Despite a centuries-old call for the incremental care of historic sites, stewards remain challenged to embrace a proactive philosophy for building preservation. This philosophy, termed “preventive conservation,” is not only a technical strategy for enabling the long-term preservation of historic resources, but is also an effective approach to historic site management. Through semi-structured interviews with thirteen stewards of historic sites across the United States, this thesis addresses the question: how can organizations build sufficient capacity for successful implementation of preventive conservation? First, the pursuant analysis reveals that capacity for preventive conservation is limited by inconsistently applied terminology, both within and across disciplines. Second, interviews demonstrated that stewards are overwhelmed by deferred maintenance, a perceived barrier to implementing preventive conservation. By clarifying the definition of preventive conservation and acknowledging its relationship to deferred maintenance, this thesis proposes a process for organizational change that guides stewards from deferral to a sustainable state of prevention.