Interior VIsible Mesh Collision causing Freezing

I'm wondering how to fix this problem. I have some house interiors that I'm trying to use. Some I've found and others that I have thrown together in SweetHome 3D. I can walk around the outside of the "house" and collision works fine with no lag. As soon as I walk inside the structure and touch an interior wall or door Torque freezes for awhile then I can walk for a second before it freezes again. I've tried placing the interior inside a zone but still no help.This has brought my next phase to a stand still.

Any idea what is happening?


Edit: I think I may have figured this out myself. I think that this may be caused by thin meshes. When I changed the wall thickness in SweetHome 3d the problem seemed to go away. Does that sound feasible?