The tower on top of this building is not meshed you can clip through and fall through the building. Again if I could post pictures I would but the forum doesn't allow me to do so.

Fallout 4 is overwhelmingly undeveloped. There are entire buildings that are not meshed in and around the downtown Boston area where you can clip through them completely. I keep finding more and more buildings that I can clip through, it's really annoying when you're trying to move around from rooftop to rooftop, only to have you fall through the map or worldspace.