The prefab Flood-Proof House built in area contains a small 1940 mid-century modern beach house on half of the lot, located near the San Andreas Fault. The client request to achieve maximum sustainability and minimum site alteration is addressed through innovative uses of structure and materials. Interlocking horizontal steel moment frame and truss system: this maximizes usable space above the flood level, cantilevering atop the wave-proof columns. The perpendicular steel truss enables the new house to cantilever over the existing house as a code exception to preserve the adjacent historic …