Paradoxical Feasibility of High-rise Zero Carbon Buildings

Abstract

Zero carbon building (ZCB) has emerged as a most innovative approach to addressing anthropogenic climate change, evidenced by at least the relevant policy formulation and project deliveries in many countries. However, such approach only prevails in contexts where low-rise buildings dominate, while delivering high-rise towards zero carbon is normally arbitrarily perceived to be infeasible, substantiated by the lack of knowledge of high-rise ZCB and worsened by the absence of systems approaches to examining feasibility. This paper aims to contribute to a better understanding of the feasibility of high-rise ZCBs using a paradoxical framework. The research was conducted through the integration of a literature review of ZCB related research and practices worldwide and a study of the five-fold feasibility of high-rise ZCB in Hong Kong. This five-folder feasibility covers the technical, commercial, supply chain, regulatory and socio-cultural aspects. Two real-life high-rise buildings, residential and office, were used to develop energy simulation and carbon estimation baseline models for sensitivity analyses. The results indicate potential of reductions up to 57% energy use and 58.3% carbon emissions of the case buildings based on quick-win and optimisation design solutions and of nearly net-zero with strategic scenarios. However, such technically feasible solutions and scenarios are found to be institutionally difficult if not entirely infeasible. The five-fold feasibility is revealed to be interactive, dynamic and value-laden, with the specific aspects subject to their systems boundaries such as energy and carbon scope and calculation methodology. The resultant solutions and scenarios will inform future practices of reducing building energy and carbon emissions. The contributed paradoxical framework challenges conventional perceptions on feasibility and will guide the quest for high-rise ZCBs as complex socio-technical systems as they are.