In summary, we report an open-source aging chamber design, designed for high-throughput, semiautomated stability measurements of perovskite samples. This article is structured as follows: First, we establish the design principles of the environmental chamber and present evidence for perovskite color change being a suitable proxy for perovskite degradation, and determine the limits of proxy validity. Second, we describe the chamber versions. Third, we discuss our process of open-hardware dissemination between three different laboratories, and identify principles that may facilitate similar efforts in the future. By firstly sharing all the three designs and secondly discussing the development process itself, we hope to encourage wider adoption of specialized open-hardware efforts in materials research, and facilitate further evolution of this environmental chamber design in new applications and laboratories.