The notion of Life-Cycle Costing (LCC) is generally recognized as a valuable approach for comparing alternative building designs - enabling operational cost benefits to be evaluated against any initial cost increases. However, a host of practical difficulties conspire to limit its widespread adoption. This limited acceptance is particularly important in green building where many of the benefits of strategic choices can often only be understood and justified when cast in a life-cycle context. This paper identifies some of the critical gaps between the theory (and promise) and practice of Life-Cycle Cost analysis to discover strategies that encourage greater use.