Hi All,
After taking help with the discussions here, on the unreal forum, these are the additional things tried:
- Using multiple doors with different opening and closing delays and different opening angle (done using blueprint, extending our lecture blueprint) (Using this forum discussions- thanks to all)
- Using multiple trigger volumes, one for a room, each having its own threshold for opening some door. (Using lecture knowledge)
- Pawn overlapping one of the trigger volume is used to toggle light control for one room and turn off light after a delay. (Using unreal forums, google)
- Using concept of material instance from this forum to create instance of hex pulse roofing for both rooms which are parameterized on U-V values. (Using this forum and unreal documentation on material instances)
Here is the game play. Any general feedback will help! thanks. The second room has a glass in front of the door 
so you cannot escape through that!!