Urban population growth predictions and the threats posed by climate change will exacerbate social problems such as equal access to water worldwide. This will happen mostly in developing countries and will couple with other environmental issues such as the intensive use of raw materials and the production of new waste. New solutions need to be thought and atmospheric water supplies such as fog or dew water represent alternative sources still largely untapped. Within the Living in a Bottle project, this research looks at computational design workflows and Additive Manufacturing as tools that can play a role in mitigating these risks, while transforming the perception of plastic waste from burden to construction material. Moreover, 3d-printing represents a flexible fabrication technology that could play a relevant educational and developing role in growing communities. The goal of the research is to propose a solution for a mono-material building envelope component designed to enable and maximize atmospheric water collection in developing countries. The design aims to be adaptable to different climatic scenarios and easy to replicate locally. The task is approached systematically by defining all necessary functions and exploring the best strategy for each of them. Every step is performed considering both the optimization of functionality and 3d-printability. Functions are then combined in one element which is prototyped and tested. Computer simulations for the city of Rabat (Morocco), show that the combination of a dew and fog collector in one component would reduce by half the surface required to fulfill the water needs of one person. A feasibility analysis is also performed and the price of one module is estimated. The result is comparable to the cost of standard solutions in the field of atmospheric water harvesting and represents therefore an interesting achievement in the development of such technology.