R+C was structural and geotechnical engineer for this American Institute of Architects (AIA) landmark house rehabilitation. The project involved an innovative structural scheme center coring masonry chimneys, strengthening wood walls, and adding new foundation elements. R+C developed a full-sized prototype of a strengthened wood wall for dynamic testing to simulate San Andreas Fault activity. R+C Geotechnical developed conceptual studies for and restored retaining walls within the Hanna House site. Built in 1937 and exemplifying Frank Lloyd Wright's unique contribution to American culture, it was Wright's first use of a hexagonal design module and one of his most sophisticated Usonian projects. The building was badly damaged by the Loma Prieta earthquake. The rehabilitation was accomplished under the guiding principle that the restored house should look untouched from its original design.