Load new Umap ahead of time (Not Level Streaming)

Its common in 2D games to experience a game frame by frame.

Im interested if its possible to do something similar with my 3D game. However I can only find options that involve level streaming which seems to be a very inefficient way to achieve this. I want to be able to build lighting individually per map and have the ability to easily switch out maps for others. In a 2D engine I would just build multiple rooms and switch between them. However in 3D I need to be able to start loading in the room before switching to it, to remove load times. Its seems like this should be a simple tool in UE4 but Im having a lot of trouble finding it.

Thanks

You can define the volume where the streaming starts so level streaming would be the way to go, see this quick video for a smaller example.