How Can Decarbonisation Alternatives Be Prioritised to Achieve Carbon Neutrality in Building Projects?

The built environment generates approximately 40% of the annual global carbon emissions. To achieve the Paris Agreement target towards net-zero emissions, timely and sufficient plans for emissions reduction in the sector need to be made. One of the optimal strategies to realize sustainable structures is to select decarbonisation alternatives that will present a holistic view of environmental impacts. This research effort examined how decarbonisation alternatives are prioritised to achieve carbon neutrality in building projects. Based on extensive semi-structured interviews with experts, this research identified energy, emissions, economy, and exergy (4Es) as the four critical variables considered when making decarbonisation decisions. These 4Es were then assigned to different evaluation criteria, resulting in a total of 27 evaluation criteria. These findings will assist built environment professionals to prioritise decarbonisation alternatives across the entire project lifecycle. It will also provide policymakers with new insights for assessing potential impacts based on these four variables.