Modelling gaseous emissions from energy consumption during building life cycle

It is well known that building and construction contribute a large part of emissions to the environment, and it is estimated that worldwide, the buildings and constructions sector is the second largest global carbon dioxide (CO2) emitter after industry, representing approximately 33% of the global total. Therefore, improving sustainability performance through mitigating emissions in construction has become a pressing issue. This paper divides any building's life cycle into seven elements: i) manufacture of building materials; ii) transportation of building materials; iii) construction; iv) operational life; v) maintenance and repair; vi) demolition; and vii) disposal of construction waste. We define eight types of gaseous emission during a building's life cycle: CO2, CH4, N2O, SO2, CO, NOx, NMVOC and particulates. The paper analyzes the sources of gaseous emissions and presents a model for calculating the gaseous emissions during a building life cycle with particular reference to Hong Kong. The model helps evaluate the impact of building projects on air quality, from which strategies can be devised to reduce its environmental impact during a Building Life Cycle. A preliminary review of a case study of the construction stage is also discussed to show an application of the developed model.