The Existing Building Energy Optimization workshop aims to provide more resilient energy optimization solutions for existing buildings to all stakeholders. This paper introduces the recently developed Existing Building Energy Optimization workflow, into which 3D laser building scanning and the BIM2BEM have been added in order to increase productivity over the time-consuming and labor-intensive conventional energy optimization processes for existing buildings. This paper also demonstrates model calibration and suggests feasible ECMs for the exemplary building. It is author's intent to share lessons from the workshop, that is, use of ICT tools will accelerate active collaboration between building service engineers and non-experts. Eventually the workshop workflow and lessons is used to formulate an educational curriculum of green building design and retrofit classes. Lastly the paper is enclosed with future research initiatives in developing an enhanced process or a harness toward the analysis-driven retrofit decision making. A value of these initiatives is found from increasing usability of the formalized expertise and appropriate localizations.