JAUE2024-055: Research on Embodied CO₂ in Buildings Method for Estimating CO₂ Emissions at the Design Stage

Abstract

In order to evaluate a carbon-neutral building, it is essential to assess CO2 emissions throughout the life cycle of the building, including construction, operation, and demolition. Although there are currently several initiatives regarding operation, little attention has been paid to CO2 emissions generated during construction, which are said to be equivalent to 15 to 20 years of CO2 emissions during operation. In addition, large buildings are being constructed as part of redevelopment projects in major cities, but the CO2 emissions generated during this process have been overlooked as a serious problem, in contrast to the large numerical value of the emissions.

In this study, a detailed evaluation of CO2 emissions is conducted for several existing buildings. Based on the results, the objective is to propose a system that allows consideration from the planning stage of how much CO2 emissions can be expected as a result of building construction.
First, four properties will be selected for evaluation and CO2 assessment. The selected buildings are public buildings such as government buildings and libraries. Next, based on the evaluation results and existing intensity data, we propose a system that enables the planning stage to assume and consider how much CO2 emissions will be emitted during construction. In two stages, the "planning stage" and the "basic design stage," a study is conducted to estimate the amount of CO2 emissions based on the assumed building data.

As a result of the rough estimation by the two proposed methods, we were able to calculate values close to the results of the detailed evaluation in both patterns. In the future, we will increase the number of properties for detailed evaluation and enhance the basic data on the evaluation sheet to improve the accuracy and proceed with the analysis so that it can be used more universally.