A system framework of the cost and energy relationship of zero carbon buildings from the life cycle perspective

Zero carbon building (ZCB) has emerged as an innovative approach to addressing the shortage of energy supply and carbon emissions from the building sector. The majority of ZCBs worldwide are mainly driven by government policy, some with financial incentives. In such cases, the social and environmental benefits of ZCBs are prioritised over their economic efficiency. Previous studies of ZCB were largely technical solutions oriented; some examined the impacts of zero carbon design solutions on the building's economic efficiency. However, there is a lack of exploration of the cost and energy relationship of ZCBs. The aim of this paper is thus to develop a system framework of such relationship of ZCBs from the life cycle perspective. The research was carried out through a critical literature review. The life cycle approach was adopted to examine the scopes of costs and energy consumption of ZCBs. A system framework is then developed to indicate how to define the scopes of costs and energy consumption of ZCBs and elaborate how to further proceed to the examination of their relationships. The system framework embraces two layers, i.e. internal and external layers. The internal layer illustrates the interior relationships between the cost, energy and lifespan of ZCBs through a three-dimensional conceptual model; the external layer describes outside context including stakeholder, climatic context and regulatory context. The results of the review suggest that there is a significant extent of inconsistency in defining the scopes of both costs and energy consumption of ZCBs. That is attributed to the confusion and dimness in the definition of both buildings' costs and energy consumption. Such inconsistency hinders the cost-energy relationship from being revealed. The findings should inform the building design decisions about the trade-offs between buildings' economic efficiency and carbon emissions.