System Boundaries of Total Factor Carbon Productivity for Construction Projects

Stabilizing atmospheric greenhouse gases and maintaining economic growth are two objectives of the urbanization process. Reconciling them means “carbon productivity”. Despite the burgeoning body of knowledge on measuring total factor carbon productivity (TFCP) at the construction industry level, TFCP of construction projects had never been made explicit systemically. The contradiction between the relative concept of TFCP and the uniqueness of construction projects caused the “comparing apples to pears” syndrome in unifying the conceptualization and identifying the parameters to analyze and improve TFCP of construction projects. All these suggest a significant knowledge gap in effectively addressing the complex socio-technical features of construction projects’ TFCP. Thus, this study aims to fill the gap by formulating system boundaries of TFCP for construction projects. The model elaborates the boundaries of construction projects’ TFCP in four dimensions with 11 system boundaries: policy timeframe, project timeframe, climatic, urbanization, carbon emission, energy supply, stakeholder, parameter, project typology, density, and business sector. The boundaries are validated through multiple real-life cases in Chengdu, China. This paper concluded that although the boundaries are described separately, they are dynamic and interactive. The findings also indicate that the TFCP of construction projects should be regarded as a complex socio-technical system, and the proposed boundaries should facilitate the paradigmatic improvements in the knowledge of construction projects’ TFCP.