Nature is a database that offers potential solutions to humanity’s many problems with its countless living species and their developed adaptations. As in engineering, medicine, agriculture, etc., innovative approaches are sought in the discipline of architecture with the solution proposals offered by nature. Designers looking for creative solutions, especially in producing the most effective constructions with the most materials, providing energy efficiency in built environments, designing ecologically and harvesting water and developing methods that imitate and learn from nature. One of the main actors in the global agenda on climate change and the clean water problem is built environments. In this context, water harvesting methods to be developed through architectural design also emerge as one of the current research topics. In this paper, research has been conducted on how the water harvesting knowledge in nature can be integrated into architecture; A biomimetic shell proposal has been developed to provide atmospheric water gain. Firstly, the concept of biomimetics is clarified through a literature review and examples of water balance strategies of living things in nature are presented. Then, architectural examples inspired by these strategies are analyzed. The selected living organisms were analyzed in the field study section and a design concept that can harvest water on the building facade was developed based on the biological information obtained. Inspired by the water harvesting principles of cactus and Bromeliaceae plants, this design is presented as an alternative for water harvesting with different usage possibilities in built environments.