An Urban Renewal Design Method Based on Carbon Emissions and Carbon Sink Calculations: A Case Study on an Environmental Improvement Project in the Suzhou Industrial Investment Science and Technology Park

In the process of urban renewal, the high carbon emissions caused by pollution from construction waste and the consumption of materials and energy via "demolition and construction" present significant problems. Calculating carbon emissions and sinks is a prerequisite to carving out a low-carbon path via urban renewal. In this paper, we take an environmental improvement project in the Suzhou Industrial Investment Science and Technology Park as an example. Under the framework of the entire life cycle, we define the "renewal phase", which includes "demolition" and "construction", as the calculation boundary, and use the emission coefficient method as the primary calculation approach to assess carbon emissions and sinks. We construct a design-oriented carbon revenue and expenditure estimation system based on the BIM model. After its application in empirical cases, the results show the following: (1) The building carbon emissions of Scheme A are 342 t higher than those of Scheme B, due to the fact that the "demolition and construction" works in the former increased by 6000 m2 compared to the latter. (2) The landscape carbon emissions of Scheme B are 269 t higher than those of Scheme A, due to the addition of a 2500 m2 reinforced concrete overhead walking platform. (3) The annual carbon sink of Scheme A is six times higher than that of Scheme B, due to the fact that the number of trees and shrubs in the former is five-to-six times greater than in the latter. The number of trees planted plays a decisive role in enhancing the carbon sink benefit. (4) In the year during which the renewal project was implemented, the difference in carbon emissions between Scheme A and Scheme B was 72.9 t. By the 16th year, the difference in carbon emissions between the two schemes approached zero, and the carbon reduction advantages of Scheme A became more pronounced over the entire life cycle thereafter. Finally, this article summarizes four low-carbon design strategies for industrial park renewal projects: rational construction and demolition, three-dimensional parking, low-carbon materials, and plant carbon sequestration. In the context of inventory renewal, this article makes a significant contribution in terms of carbon footprint control and the "dual-carbon" goal.