Still from the documentary To Build Law, 2024 © CCA**

Concrete, steel, wood, glass. Every year, millions of tons of construction materials are discarded, piled up in landfills, and silenced beneath the weight of the next building. Entire structures disappear to make way for others, restarting a voracious cycle of resource extraction, material production, and replacement. Along with the debris that accumulates, something deeper is also lost: time, human labor, stories, and the collective memory embedded in matter. At a time when climate goals demand reducing emissions and extending the lifespan of what already exists, demolition is increasingly recognized as a form of urban amnesia, one that erases not only cultural continuity but also the embodied energy of buildings. And even though it is often said that the most sustainable building is the one that already exists, that principle rarely survives when other interests come into play.

In response, initiatives such as HouseEurope!, winner of this year’s OBEL Award, propose a paradigm shift: reuse should become the rule, not the exception. Their starting point is clear. As Campaign Manager Alina Kolar states, “Europe is on track to demolish roughly 2 billion m² of buildings by 2050. Just to replace them with new buildings. The current system is designed to demolish and build anew.” The problem is not only technical but structural: financial systems, legislation, and tax incentives still favor new construction, while existing buildings are treated as obstacles to progress.

Still from the documentary To Build Law, 2024 © CCAStill from the documentary To Build Law, 2024 © CCA

Too often, the decision to demolish is guided more by economic criteria than by an integrated vision of urban or social development. The potential for financial gain tends to prevail over the opportunity to reuse what already exists, leading to the replacement of structures that once served community or residential purposes with more profitable developments. While economically justifiable, this dynamic can produce significant transformations in the urban landscape and the social fabric of neighborhoods.

The pursuit of “modernity” and “revitalization” adds another layer to the issue. Even structurally sound buildings are frequently deemed obsolete, sacrificed in favor of aesthetics and the market appeal of novelty. In high-value urban areas, this logic is reinforced by the imbalance between land value and construction value, as plots become more profitable when cleared for denser or taller developments. Financial mechanisms and tax incentives also play a decisive role, often rewarding demolition and new construction instead of preservation. Combined with speculative real estate cycles, these factors create a self-sustaining system that privileges short-term gains over sustainability and cultural continuity.

Embodied Energy and the Memory of Matter

Each demolition wastes a reservoir of accumulated energy and releases even more carbon to rebuild what already existed. Every building is a repository of energy. That means that besides the kilowatt-hours needed to produce its materials, there is also all the human and natural effort that shaped them.

Courtesy of BOGDAN & VAN BROECK. ImageThe Cosmopolitan Building / BOGDAN & VAN BROECK

“Every building holds what we call embodied or grey energy: the sum of all resources, human effort, and carbon emissions that went into extracting materials, producing components, transporting them, and assembling them on site. When we demolish, we don’t just destroy materials; we erase that stored energy and release new emissions to replace what is already here,” explains Kolar.

But not everything we lose can be measured in tons or megajoules. Demolition also erases what cannot fit into a spreadsheet: relationships, crafts, and belonging. When a building disappears, the invisible networks that sustained it collapse as well. Each structure preserves layers of human presence—traces of use, affection, and labor—forming a repository of time. Worn surfaces, layers of paint, and improvised repairs record the passage of generations and the ways of inhabiting a place. Renovation, by contrast, preserves not only materials but also social and economic ecosystems, jobs, local commerce, and neighborhood memories. What is often dismissed as “subjective” is, in fact, a form of social and cultural value that should carry weight in urban decisions. “By turning care into data—without stripping it of meaning—we can make it count,” Kolar adds.

© Margherita Spiluttini. ImageTate Modern_Herzog & de Meuron_©Architekturzentrum Wien, Sammlung©Stijn Brakkee. ImageDe Flat Kleiburg / NL Architects_XVW architectuur

The understanding of buildings as repositories of collective memory spans various disciplines, from urban anthropology to heritage studies. Authors like Kevin Lynch and Aldo Rossi demonstrated that the built form carries meanings beyond the material: it organizes memory, shapes identity, and gives form to the experience of time in cities. For Lynch, the urban image is both mental and emotional, a map of memories that helps citizens recognize themselves in their surroundings. Rossi understood the city as a collective artifact, where buildings act as “urban facts” that embody continuity and crystallize the relationship between past and present. Henri Lefebvre expanded this view by defining space as a social product, shaped by practices and conflicts rather than as a passive backdrop. Jane Jacobs, in turn, argued that urban vitality stems precisely from continuity, the intertwining of times, uses, and stories that coexist in one place. When these structures are demolished, we lose more than physical objects; we lose part of the symbolic grammar through which communities understand their own trajectory.

Reuse also activates another kind of knowledge: craftsmanship. Working with existing structures requires both technical skill and sensitivity, and this is reflected in the satisfaction of those who practice it. “Over 80 percent of craftspeople say they prefer working with existing buildings because their skills are more visible and can be more meaningfully applied,” Kolar notes. In renovation projects, the craftsman’s gesture reappears as a visible part of the construction narrative, restoring a sense of authorship often lost in standardized building processes.

Defining what makes a building reusable is a key step in this paradigm shift. Technically, it occurs when the primary structure and spatial systems can be preserved, reinforced, or adapted without complete demolition. “Politically, we need a bright line—in our proposal, at least 20 percent of the building must be retained to qualify as renovation.” Reuse, therefore, involves maintaining structural integrity, ensuring adaptability, and preserving material continuity. This process begins with thorough technical assessments and precise documentation of existing conditions. Techniques such as 3D scanning and digital modeling help record structural and material realities, turning uncertainty into knowledge and allowing architects to design with precision rather than assumption. To support this approach, methodologies and tools such as Life Cycle Assessment (LCA), Building Information Modeling (BIM), and material passports are essential, allowing the quantification of embodied energy, integrity, and lifespan, and transforming reuse potential from an intangible idea into measurable data.

© Philippe Ruault. ImageTransformation of 530 dwellings / Lacaton & Vassal + Frédéric Druot + Christophe Hutin architecture© Philippe Ruault. ImageTransformation of 530 dwellings / Lacaton & Vassal + Frédéric Druot + Christophe Hutin architecture

This perspective recognizes that rehabilitation is neither nostalgic nor merely aesthetic; it is a technical and political decision. It requires clear criteria, incentives, and institutional commitment for renovation to truly become the first option considered. As Kolar puts it, “Design seeks expression and meaning through transformation; policy seeks regulation and measurement. Connecting both is key to making the sustainable option the easier one.” In other words, creativity and technical rigor must come together to make care an operational principle.

Policy, Education, and the Future of Transformation

On the political front, change is already taking shape. Through the European Citizens’ Initiative, HouseEurope! is advocating to rebalance the conditions between demolition and reuse, addressing issues such as VAT reform, embodied-carbon accounting, and renovation-first criteria in EU funding. The goal is straightforward: to make the sustainable option the easiest, fastest, and most affordable path forward. The objective is to reverse the system’s logic, making the sustainable choice the most accessible and efficient one. This goes beyond laws or taxes; it is also a cultural and educational transition. “Make reuse core, not elective,” Kolar emphasizes. Reuse should not be a specialization but the foundation of architectural and engineering education. “Architecture is not only about creating new buildings, but about working with what already exists—with structures, materials, and communities already in place.”

Courtesy of Amunt Architekten Martenson und Nagel Theissen. ImageSchreber / Amunt Architekten Martenson und Nagel Theissen© Filip Dujardin. ImageSchreber / Amunt Architekten Martenson und Nagel Theissen

Learning to read and transform what stands is also learning to build differently with time, empathy, and awareness. Preservation is not resistance to the new but a reconciliation of time and matter, aligning ecology, culture, and design intelligence. Recognizing what already exists does not hinder progress; it cultivates it responsibly. Within their walls and structures, buildings hold what may be the most valuable lesson for the future of architecture: progress can, and should, be an act of care.

HouseEurope! continues to work toward making this idea a public policy, inviting architects, citizens, and governments to join the Power to Renovation movement, which seeks to make reuse a requirement before demolition. Learn more and sign the petition athouseeurope.eu.

**Cite: **Eduardo Souza. “Material Memory: What We Lose When We Demolish Buildings” 31 Oct 2025. ArchDaily. Accessed . <https://www.archdaily.com/1035402/material-memory-what-we-lose-when-we-demolish-buildings> ISSN 0719-8884