This research explores algae-derived materials for carbon-storing interior surfaces through a material-driven design methodology. Waste Cladophora algae, together with oyster shell, alginate, and hemp fibers, are transformed into a biodegradable, low-carbon material. Digital fabrication techniques, including 3D printing and parametrically designed systems with mold casting, are used to shape these composites into functional interior components. Mechanical testing, specifically tensile strength analysis following ASTM D3039 standards, evaluates the material’s performance and its potential as an alternative to conventional building components. Digital workflows enable efficient form generation, reduce waste, and allow computational design to respond to material behavior. Locally sourced and inherently biodegradable, the algae-based composite supports a circular system, returning to the environment at the end of its life. By aligning digital fabrication with ecological goals, this research contributes to the development of sustainable building materials, positioning algae as a viable solution within the broader discourse on carbon-neutral construction and regenerative design.