This explorative case study investigates health-promoting office design from an experience and meaning-making perspective in an activity-based flex-office (A-FO) in a headquarter building. This small case study (n = 11) builds using qualitative data (walk-through and focus group interviews). A reflexive thematic analysis (RTA) of the experience of design approach was performed on this from a health and sustainability perspective, including the physical, mental, and social dimensions of health defined by WHO. Results show a wide range in participants' experiences and meaning-making of the health-promoting office design of their office building. The control aspect plays a central role in participants' experiences, including factors such as surveillance and obeyance, related to status and power, in turn associated with experiences of pleasantness, symbolism, and inclusiveness. Three main themes are identified in participants' experiences: (1) comfort-non-comfort, (2) outsider-insider, and (3) symbolism. The major finding of the study is the ambiguity among participants about the health-supportive office design of the office building per se and its various environments. There is a sense that it is chafing, due to dissonance between the intention of the office and the applied design.