As a part of an overall effort to achieve optimal energy efficiency, Miyamoto combined efforts with Green One Construction, the Oregon Department of Energy, and the Energy Trust of Oregon to test the structural sheathing over a rigid insulation lateral system. In acknowledgment of the fact that this system is not a prescriptive lateral system identified in the IRC or IBC, we specified that a rigorous seismic cyclic testing program be implemented which was performed by Oregon State University. As a result of our work combined with others, the system has been approved and is in use for the Net Zero Sage Green project. It was determined that the Ply over foam system was the most economical way to achieve the R33 wall system, a requirement based on the energy modeling.