Comparing the Standards of Life Cycle Carbon Assessment of Buildings: An Analysis of the Pros and Cons

Abstract

Buildings play a substantial role in carbon emissions and contribute to approximately 37% of global carbon emissions. In order to control and reduce the carbon emissions of buildings, a report of life cycle carbon assessment (LCCA) has been mandated for all the new buildings in China since 1 April 2022. As a technical support for carbon accounting efforts in China, it is important to adhere to the national standards for conducting an LCCA report. In this context, the GB/T51366-Standard for Building Carbon Emission Calculation is the designated national standard that should be followed. However, GB/T51366 has several deficiencies, including incomplete life cycle processes, impractical calculation methods, the unrepresentativeness of default emission factors, and so forth. Therefore, it is essential to critically analyze the pros and cons of employing an LCCA methodology adhering to GB/T51366. To fulfill the research aim, this study develops a computational toolkit based on GB/T51366. We propose two data collection methods and conduct a case study of a residential building in China. GB/T51366 was also used as the baseline scenario and compared with the European standard EN15978. The results show that GB/T51366 is less comprehensive than EN15978, leading to a 2.9% reduction in the total life cycle emissions. Notably, up to 26.7% difference was observed in the comparison of the emission factors of the main construction materials. Based on the research outcomes, it is suggested to improve the national standard in terms of the scope and data availability, as well as to promote the harmonization of existing national LCCA standard of buildings with international standards.