Assessment of the impacts of building materials on the reduction of CO₂ emissions from high-rise commercial buildings in Hong Kong

¹ Department of Building Services Engineering, Faculty of Construction and Environment, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
² Department of Civil and Environmental Engineering, Faculty of Construction and Environment, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China

^* Corresponding author: a 18084072g@connect.polyu.hk
^b chi-kwan.chau@polyu.edu.hk

Abstract

Based on data collected in 20 A-level high-rise commercial concrete buildings in Hong Kong, the research successfully established a probability density function model, which is used to describe the carbon emissions profile of a commercial building. Results indicate that the superstructure of a commercial building, on average, had a footprint of 226.65 kg CO₂/m² and 10.6 kg CO₂/m² separately in the material use stage and transportation stages. It also evaluates the carbon emissions of various building elements and divides them into three levels according to the magnitude of their contribution. The results show that upper floor construction and external wall in Tier 1 contribute nearly 80% of emissions and should be of great concern. In addition to the probability density function model, a regression model was also successfully established in the study to predict carbon emissions. Research has shown that building layers and gross floor area can predict carbon emissions per unit area, and there is a positive relationship between the independent variable and the dependent variable. The regression model can help building designers determine design options to reduce carbon emissions in the early stages of design.