<p dir="ltr">Work from home (WFH) moves work into home life, reshaping the residential, workplace, and commuting activities, which further impacts greenhouse gas (GHG) emissions. Although existing work has explored individual time-use patterns under WFH, there is a lack of complete consideration of diverse activities, their durations and timelines, as well as the comparisons with traditional life at home and Work in Office (WIO). Also, existing studies have examined GHG emissions under WFH, while individual-level estimation using activity-specific data covering all major activities is lacking. In particular, limited studies explored individual time-use patterns and quantified activity-based emissions for the construction workforce. Therefore, this dissertation aims to (1) develop an activity-based individual-level model to estimate GHG emissions under WFH, (2) compare individual time-use patterns and activity-based GHG emissions between traditional life at home, WFH, and WIO to understand how WFH affects work, life, and the environment, especially for the construction workforce, and (3) propose activity-based decarbonization strategies to reduce GHG emissions. By employing the proposed model, high-resolution calculations of individual time-use patterns and activity-based emissions were achieved, revealing major activities’ durations and timing and highlighting major contributing activities to emissions under WFH. When shifting from traditional life at home to WFH, individuals reduced sleeping and leisure hours to incorporate work activity, resulting in an 11.34% reduction in GHG emissions. When comparing WFH to WIO, individuals reduced work and commuting time to include more cooking and leisure activities at home, mitigating GHG emissions by 29.11%. Demographic groups and climate regions showed different results mainly because of the varied work and household duties and the characteristics of regions. In addition, the construction workforce reduced GHG emissions by 13% and 46% under WFH compared to traditional life at home and WIO, respectively. Compared to the general public, the construction workforce had more reduction in work and commuting hours and associated emissions when shifting from WIO to WFH. The findings could help envision how WFH influences work, life, and the environment as well as assist both individuals and policymakers in achieving decarbonization and adopting low-carbon living during the work arrangement transition, which could contribute to sustainable development.</p>