Multiple rooms (spheres) with different entrances/exits

I'm creating a tour application with multiple videos for users to see. People move from one video (or one room) to the next by clicking a hallway or door. This sounds like a lot of custom work creating objects in Maya/Builder though to create buttons shaped like the hallways/doors. I just want to make sure I'm on the right path.

• Is this going to require manual work for every room? Is that how video games do it too?

• Is each room a new scene in Unity? Or can I put multiple rooms in one scene and move the camera?

Thank you for the advice!