This study explores the potential of Karshif, a salt-rich earth material from Egypt’s Western Desert, as a sustainable alternative to energy-intensive bricks as building materials. Traditional Egyptian architecture demonstrates remarkable integration of local materials and climatic considerations, but modern construction practices often overlook these principles, favoring fired clay bricks with higher environmental impacts. Building on the concept of “form-follows climate,” the research proposes a redesigned Karshif brick incorporating advanced geometrical features to enhance thermal performance, self-shading, and natural ventilation. Utilizing 3D printing for mold fabrication, the study introduces an innovative production process that allows for precise, resource-efficient brick design while integrating vernacular material practices. The methodology combines material characterization, laboratory tests, and computational fluid dynamics (CFD) simulations. Karshif’s hygrothermal performance was considered, revealing its capacity for effective moisture regulation and reduced thermal conductivity due to its unique composition of halite, clay, and calcium sulphate. A modular brick geometry, with ventilation channels and optimized external surface features, was designed to reduce heat gain and promote passive cooling. CFD analysis demonstrated the brick’s significant damping effect on wind velocity and its ability to stabilize indoor temperatures and relative humidity under typical Egyptian summer conditions. Compared to conventional fired bricks, Karshif blocks improved thermal comfort while reducing energy demands. The findings highlight the viability of Karshif as a low-carbon, culturally resonant building material capable of bridging traditional wisdom and modern sustainability goals. Challenges remain in scaling production, ensuring long-term durability, and meeting regulatory standards, but the research paves the way for integrating locally sourced, climate-responsive materials into contemporary construction. Future studies will refine Karshif’s design, evaluate real-life applications, and address potential enhancements to optimize its performance and adaptability. This work underscores the broader importance of rediscovering indigenous materials to advance sustainable architectural practices in the global south.