Haha.. You'll have to forgive me. When you mentioned 'closed building' before I thought you were being metaphorical as to the state of the code not being open, thus my last reply was out of context.

I agree that sometimes closed rooms demonstrate lower geometry based on visibility distance, but with even rudimentary LOD, this can be rendered moot. For example, given the pictures in my past post, you can trace the edges of the hills and notice that the scene would not actually require terribly high geometry. In this case, the graphical quality is in the textures, not the geometry!