Despite implementing the continuous improvement and respect for people principles as understood from the current research, many lean transformations fail. This paper provides an argument that there is a missing yet important set of elements supporting these principles that needs to be understood. For many lean leaders and coaches a primary concern is obtaining the full engagement of everyone on a project team in lean practices. This paper recommends a new area for research and experimentation, tapping the holistic aspects of lean, not only as they apply to the enterprise or project, but also as they apply to the individual. It examines new ideas about how enthusiasm for lean can be methodically generated in the building design and construction industry. Borrowing from her work in business culture change, one of the authors (McGuffey) has developed a ‘legacy transformation model’ that identifies the elements at work in the early years of the Toyota Motor Corporation. The model was tested against prior research to determine if testing the model on building projects in a comprehensive manner is warranted; the results of which are reported herein. Further research requiring the commitment of project teams to pilot a lean transformation process based on the legacy transformation model is proposed.