This master thesis presents an architectural design proposal for a forest kindergarten for children between three-six years with and without an ADHD diagnose. Designing for this specific user group requires an understanding of the problematics they are facing in their everyday life in order to create architecture which enhances and supports their physical,- social- and cognitive development – this with the approach of playful learning and understanding how the light affects biological processes in children. The thesis approaches sensory stimulations, light and sustainability from both qualitative and quantitative perspectives as a generator for the experienced quality of the space. The design proposal provides a variety of different spaces for the children to evolve through play in close relation to the calm surroundings of nature.