TY - CONF TI - Relating Non-Physical Waste in Lean Construction to Carbon Emissions during Project Execution C1 - Singapore, Singapore C3 - Proceedings of the 34th Annual Conference of the International Group for Lean Construction (IGLC 34) SP - 547 EP - 557 PY - 2026 DO - 10.24928/2026/0274 AU - Gazali, Abdhy AU - Nugroho, Muhammad Sapto AU - Nachdy, Wildan AU - Nurrahmawati, Annisa AD - Lecturer, Building Engineering Education, State University of Jakarta (UNJ), Indonesia, abdhy.gazali@unj.ac.id, orcid.org/0009-0004-1391-6533 AD - Lecturer, Civil Engineering Department, Universitas Trisakti, Indonesia, m.sapto@trisakti.ac.id, orcid.org/0009-0002-4563-6099 AD - Manager Environment & Health, QHSE Division, PT PP (Persero) tbk., Indonesia, m.sapto@trisakti.ac.id, orcid.org/0009-0002-4563-6099 AD - Student, Building Engineering Education, State University of Jakarta (UNJ), Indonesia, annisaunj002@gmail.com ED - Hamzeh, Farook ED - Poshdar, Mani ED - Garcia-Lopez,, Nelly P. AB - Lean Construction has been widely applied to improve efficiency and reduce waste in construction projects; however, its relationship with carbon emissions remains predominantly examined from material-based perspectives. This study explores how non-physical waste in Lean Construction such as waiting, downtime, and making-do relates to carbon emissions during project execution. This study employs a structured literature review to synthesize research on Lean–Green construction, focusing on relationships between process-based waste, waste-related outcomes, and carbon-generating activities. The findings indicate that non-physical waste contributes to carbon-relevant impacts through time-based and process-related inefficiencies, including extended activity durations, idle equipment operation, and repeated processes. Rather than causing direct material loss, these waste mechanisms indirectly increase the intensity and duration of carbon-generating activities. As a key contribution, this study proposes a structured analytical framework, including a generalized proxy formulation, to relate non-physical waste to carbon emissions based on additional operational time and activity-level carbon intensity. The framework complements existing material-based carbon assessments and provides a basis for future empirical validation. KW - Lean Construction KW - Waste KW - Carbon footprint KW - Green Construction PB - T2 - Proceedings of the 34th Annual Conference of the International Group for Lean Construction (IGLC 34) DA - 2026/06/22 CY - Singapore, Singapore L1 - http://iglc.net/Papers/Details/2562/pdf L2 - http://iglc.net/Papers/Details/2562 N1 - Export Date: 19 June 2026 DB - IGLC.net DP - IGLC LA - English ER -