We are very excited to officially launch of the Open Source Building Science Sensors (OSBSS) project! The goal of OSBSS is to develop and document the design and fabrication of a network of inexpensive, standardized, and synchronized measurement devices for recording long-term indoor environmental and building operational parameters that are likely to influence microbial diversity and abundance in indoor environments. Documentation of the development, calibration, and performance of the sensor network will utilize open source hardware so anyone in the world can build their own sensors and sensor networks.