Normalising unconventional materials through cultural knowledge exchange between Oaxaca and Perth: Exploring Typha domingensis as an alternative binding agent for earth construction

This paper presents an exploratory study of natural building materials framed around an architect-in-residence program at the University of Western Australia, in which Dr Joao Boto Caeiro, an Oaxaca-based architect and academic experienced in community-driven earth building, engaged with Perth-based academics currently undertaking material investigations on the use of Typha domingensis in construction materials.<br/><br/>While earthen architecture remains normalized in many parts of Mexico — where traditional and contemporary practitioners regularly design with rammed earth, adobe and cob — it faces cultural stigma and regulatory hurdles in Australia, limiting its uptake despite significant benefits for sustainable construction.<br/>Typha domingensis is a fast-growing wetland plant present in both Western Australia and Oaxaca, Mexico. In both locations it is a significant component of the local ecosystems and has been used traditionally by Indigenous communities for various purposes. Its prolific growth and dominating behaviour frequently lead to a requirement for management which makes it a promising biomaterial resource. <br/><br/>The central questions explored in this paper are: <br/><br/>1. What are the benefits of the use of Typha as a binding agent in earth construction in Perth and Oaxaca?<br/>2. What social, regulatory, and perceptual barriers inhibit acceptance of earthen materials in Perth in comparison to Oaxaca? <br/>3. How might targeted cultural exchanges, underpinned by technical evidence, shift professional and public attitudes toward earth construction?<br/><br/>During the residency, participatory workshops provided hands-on experimentation with materials such as earth, Typha, straw, timber sawdust, and lime composites, enabling direct comparison of material workability, structural integrity and aesthetic qualities. Informal design critiques fostered cross-cultural dialogue, unpacking assumptions around durability, regulatory compliance and market demand. A literature review synthesizes global LCA (Life Cycle Assessment) studies on the impacts of earthen construction highlighting the contextual relevance to Perth, Western Australia, while Typha is compared to LCA studies of similar fibrous materials used in earth construction to understand the potentials for substitution. <br/><br/>This research contributes to the field of sustainable architecture by exploring how cultural knowledge exchange can normalize the use of unconventional materials, with the goal of catalysing practice-led sustainability transitions. By combining empirical data, technical evaluation and collaborative pedagogy, the work establishes a starting point for further exploration. The paper argues for the value of bridging cultural divides in material practice to not only enrich design innovation but also advance decarbonisation pathways in the built environment.<br/>