When Roger Ulrich demonstrated in 1984 that hospital patients whose rooms overlooked trees recovered faster than those facing a brick wall, he inaugurated the field of Evidence-Based Design (EBD). The nurses whose observations he used as data appear nowhere in his conclusions. This thesis argues that this omission was not incidental: it was foundational. EBD emerged in hospital architecture as an exclusively patient-centered methodology, and the deliberate exclusion of staff from its research frame formalized in the Center for Health Design's 1998 report shaped the field for more than two decades. Only when empirical research established that staff wellbeing was associated with patient safety outcomes did workers become legitimate subjects of architectural inquiry. This shift, traceable between the 1998 report and Joseph's 2006 staff-focused publication, constitutes the mechanism by which EBD was transformed from a healthcare-specific tool into a methodology applicable to all workplaces. Tracing this transformation through industrial legislation, office design discourse, and hospital architecture, this thesis proposes a new account of how worker wellbeing became an architectural concern: not through a progressive expansion of humanistic values, but through the instrumental logic of measurable evidence. ... Read more