This paper summarizes results from the first phase of a study to evaluate the lateral resistance of wood based shear walls without openings, built with regular and nonstandard large dimension oriented strand board panels under monotonic and cyclic loading conditions. Furthermore, different types and spacings of panel-frame connectors were investigated. Results of the second phase, which considered shear walls with openings, are presented in a subsequent paper. The results of the first phase indicate that under monotonic loading, a substantial increase in both stiffness and lateral load carrying capacity, as well as comparable ductility ratios, can be achieved by shear walls built with oversize panels, compared to regular panels. The walls built with regular panels, however, were found to dissipate more energy under cyclic loading than the walls built with oversize panels. The failure modes were substantially different under monotonic (nail withdrawal) and cyclic (nail fatigue) test conditions, which raised the question as to whether the adopted cyclic loading schedules realistically represent the loading sequence expected under wind and earthquake loading.