New ways of working with a flexibilization in time and space are characteristics of today’s office world, but at the same time stress-related health problems are on the rise. Nature contacts is shown to be a resource for health, and outdoor offices were invented to combine both flexible working and health resources at the workplace. As outdoor office work (OOW) is quite new and little is known about its usage, the aim of the study was to deepen our understanding about what circumstances lead to the consequence, that employees do not conduct office-related work tasks outdoors, even if they have access to outdoor spaces and green areas. Following research question was about to be answered by a grounded theory study: What factors hinder office workers to conduct office-related tasks outdoors? The data collection was conducted in 9 semi-structured online interviews and 3 phones calls with participants from Sweden, the Netherlands and Germany. The theoretical model was constructed through a process of coding and memo writing. The results show a theoretical model that entails one core category, Norms, and three main categories, Personal Factors, Organizational Factors and Practical Issues. The categories act interdependent, whereas existing norms have the most powerful impact. Work is perceived as something that should be conducted indoors at a desk, and as something that is stressful and can be inconvenient. The existing norms of how to conduct office work are influencing personal, organizational, and practical factors that lead to the consequence that employees do not conduct office work outdoors. The findings of the study provide useful knowledge for further research in the field of OOW, as well as for organizations that want to implement an outdoor office.