International Industrial Ecology Day 2021

Traditionally, ‘bottom-up’ material flow analysis studies of the built environment have typically had spatial scopes of neighbourhoods, cities, and countries. However, ambitious net zero targets from construction companies and/or governments require deeper understanding of material use and environmental impacts, particularly embodied carbon, at the individual asset level. At this level, building construction projects involve various stakeholders that contribute to decision making. This information flow is increasingly being digitalised, and here building information models (BIMs) are playing a pivotal role. Realising the increasing importance of these two aspects in environmental assessments of the built environment, stakeholder management and BIMs, we set out to comprehensively understand the relationships among stakeholders and drivers of embodied carbon in individual construction projects. Here, we present our approach and progress towards achieving this aim, through a study of the construction of a multi-purpose high-rise university building, from planning to design, construction, and delivery stages. This includes aligning BIM driven-material intensity factors with specific construction stages, revealing responsibilities of different stakeholders (contractors, subcontractors, procurement, other supply chain actors) in the overall environmental impacts of the construction projects, and identifying user expectations for building functionality and relating how they affect the design briefs and in-turn material and component specifications. Based on the distribution of construction tasks in the project, we associate costs, materials, activities, and eventually environmental impacts with the different stakeholders. Overall, this study improves understanding of individual construction projects, notably the embodied carbon burdens of each project stakeholder, and provides specific strategies for decarbonisation at this level.