This project involves the design of a 3-mat sōan teahouse situated in a valley in Kamakura. As the site is located within a designated red zone, reinforced concrete construction was required for safety. The design explores how the spatial qualities of the sōan teahouse can be expressed through contemporary materials. High-pressure washing was applied to the concrete surfaces to evoke the texture of traditional earthen walls, while lauan plywood formwork was used to cast the lower wall panels. In the shitaji-mado, rebar replaces the conventional bamboo lattice, and agathis, a tropical hardwood, substitutes for the customary Yoshino cedar in the millwork. While referencing traditional forms, the project systematically replaces materials in each component, aiming to reconstruct the teahouse space in alignment with contemporary construction techniques and sensibilities.