Does anyone know what the standard is for the route of campus fiber backbone?

We are replacing our fiber network with a multi-cored ring to connect 10 buildings. Our shortest (and possibly cheapest) route is to go through some buildings, rather than around them. For example, we might bring the fiber into the library on one side of the building to the IDF, and then take it out through the other side.

Something is telling me that we shoud be routing the fiber completely outside; and then splicing and bringing into the building only those fibers that service that building. This would make future renovations easier.... I think....

I have been trying to find an online resource for an answer, but no luck yet. Does anyone know if there is a standard on this?

Thanks,