A dialectical system framework of zero carbon emission building policy for high-rise high-density cities: Perspectives from Hong Kong

Abstract

Several countries and cities have developed policies on zero carbon emission building or the alike as a driver for achieving sustainable development, which however mainly target houses and low-rise buildings. High-rise buildings in high-density urban built areas are generally perceived impossible to achieve zero carbon emission, and remain as a gap in policy study. Nevertheless, given the continuous rapid urbanisation, building higher and denser becomes the norm for many cities due to scarce developable land resources. This paper aims to develop and verify a dialectical system framework of zero carbon emission building policy for high-rise high-density cities focused on Hong Kong which is a typical high-density metropolis with the largest number of high-rise buildings in the world. The research was conducted through a questionnaire survey, follow-up interviews and focus group meetings, which together engaged over one thousand professionals and stakeholders selected using clustered and random sampling. The developed framework emphasises the interdependency between the technical elements of the policy within their complex and interactive socio-economic, geographical, and regulatory and political boundaries. For the technical elements, the zero carbon emission targets and timelines for Hong Kong were perceived very ambitious but can prioritise new public non-residential buildings. User behaviour and energy efficiency were considered critical given the limited renewables in the city. The boundaries of the policy should be clearly defined to address different contexts and stakeholders. A strong need was identified for formulating zero carbon emission building policy for Hong Kong, which however was perceived difficult to implement. The identified strategies should inform the practice of reducing high-rise buildings’ carbon emissions and thus achieving urban sustainability. The findings verify zero carbon emission building policy as complex dialectical systems and provide useful learning for such policy development in high-density cities.