This study analyzes instructor attitudes toward 26 collaborative spaces at a large, R1 university in the United States. The authors conducted 151 interviews with instructors, identifying elements of classroom spaces that helped or hindered teaching and student learning. Approximately 44% of the instructors (n=67) had participated in a professional development program designed to encourage and enhance student collaboration and active learning in courses. A comparison between that group and all other instructors in this study (n=84) showed instructors who had participated in the development program stated fewer hindrances to their teaching.