"Active learning classrooms" are purpose-built learning spaces designed to facilitate active learning strategies. While sometimes constructed as new rooms, active learning classrooms may also be retrofit from existing learning spaces. The ongoing evaluation of active learning classrooms helps to generate new research insights, pedagogical practices, and refinements for teacher training. While perception studies are well-established as research methods within the evaluation of ALCs, this article provides a novel methodological contribution by applying a positive/negative study framework to an instructor survey distributed in an institution with an established history of evaluating ALCs. We find that this approach enabled new insights into expected findings: that ALCs are best used when expectations are matched to the specifications of the built environment, that low-tech ALCs foster social interaction, and that "shadow zones" in retrofitted rooms may introduce physical barriers to teaching and learning.