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