Natural building materials are a critical future of a decarbonized built environment. Involving raw materials such as clay-rich soils and vegetable fibers in building processes employ a range of techniques, and hence, a range of environmental and visual features, from rammed earth, to cob and light straw clay. However, despite their advantages, natural materials are not represented in mainstream construction, perceived mistakenly as poor in their performance, low-tech, and are missing representation in training for building professionals. Earthen Builder: Life-Cycle Assessment presents a digital tool for designing architecture with natural materials and visualizing their associated embodied carbon (carbon footprint measurement covering the production, transportation, and construction of building materials). It links, for the first time, computational play and critical data with traditional recipes of designing with natural materials. The project’s primary goal was to identify how game technology can advance the knowledge base of an overlooked, historic, and sustainable practice. The result showcases a digital tool for sustainable engagement that utilizes a geological database of locally available soil-based repositories to decarbonize building materials. As an exploratory design tool, it was tested for its mechanics, graphical user interface, and perception shifts among designers and researchers. The final outcome seeks to establish a digital foundation for a more comprehensive earthen materials knowledge tool and life-cycle assessment. Click here to access paper publication.