There has been an increase in interest in healthy indoor environments over the last decade. WELL is currently the most comprehensive building certification system that aims to enhance human health and well-being, but little research has been published on the impact WELL spaces have on their occupants. This research examined three locations of an architecture and design firm that moved from offices that were not designed with WELL strategies to offices that were. Pre- and post-occupancy evaluations were conducted to understand the impact spaces designed with WELL strategies have on their occupants’ satisfaction with IEQ and perceived health and well-being. Results suggest that implementing WELL design strategies in the workplace can lead to increased employee satisfaction with IEQ, improved employee perception that their workplace is conducive to health and well-being, and better employee self-reported mental health.