besley & spresser transform asbestos into carbon-negative materials for lisbon triennale

Besley & Spresser Reconsider Asbestos and Its Lasting Impact

At the Lisbon Triennale 2025, Besley & Spresser introduce a material provocation presented in the form of an architectural installation, anchored by a striking question posed by Peter Besley:
What if one of the construction industry’s most hazardous materials could become one of its most promising?

Working alongside co-founder Jessica Spresser, the studio reconsiders asbestos as a mineral whose future could depart significantly from its historically harmful trajectory. Their project, REDUX, installed within the Palácio Sinel de Cordes, features carbon-negative materials produced from asbestos waste. These materials were developed in collaboration with Rotterdam-based material researchers Asbeter and ceramic artist Benedetta Pompilli.

The installation demonstrates a certified EU process that transforms asbestos through recrystallization, turning it into stable silicate minerals that are safe to handle, structurally viable, and visually compelling. As the architects explain, the aim is to shift asbestos from a cultural taboo to a material of renewed possibility showing that substances marked by deeply troubled histories can be reimagined into something constructive, safe, and unexpectedly beautiful

images by Rui Cardoso, unless stated otherwise

turning a toxic legacy into carbon-negative material

Asbestos is an ancient mineral that became deeply embedded in urban environments through decades of industrial optimism and regulatory oversight. Although naturally occurring and not inherently toxic, the ways it was mined, processed, and installed introduced a severe and enduring public-health risk. Its legacy continues to cause hundreds of thousands of deaths each year while leaving millions of tons of contaminated waste in landfills around the world.

Besley & Spresser’s installation situates itself directly within this complex history. The architects highlight a central contradiction within industrial material culture: the tension between convenience and long-term harm. As Besley explains, asbestos exemplifies this paradox its practicality contrasted sharply with the damage it ultimately inflicted. Through REDUX, the studio seeks to contribute to a broader reconsideration of how cities use, value, and renew their material resources.

Besley & Spresser present a material provocation disguised as an architectural installation

From Hazardous Fibres to Carbon-Negative Architecture

The scientific process underlying REDUX is both rigorous and unexpectedly generative. As the architects explain, the renewal method involves heating asbestos waste to high temperatures within a controlled environment. This treatment eliminates its hazardous fibrous structure and causes the material to recrystallize into stable silicate minerals. These resulting minerals can serve as partial cement replacements or be incorporated as additives in other construction materials. Notably, the process also absorbs carbon dioxide, classifying it as carbon-negative.

Given that cement production accounts for approximately 8% of global carbon emissions, the ability of renewed asbestos minerals to replace up to 25% of traditional cement content positions this technology as a promising environmental intervention.

The architects were also struck by the material’s aesthetic potential, particularly the ceramic glazes developed by Pompilli. They note that the renewed mineral produces glazes with vivid, sometimes unpredictable color variations, influenced by the composition of the original asbestos source. This visual dimension highlights the surprising expressive range of a material once defined solely by danger.
the studio reframes asbestos as a mineral whose future might diverge radically from its past

REDUX Explores Repair as Both a Technical and Poetic Act

Constructed from these renewed materials, the installation at Sinel de Cordes functions simultaneously as a spatial essay and a technical demonstration. It suggests that cities can recover by transforming their own discarded substances and that meaningful innovation can arise from materials once associated primarily with harm. The architects emphasize that design holds the capacity to convert legacies of damage into opportunities for restoration. Asbestos buried in peripheral landfills continues to risk environmental contamination, while aging asbestos-containing buildings pose ongoing health challenges worldwide. Safe, scalable transformation of asbestos could reclaim vast areas of urban land, enabling their conversion into parklands, ecological corridors, or sites for sustainable housing.

Within the installation, visitors are encouraged to touch the renewed materials an intentionally provocative act given the widespread stigma surrounding asbestos. By allowing direct physical engagement, REDUX fosters a deeper, experiential understanding of material transformation. As the architects explain, the aim is to shift asbestos from a symbol of taboo to one of possibility.

REDUX showcases carbon-negative materials derived from asbestos waste

origins of the project

The architects explain that the project’s origins trace back not to a laboratory but to a university classroom. In a 2023 Master of Architecture studio at the University of Sydney, students examined local asbestos dumping sites as part of their research. One team—comprising Thomas Li, Kleopatra Ananda, and Jasmine Sharp—mapped the material’s urban footprint and ultimately directed the architects toward Asbeter in the Netherlands.

Asbeter, pioneers in asbestos renewal technologies, developed a mineral recrystallization process capable of neutralizing asbestos fibers safely and effectively. According to the architects, this discovery revealed a much broader global potential: transforming a material historically defined by danger and stigma into a carbon-negative resource with a wide range of architectural applications, from concrete and render to ceramic glazes.

the architects point to the paradox of industrial material culture

asbestos is an ancient mineral, woven into the urban fabric | image courtesy of Besley & Spresser

recrystallizing asbestos into stable silicates | image courtesy of Besley & Spresser

the scientific process is uncompromising and surprisingly generative | image courtesy of Besley & Spresser

✦ ArchUp Editorial Insight

Besley Spresser’s contribution to the Lisbon Architecture Triennale 2025 offers a provocative inversion: turning a historically toxic material—asbestos—into a vehicle for carbon negativity. The installation reimagines waste as architecture, constructing translucent sheets from synthetic, inert “asbestos-like” fibers that paradoxically clean the air. The project sits at the intersection of speculative design and environmental activism, but the article fails to interrogate the material claims with technical rigor. No mention is made of lifecycle analysis, structural performance, or regulatory acceptance, which leaves the core proposition floating in conceptual space. Is this art? Architecture? A manifesto? The ambiguity might be intentional, yet without deeper architectural grounding, the work risks becoming novelty rather than praxis. Still, the project earns credit for confronting taboos and re-framing climate discourse through design fiction. A decade from now, such speculative provocations may catalyze new policies or material revolutions—but only if grounded in verifiable pathways.