i guess that would depend on your graphics card i use a gtx 1050 ti with a i5,all separate scenes  so u can use a toggle system to turn one off and one also i tried building them into one scene but since they were made seperate,the lighting  conflicts with the other scenes.i have a little hospital game u can try out https://gamejolt.com/games/HospitalWalkingDemo/985594, it uses a toggle ui button to toggle one scene off one scene on 

gtx 1050ti i5-4570  and 16gb ram ....hallway 39fps, bathroom 21fps, living room 21fps bedroom 18fps kitchen 23fps,front house view 40 fps,