I love this concept! Would be interested in seeing the details on how the Gantt chart was done. It would be a great tool to actively schedule our classes.
Would definitely be interested in discussing more with you! I am presently working on a project trying to visualize space utilization (mainly classrooms at this time).
You need a scaffold/skeleton table to be able to visualize when no one is using the room.
I went to this session at TC 18, solving tough time-based problems with skeleton tables and tableau prep, and it shows how to do this with tableau prep.
The workbooks are here: https://tc18.tableau.com/learn/sessions/32203
I've just completed a project where we compared room occupancy, based on sensors, to room schedules in order to get a feel for when rooms are in use but not scheduled, when rooms are scheduled but not in use, when rooms are available, etc. Can't really show specific examples here, but would be happy to chat with anyone who might be interested in it. Most of the hard work on this project was the data architecture. It's not a straightforward problem to compare random occupancy times to scheduled times, so it involved a lot of up front data work before it could be brought into Tableau.
I've done some extensive work on this for UC Davis. I can't share it because they don't want to post it publicly, but I can share some of the highest level PDFs that I generated and can also help anyone who needs assistance in getting started. My email address is email@example.com or you can contact me through the forum.