Saving build light result

Hi all,
I am creating an Archviz game with two design options for bedroom. Each option included different furniture layout. I use sub_level to device 2 options and exclude objects from being build lighting. The problem i have is when i turn on both sub_level and build, the shadow from objects in option A still appear when i want to play option B and vice versa.
When i try to turn off A option and build lighting, B option look well but A option is not good, the lighting is not be build, then the wall is dark grey. Can i save build lighting result and load this for every option? Or do anyone have any suggestion to solve this problem ?Please share with me if you have. Thank you.