Best methods for specifying which objects get lightmapped?

Hi all, I have a question about “best practices” for controlling which objects do or don’t get lightmaps baked.

I’m working on a project where the majority of the world is outdoors, and has a changing time of day, so I’m not baking any lighting there. But there are some other areas that are indoors or underground, and I want to lightmap those areas instead.

What’s the best way to insure that when I hit that “Build” button, that lightmaps are only being generated for the objects that I specifically want to be lightmapped, and that the other objects are not wasting processor time or building unneeded lightmaps?