A reconfigurable interior sidewall system includes one or more simply curved sidewall panels, each curved around the fuselage but longitudinally linear and providing a consistent mating surface for monuments. Panel openings are provided in each panel so that inner window assemblies may be installed for opposing structural windows, each inner window assembly having outward sculpturing for additional cabin room. A cover plate is also provided for flush insertion into the opening to fill the opening when it is not needed and to provide a constant profile for cabin monuments whenever the layout of the cabin changes. This results in the production of fewer parts as well as facilitating faster and less expensive interior reconfigurations.