This study was aimed at developing a design guide for stress reducing healthcare facilities for people with a chronic disease and their caregivers. This study was conducted with literature research, interviews and analyzing reference projects. The results of the literature research show the impact of stress on the different users, the importance of informal care in the Netherlands and proof that stress can be reduced by architecture in the healthcare environment, for all users. The interviews resulted in six psychosocial needs that where translated to a set of design principles with use of the reference projects. These design principles can be used as a design guide. A sustainable and stress reducing radiotherapy clinic was designed in Leeuwesteyn, Utrecht, implementing the design principles from the research. With multiple care functions, divided in three departments, the building foresees in all care needed (mental, physical and medical care). Main concepts are a clear routing, four atria and a nice view on greenery. Separate routings for employees and visitors, and a separate space for all the users are making this building stress reducing. Daylight is guaranteed in all spaces without depriving the privacy, with the use of special façade materials as metal mesh and vertical bamboo slats. Therefore, the building is a stress reducing environment for care without worries.