Zero-carbon renewal of communities through collaborative retrofitting of multi-scale design elements: A case of Wuhan, China

Zero-carbon renewal of the existing communities is an ideal option for achieving carbon neutrality in the stock era. However, most of the studies on retrofitting existing communities are quantitative in terms of energy facilities and enclosure structures, only seldom considering communities as a whole, which makes it difficult to achieve the goal of zero-carbon renewal of communities. In order to explore the possibility of realizing zero- carbon renewal of communities, this study proposes a methodology for collaborative retrofitting of multi-scale design elements to achieve zero carbon in communities. This study presented 15 prototypes from 126 real communities and then generated 243 representative transformation scenarios by aggregating the muti-scale design elements at three scales (community-building-facade). Through correlation and sensitivity analyses, key design elements were identified, and a prediction model of carbon emissions was constructed. The findings suggested that the degree of influence of multi-scale design elements on the communities carbon emissions was 132%. The building operation carbon emission accounted for 59%, the carbon reduction of solar energy accounted for 35%, and the greening carbon sinks accounted for 6%. Floor area ratio, green ratio, building density, south window-to-wall ratio, east-west window-to-wall ratio, heat transfer coefficient of external wall, and shape factor were the key design elements. This study provides a new perspective for the renewal of zero- carbon communities around the world, it also provides key design elements and design strategies for policy- makers and designers to realize zero-carbon renewal of communities.