defined by the World Wide Fund for Nature (WWF) as the different kinds of life found in an area, is in a state of crisis all across the world, with declines in the numbers of organisms and many species declared as at risk of extinction. All types are affected, from plants and fungi to large mammals, and there is a clear link to human activity being the cause. Although farming methods and climate change due to greenhouse gases play a major role, cities and buildings can play a small but important role in countering this decline.
Edinburgh Castle in Scotland’s Capital. Image by 瑞丽江的河水, via Wikimedia Commons (CC BY-SA 4.0)
Edinburgh, Scotland's capital, has long been recognized for its rich cultural history and intricate urban fabric. The city thrives within its museums, tenement housing, and shops nestled in Georgian buildings. In 2022, Time Out ranked Edinburgh as the world's best city, citing its efficiency across community building and urban systems such as public transport. However, as climate change makes its effects progressively visible at an urban level, the city inevitably runs into a pressing dilemma: how to sustain this quality of life in increasingly difficult conditions.
The journey toward this balance unfolds through several interconnected strategies, such as retrofitting, adaptive reuse, circular design, and community collaboration, each contributing to Edinburgh's evolving vision of a sustainable urban future.
With just a few days left before the six-and-a-half-month 19th Venice Architecture Biennale comes to an end, it is possible to look back on some of the most notable contributions within its thematic framework. Marked by the largest call for participants to date, the Biennale's diversity of topics and the range of installations on display go beyond easy recapitulation. As part of that reflection, several initiatives can be highlighted as illustrative of the principles reflected in the curatorial theme, "Intelligens. Natural. Artificial. Collective." The concepts interwoven in Carlo Ratti's title form a call to address the urgent need for substantial solutions amid the accelerating climate crisis, positioning the Biennale as a platform for diverse design proposals and experiments organized around three forms of intelligence: natural, artificial, and collective. Beyond the national pavilions and numerous collateral events held throughout Venice over the past six months, among the more than 700 participants are projects that, through practice, embody four shared intentions: opening conversations about the future, proposing systemic responses to local realities, placing technology at the center of design innovation, and pursuing material research rooted in local sensitivity.
Vernacular architecture is often referred to as harboring lessons for creating low-energy buildings and the fight against climate change. Yet, as weather patterns are changing, there are cases where traditional building techniques are themselves becoming at risk. As well as changes in temperature, different regions have faced becoming wetter or drier, experiencing increased risk of droughts, flooding, storms, and changes to local flora. The painted houses of Tiébélé in Burkina Faso, recognized as a UNESCO World Heritage Site, are one example.
In heritage districts from Prague to Paris, a countdown has begun. Years until countless architectural treasures become, quite literally, worthless. Not through the slow erosion of time or the erratic shifts of cultural taste, but through the inevitable mathematics of atmospheric chemistry. In UrbanDecarbonisation: Destranding Cities for a Post-fossil Future, Paolo Cresci, Francesca Galeazzi, and Aurel von Richthofen introduce the concept of "carbon stranding", a scenario in which buildings become financially non-viable due to tightening carbon regulations. This threatens to render entire heritage districts financially extinct before they reach their centennials.
Harvard University Graduate School of Design (GSD) has announced Maura Marinelli, co-founder of franzosomarinelli, as the winner of the 2025 Wheelwright Prize. The annual $100,000 grant supports emerging architects in pursuing investigative research that addresses contemporary architectural challenges with a global perspective. Marinelli's winning proposal, "Topographies of Resistance: Architecture and the Survival of Cultures," explores how architecture can sustain and revitalizerural, mountainous regions that confront climate change, infrastructure limitations, and cultural erosion. His research aims to develop design strategies that promote autonomy, sustainability, and local identity by comparing contexts in the Alps, Andes, and Himalayas. Through fieldwork and analysis, the project seeks to propose architectural approaches that empower communities and challenge urban-centric perspectives.
Germany's contribution to the 19th Venice Architecture Biennale 2025 exposes visitors physically and psychologically to the future urban climate: a STRESSTEST that makes the need for immediate action palpable. The exhibition takes a clear stance: climate change is an unstoppable reality, and the measures taken so far are inadequate. It presents a scenario in which climate change manifests globally through rising temperatures, extreme weather, and sea level rise, with its effects directly felt at a local level: urban spaces suffering from heat stress. Curators Nicola Borgmann, Elisabeth Endres, Gabriele G. Kiefer, and Daniele Santucci have designed an exhibition to highlight the impacts of global warming on urban life in an urgent call to action, emphasizing that this reality threatens urban social life, productivity, and the health and survival of citizens.
The Deutsches Architekturmuseum (DAM) in Frankfurt has launched its new exhibitionArchitecture and Energy: Building in the Age of Climate Change on June 14, which will be open to visitors until October 5, 2025. Developed in collaboration with engineer and sustainability advocate Werner Sobek, the exhibition explores the intersections of architecture, energy, and climate, focusing on the environmental impact of the built environment and the role of architecture in mitigating climate change. By framing architecture as both a challenge and an opportunity in the context of the climate crisis, the exhibition seeks to contribute to a broader shift in thinking, one that positions design as a vital component of a sustainable future.
Waru Waru agricultural field. Image via World Monuments Fund
Offering a path toward resilience and food security in the alluvial plains of Lake Titicaca, the Waru Waru agricultural fields are spread across the Peruvian highlands and constitute an ancient agricultural system. Connecting an ancestral legacy with modern concerns about water and food security, climate resilience, and sustainable land management, these agricultural systems open the debate about efficient water management and the importance of agricultural biodiversity. At the same time, they are part of the sense of identity and pride of the local Aymara community, consolidating cultural knowledge that is passed down and preserved across generations.
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.
Extreme heat is one of climate change's most urgent and rapidly growing consequences, especially in cities. Urban areas are particularly vulnerable because they trap heat in building materials and urban streets, creating dangerous conditions for residents. As temperatures continue to rise and heat waves lengthen, cities are grappling with how to remain livable in the face of this intensifying threat.
In recent years, architecture has increasingly embraced adaptability, flexibility, and responsiveness as core design principles. This evolution reflects a shift from traditional notions of static, permanent structures to dynamic environments that can adjust to changing needs and conditions. Central to this transformation is the concept of "soft architecture", which leverages pliable materials and innovative systems to create spaces that are functional, sustainable, and user-centric. Soft architecture takes shape through membranes that breathe, façades that move, structures that inflate or fold, and surfaces that bend rather than break. It involves designing for transformation — not only in how a building performs environmentally, but also in how it can accommodate shifting functions, user interactions, or temporary occupations. This approach to building challenges traditional notions of durability and control, proposing instead a more responsive and open-ended architecture. It reflects a growing awareness that buildings, like the societies they serve, must be able to evolve.