Evaluation of the impact of urban morphology on commercial building carbon emissions at the block scale – A study of commercial buildings in Beijing

With the rapid development of cities, the proportion of building carbon emissions in the total carbon emissions of cities is increasing, and the carbon emission intensity of commercial buildings is higher than that of other building types. The relationship between commercial building life-cycle carbon emissions and urban form factors at the block scale and the spatial differentiation of building carbon emissions in commercial blocks remain unclear. In this study, a calculation method for building life-cycle carbon emissions in urban commercial blocks was established using (1) GIS technology to establish a commercial district building model and urban form factors and (2) block model classification according to architectural layout and combination as well as typical layout pattern extraction through morphological type. Additionally, (3) building life-cycle boundary and scenario parameters were determined, and the urban modeling interface (UMI) platform was used to numerically simulate block samples and typical layout modes for carbon emission calculation model construction. Beijing was chosen as a calculation and analysis example. The results indicated that building shape factor (BSF) is an important indicator of carbon emissions and that the impact of building density (BD) on carbon emissions is two-sided. The spatial differentiation of carbon emissions is obvious, which could provide effective suggestions for target building planning. By studying carbon emission indicators under typical layout modes, we found that low-rise building + tower-enclosed (L + T-E) and low-rise building + tower-determinant (L + T-D) are the best layout modes.