HORTUS, by Herzog & de Meuron, is a rammed earth timber building under construction in Basel, Switzerland. Image courtesy Herzog & de MeuronIn the spring of last year, I travelled to research the emerging field of bio-regional design, experiencing first-hand how exceptional architectural and material practices are forging a path forward to a healthier, lower-carbon future for our built environment. I am the latest recipient of DIALOGs Iris Prize, an internal research and travel grant for practitioners, awarded annually to explore innovative ideas that meaningfully improve the wellbeing of communities and the environment we share. What follows is a dispatch from my research trip.The bio-regional design framework is straightforward: it focuses on locality, biomaterials and new construction processes to achieve exceptional results. The challenge lies in implementationbreaking free from the status quo of a global network reliant on high-carbon, unsustainable construction materials. In a bio-regional approach, the process of construction becomes as important as the design itself, with novel techniques and, often, new materials being created.In Basel, Switzerland, Atelier Tsuyoshi Tane has designed the Vitra campuss most sustainable building to date: a small garden house made from thatch and timber, using materials that are grown instead of those extracted from below ground. Meanwhile, in Basel, Herzog & de Meuron are constructing HORTUS, a five-storey building designed to be net energy-positive within 31 years. It features a rammed earth structural floor system, developed together with the client Senn AG and ZPF Ingenieure, and a reduced material palette of clay, wood, and cellulose. It is, without question, the most ambitious example of building at scale using natural materials that Ive seen: the approach is imaginative and technically rigorous, resulting in a stunning building.BC Architects, Materials, and Studies: building with earth and inspiring others in Brussels, Belgium. Photo by BC ArchitectsBC Architects, Materials, and Studies in Brussels operate as a tripartite practice, specializing in earth construction, using surplus excavated soil from building sites. They began as an architecture studio but discovered that Brussels urban geology is ideal for creating rammed earth and other earth-based building products. This led the architects to establish a materials company, BC Materials, which manufactures products like earth blocks (replacements for traditional concrete masonry blocks), fired bricks, mixes for unstabilized rammed earth (made without cement binders and fully reusable), and earth plasters and paints for interior finishes. They also founded BC Studies, a branch dedicated to education and teaching others.On a hot summer day, I joined one of BC Architects Earth Discovery Day workshops at their shared workspace with BC Materials. Alongside a small group of architects, builders, and students, I participated in hands-on exercises to experiment with different earth product mixes. I left with clay under my fingernails, sand in my shoes, and excitement for the potential of earth-based construction. Reused materials sorted and stockpiled by Rotor, a practice based on reuse and the circular economy in Brussels, Belgium. Photo by Victoria Van KanRotor, another Brussels-based practice, focuses on salvaging construction materials from the built environment. They operate both as a supply outlet for dismantled and reclaimed building components, and as consultants helping other design practices integrate circular construction strategies.Their large warehouse in northern Brussels showcases salvaged materials, which are often sold at lower costs than new products, to those who appreciate the patina and texture of second-hand materials. Rotor has also conducted several EU studies on circular construction, and is involved in ambitious projects like the adaptive reuse and retrofit of an 18-storey office tower in collaboration with Snhetta. Their goal: to allocate 3% of the buildings overall weight and cost to repurposed materials. When I visited their studio, the team was busy preparing an exhibition to highlight the work they and others across Europe are doing to advance circular construction practices.What stood out most during the trip wasnt the novelty or innovation of these construction techniquesit was the openness with which everyone shared their learnings, taught others, and inspired action. There was an urgent sense of responsibility to move toward a more sustainable future. Now that Im back in Canada, the challenge is figuring out how to create our own regional approaches to low-carbon building.As appeared in theFebruary 2025issue of Canadian Architect magazine The post RAIC Journal: We are going to do this togetherReflections on a bio-regional design research trip appeared first on Canadian Architect.