The difference between experiencing biological time and technical time is a reflection on an existing problem in society. In a hospital, these two times come together and collide. Biological time is the personal rhythm of both employees and patients. Technical time is witnessed in the strict schedule of the hospital, necessary to facilitate the complex set of actions that take place in a highly technological surrounding. But our bodies, which are the focal point of the hospital, live in a strong connection with the biological rhythm. Some illnesses are caused in part or exacerbated by the rhythm of time in the western world. Within the medical world, time is used more and more as a solution, as in the case of chronotherapy. But still a hospital functions mainly according to technical time – visitor times, staff shifts etc. As designer it is therefore interesting to introduce biological time to the hospital environment, where technical time is dominant. The biological rhythm is visible outside the hospital: trees, plants and animals all live outside the rhythm of technical time. Most hospitals are positioned at the borders of cities, where urban environments meet the rural surroundings, rich in biodiversity. Biological rhythms depend on the changing of the seasons. They often influence illnesses: light, temperature and other factors influence the progress of an affliction. As a designer I intend to introduce these natural rhythms, so they can become part of the hospital’s system. On the border of inside and outside, the hospital façade, biological rhythms can be given space and visibility. It directly links actions inside and outside the hospital, and allows outside rhythms to be experienced by the patient in his bed, connecting technical and biological times of both zones. Design concept: Can the biological rhythm be introduced into the hospital in a meaningful way, without entailing chaos? I want to attach nest boxes to hospital facades. These nest boxes provide space for animals, living according to biological time. By making biological time visible from within the highly technical hospital, synchronization can take place and attention is drawn to differences between the rhythms. The nest boxes are of specific dimensions according to species and position on the hospital building. As the hospital itself is divided by departments, interesting overlaps and collisions can take place.