Occlusion culling problem

Hey guys, me and a friend are working on a project which we need to use occlusion culling for. We've googled for a while but couldn't reach any conclusions.
The Problem
When inside of our buildings, occasionally, the walls will be culled leaving gaps in geometry when moving around the rooms. This issue can be seen in image below.



We have tried experimenting with the smallest occluder by increasing and decreasing the value but it had next to no effect on the end result. I have a hunch its something to do with how the buildings are created as they are made up from multiple wall pieces. We have also tried changing the ocludee and ocluder static options on the mesh renders but again it didn't remove the problem.


Any help is greatly appreciated. happy to post more screenshots and more information about our scene where i can.