Stemming from a departmental grant to fund new environmental design teaching tools, the Fabrication Lab designed and built a custom mirror-box style artificial sky. This generates a physical simulation of daylighting conditions for scale architectural models in order to measure Daylight Factor, a key metric of natural lighting in building interiors. This instrument mimics a perfectly overcast sky and can accommodate large scale models with an interior dimension of 2.5m x 2.5m.